TY - JOUR A1 - Ye, Mingyu A1 - Wilhelm, Martina A1 - Gentschev, Ivaylo A1 - Szalay, Aladár T1 - A modified limiting dilution method for monoclonal stable cell line selection using a real-time fluorescence imaging system: A practical workflow and advanced applications JF - Methods and Protocols N2 - Stable cell lines are widely used in laboratory research and pharmaceutical industry. They are mainly applied in recombinant protein and antibody productions, gene function studies, drug screens, toxicity assessments, and for cancer therapy investigation. There are two types of cell lines, polyclonal and monoclonal origin, that differ regarding their homogeneity and heterogeneity. Generating a high-quality stable cell line, which can grow continuously and carry a stable genetic modification without alteration is very important for most studies, because polyclonal cell lines of multicellular origin can be highly variable and unstable and lead to inconclusive experimental results. The most commonly used technologies of single cell originate monoclonal stable cell isolation in laboratory are fluorescence-activated cell sorting (FACS) sorting and limiting dilution cloning. Here, we describe a modified limiting dilution method of monoclonal stable cell line selection using the real-time fluorescence imaging system IncuCyte\(^®\)S3. KW - monoclonal stable cell KW - limiting dilution cloning KW - ncuCyte\(^®\)S3 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228896 VL - 4 IS - 1 ER - TY - JOUR A1 - Boetzl, Fabian A. A1 - Schuele, Maren A1 - Krauss, Jochen A1 - Steffan‐Dewenter, Ingolf T1 - Pest control potential of adjacent agri‐environment schemes varies with crop type and is shaped by landscape context and within‐field position JF - Journal of Applied Ecology N2 - Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri‐environmental schemes (AES) on natural pest control and within‐field distance functions of natural pest control agents have rarely been addressed but might affect the distribution of biocontrol providers. Importantly, it is currently unknown whether ecosystem services provided by adjacent AES are consistent for different crop types during crop rotation. In this study, we assessed whether crop rotation from oilseed rape to cereals altered within‐field distance functions of ground‐dwelling predators from adjacent agri‐environmental fields along a gradient in landscape context. Additionally, we recorded crop pests, predation rates, parasitoids as well as crop yields on a total of 30 study sites. Distance functions varied between trophic levels: Carabid richness decreased while densities of carabid beetles, staphylinid beetles as well as crop yields increased towards the field centres. Distance functions of parasitoids and pests were modulated by the amount of semi‐natural habitat in the surrounding landscape, while the effects of adjacent AES were limited. Distance decay functions found for ground‐dwelling predators in oilseed rape in the previous year were not always present in cereals. Increasing distance to the field edge also increased effects of crop rotation on carabid beetle assemblages, indicating a source habitat function of field edges. Synthesis and applications. Distance functions of natural pest control are not universal and the effects of agri‐environmental schemes (AES) in different adjacent crops during crop rotation vary and depend on ecological contrasts. A network of semi‐natural habitats and spatially optimized AES habitats can benefit pest control in agricultural landscapes, but constraints as a result of crop type need to be addressed by annually targeted, spatially shifting agri‐environment schemes for different crops. KW - cereals KW - distance gradient KW - ecological intensification KW - ecosystem services KW - ground‐dwelling predators KW - parasitoids KW - pest control KW - semi‐natural habitats Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218265 VL - 57 IS - 8 SP - 1482 EP - 1493 ER - TY - JOUR A1 - Lamatsch, D. K. A1 - Trifonov, V. A1 - Schories, S. A1 - Epplen, J. T. A1 - Schmid, M. A1 - Schartl, M. T1 - Isolation of a Cancer-Associated Microchromosome in the Sperm-Dependent Parthenogen Poecilia formosa JF - Cytogenetic and Genome Research N2 - In the asexual all-female fish species Poecilia formosa, the Amazon molly, supernumerary chromosomes have frequently been found in both laboratory-reared and wild-caught individuals. While wild-caught individuals with B chromosomes are phenotypically indifferent from conspecifics, individuals carrying B chromosomes from recent introgression events in the laboratory show phenotypic changes. Former analyses showed that the expression of a pigment cell locus is associated with the presence of these B chromosomes. In addition, they contain a so far unidentified locus that confers a higher susceptibility to tumor formation in the presence of pigmentation pattern. Isolation by microdissection and hybridization to metaphase chromosomes revealed that they contain one or several sequences with similarity to a highly repetitive pericentromeric and subtelomeric sequence in A chromosomes. Isolation of one particular sequence by AFLP showed that the B chromosomes contain at least 1 copy of an A-chromosomal region which is highly conserved in the whole genus Poecilia, i.e. more than 5 million years old. We propose it to be a single copy sequence. KW - paternal introgression KW - AFLP KW - asexual reproduction KW - B chromosomes KW - gynogenesis KW - microdissection KW - telomeres Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196785 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 135 IS - 2 ER - TY - JOUR A1 - Habenstein, Jens A1 - Amini, Emad A1 - Grübel, Kornelia A1 - el Jundi, Basil A1 - Rössler, Wolfgang T1 - The brain of Cataglyphis ants: Neuronal organization and visual projections JF - Journal of Comparative Neurology N2 - Cataglyphis ants are known for their outstanding navigational abilities. They return to their inconspicuous nest after far‐reaching foraging trips using path integration, and whenever available, learn and memorize visual features of panoramic sceneries. To achieve this, the ants combine directional visual information from celestial cues and panoramic scenes with distance information from an intrinsic odometer. The largely vision‐based navigation in Cataglyphis requires sophisticated neuronal networks to process the broad repertoire of visual stimuli. Although Cataglyphis ants have been subjected to many neuroethological studies, little is known about the general neuronal organization of their central brain and the visual pathways beyond major circuits. Here, we provide a comprehensive, three‐dimensional neuronal map of synapse‐rich neuropils in the brain of Cataglyphis nodus including major connecting fiber systems. In addition, we examined neuronal tracts underlying the processing of visual information in more detail. This study revealed a total of 33 brain neuropils and 30 neuronal fiber tracts including six distinct tracts between the optic lobes and the cerebrum. We also discuss the importance of comparative studies on insect brain architecture for a profound understanding of neuronal networks and their function. KW - 3D reconstruction KW - ant brain KW - antennal lobes KW - central complex KW - insect KW - mushroom bodies KW - optical tracts Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218212 VL - 528 IS - 18 SP - 3479 EP - 3506 ER - TY - JOUR A1 - Stieb, Sara Mae A1 - Kelber, Christina A1 - Wehner, Rüdiger A1 - Rössler, Wolfgang T1 - Antennal-Lobe Organization in Desert Ants of the Genus Cataglyphis JF - Brain, Behavior and Evolution N2 - Desert ants of the genus Cataglyphis possess remarkable visual navigation capabilities. Although Cataglyphis species lack a trail pheromone system, Cataglyphis fortis employs olfactory cues for detecting nest and food sites. To investigate potential adaptations in primary olfactory centers of the brain of C. fortis, we analyzed olfactory glomeruli (odor processing units) in their antennal lobes and compared them to glomeruli in different Cataglyphis species. Using confocal imaging and 3D reconstruction, we analyzed the number, size and spatial arrangement of olfactory glomeruli in C. fortis, C.albicans, C.bicolor, C.rubra, and C.noda. Workers of all Cataglyphis species have smaller numbers of glomeruli (198–249) compared to those previously found in olfactory-guided ants. Analyses in 2 species of Formica – a genus closely related to Cataglyphis – revealed substantially higher numbers of olfactory glomeruli (c. 370), which is likely to reflect the importance of olfaction in these wood ant species. Comparisons between Cataglyphis species revealed 2 special features in C. fortis. First, with c. 198 C. fortis has the lowest number of glomeruli compared to all other species. Second, a conspicuously enlarged glomerulus is located close to the antennal nerve entrance. Males of C. fortis possess a significantly smaller number of glomeruli (c. 150) compared to female workers and queens. A prominent male-specific macroglomerulus likely to be involved in sex pheromone communication occupies a position different from that of the enlarged glomerulus in females. The behavioral significance of the enlarged glomerulus in female workers remains elusive. The fact that C. fortis inhabits microhabitats (salt pans) that are avoided by all other Cataglyphis species suggests that extreme ecological conditions may not only have resulted in adaptations of visual capabilities, but also in specializations of the olfactory system. KW - olfactory glomeruli KW - plasticity KW - ant KW - antennal lobe KW - glomerulus KW - insects KW - interspecific comparison KW - macroglomerulus KW - olfaction Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196815 SN - 0006-8977 SN - 1421-9743 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 77 IS - 3 ER - TY - JOUR A1 - Stiegler, Jonas A1 - von Hoermann, Christian A1 - Müller, Jörg A1 - Benbow, M. Eric A1 - Heurich, Marco T1 - Carcass provisioning for scavenger conservation in a temperate forest ecosystem JF - Ecosphere N2 - Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far‐reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species. KW - anthropogenic food subsidies KW - carrion ecology KW - diversity KW - nature conservation KW - necrobiome KW - vertebrate scavenger KW - wildlife management Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218054 VL - 11 IS - 4 ER - TY - JOUR A1 - Doerfler, Inken A1 - Cadotte, Marc W. A1 - Weisser, Wolfgang W. A1 - Müller, Jörg A1 - Gossner, Martin M. A1 - Heibl, Christoph A1 - Bässler, Claus A1 - Thorn, Simon A1 - Seibold, Sebastian T1 - Restoration‐oriented forest management affects community assembly patterns of deadwood‐dependent organisms JF - Journal of Applied Ecology N2 - Land‐use intensification leads to loss and degradation of habitats and is thus a major driver of biodiversity loss. Restoration strategies typically focus on promoting biodiversity but often neglect that land‐use intensification could have changed the underlying mechanisms of community assembly. Since assembly mechanisms determine the diversity and composition of communities, we propose that evaluation of restoration strategies should consider effects of restoration on biodiversity and community assembly. Using a multi‐taxon approach, we tested whether a strategy that promotes forest biodiversity by restoring deadwood habitats also affects assembly patterns. We assessed saproxylic (i.e. deadwood‐dependent) beetles and fungi, as well as non‐saproxylic plants and birds in 68 beech forest plots in southern Germany, 8 years after the commencement of a restoration project. To assess changes in community assembly, we analysed the patterns of functional–phylogenetic diversity, community‐weighted mean (CWM) traits and their diversity. We hypothesized that restoration increases habitat amount and heterogeneity of deadwood and reduces canopy cover and thereby decreases the strength of environmental filters imposed by past silvicultural intensification, such as a low amount in deadwood. With the restoration of deadwood habitats, saproxylic beetle communities became less functionally–phylogenetically similar, whereas the assembly patterns of saproxylic fungi and non‐saproxylic taxa remained unaffected by deadwood restoration. Among the traits analysed, deadwood diameter niche position of species was most strongly affected indicating that the enrichment of large deadwood objects led to lower functional–phylogenetical similarity of saproxylic beetles. Community assembly and traits of plants were mainly influenced by microclimate associated with changes in canopy cover. Synthesis and applications. Our results indicate that the positive effects of deadwood restoration on saproxylic beetle richness are associated with an increase in deadwood amount. This might be linked to an increase in deadwood heterogeneity, and therefore decreasing management‐induced environmental filters. Deadwood enrichment can thus be considered an effective restoration strategy which reduces the negative effects of intense forest management on saproxylic taxa by not only promoting biodiversity but also by decreasing the environmental filters shaping saproxylic beetle communities, thus allowing the possibly for more interactions between species and a higher functional diversity. KW - assembly mechanisms KW - beech forest KW - community‐weighted mean KW - deadwood enrichment KW - habitat heterogeneity KW - restoration strategy KW - saproxylic species KW - species traits Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-217918 VL - 57 IS - 12 SP - 2429 EP - 2440 ER - TY - THES A1 - Georgiev, Kostadin T1 - Sustainable management of naturally disturbed forests T1 - Nachhaltiges Management von natürlichen Störungen in Wäldern N2 - Owing to climate change, natural forest disturbances and consecutive salvage logging are drastically increasing worldwide, consequently increasing the importance of understanding how these disturbances would affect biodiversity conservation and provision of ecosystem services. In chapter II, I used long-term water monitoring data and mid-term data on α-diversity of twelve species groups to quantify the effects of natural disturbances (windthrow and bark beetle) and salvage logging on concentrations of nitrate and dissolved organic carbon (DOC) in streamwater and α-diversity. I found that natural disturbances led to a temporal increase of nitrate concentrations in streamwater, but these concentrations remained within the health limits recommended by the World Health Organization for drinking water. Salvage logging did not exert any additional impact on nitrate and DOC concentrations, and hence did not affect streamwater quality. Thus, neither natural forest disturbances in watersheds nor associated salvage logging have a harmful effect on the quality of the streamwater used for drinking water. Natural disturbances increased the α-diversity in eight out of twelve species groups. Salvage logging additionally increased the α-diversity of five species groups related to open habitats, but decreased the biodiversity of three deadwood-dependent species groups. In chapter III, I investigated whether salvage logging following natural disturbances (wildfire and windthrow) altered the natural successional trajectories of bird communities. I compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, over a period of 17 years and tested whether bird community dissimilarities changed over time for taxonomic, functional and phylogenetic diversity when rare, common and dominant species were weighted differently. I found that salvage logging led to significantly larger dissimilarities than expected by chance and that these dissimilarities persisted over time for rare, common and dominant species, evolutionary lineages, and for rare functional groups. Dissimilarities were highest for rare, followed by common and dominant species. In chapter IV, I investigated how β-diversity of 13 taxonomic groups would differ in intact, undisturbed forests, disturbed, unlogged forests and salvage-logged forests 11 years after a windthrow and salvage logging. The study suggests that both windthrow and salvage logging drive changes in between-treatment β-diversity, whereas windthrow alone seems to drive changes in within-treatment β-diversity. Over a decade after the windthrow at the studied site, the effect of subsequent salvage logging on within-treatment β-diversity was no longer detectable but the effect on between-treatment β-diversity persisted, with more prominent changes in saproxylic groups and rare species than in non-saproxylic groups or common and dominant species. Based on these results, I suggest that salvage logging needs to be carefully weighed against its long-lasting impact on communities of rare species. Also, setting aside patches of naturally disturbed areas is a valuable management alternative as these patches would enable post-disturbance succession of bird communities in unmanaged patches and would promote the conservation of deadwood-dependent species, without posing health risks to drinking water sources. N2 - In Folge des Klimawandels treten in Wäldern vermehrt natürliche Störungen auf, wodurch wiederum die Zahl an nachfolgenden Sanitärhieben (Räumungen) drastisch gestiegen ist. Wie sich natürliche Störungen und Sanitärhiebe auf die biologische Vielfalt und die Bereitstellung von Ökosystemleistungen auswirken können, ist bisher jedoch nur unzureichend bekannt. In Kapitel II nutzte ich langfristige Wassermonitoringdaten und mittelfristige Biodiversitätsdaten über zwölf Artengruppen, um die Effekte von natürlichen Störungen (Windwurf und Borkenkäfer) und Sanitärhieben auf die Konzentrationen von Nitraten und gelöster organischer Kohlenstoffe (GOK) in Bächen und Artenzahl zu quantifizieren. Die Ergebnisse zeigen, heraus, dass natürliche Störungen zu einer temporären Erhöhung der Nitratwerte führen, welche dennoch laut Angaben der Weltgesundheitsorganisation immer noch als unbedenklich eingestuft werden können. Die Sanitärhiebe hatten keinen zusätzlichen Einfluss auf die Nitrat- und GOK-Konzentrationen und daher keinen Einfluss auf die Wasserqualität. Daraus lässt sich schließen, dass sich weder natürliche Waldstörungen in Wassereinzugsgebieten noch die damit verbundenen Sanitärhiebe auf die Trinkwasserqualität aus auswirken. Natürliche Störungen erhöhten die Artenzahlen in acht von zwölf Artengruppen. Zusätzlich erhöhten die Sanitärhiebe die Artenzahlen von fünf Artengruppen, welche auf offene Lebensräume angewiesen sind, verringerte jedoch die Artenzahlen von drei xylobionte Artengruppen. In Kapitel III habe ich untersucht, ob Sanitärhiebe nach natürlichen Waldstörungen zu sukzessiven Veränderungen der Vogelgemeinschaften führen. Hierzu habe ich die taxonomische, funktionelle und phylogenetische Diversität von Brutvogelgemeinschaften aus neun Untersuchungsregionen in Nordamerika, Europa und Asien über die Zeit von 17 Jahren verglichen und analysiert, ob sich das jeweilige Diversitätsmaß verändert, wenn seltene, häufige und dominante Arten unterschiedlich gewichtet werden. Ich konnte zeigen, dass Sanitärhiebe zu signifikant größeren Unterschieden geführt haben als zufällig zu erwarten gewesen sind und dass diese Unterschiede über die Zeit sowohl für seltene, häufige und dominante Arten, als auch für evolutionäre Linien, und funktionelle Gruppen fortdauern. Diese Unterschiede waren am größten für seltene, gefolgt von häufigen und dominanten Arten. In Kapitel IV untersuchte ich wie sich die β-Diversität von 13 taxonomischen Gruppen zwischen ungestörten Wäldern, gestörten und ungeräumten Wäldern sowie gestörten und geräumten Wäldern 11 Jahre nach Windwurf und anschließender Räumung unterscheidet. Die Ergebnisse deuten darauf hin, dass sowohl Windwurf als auch Räumung Änderungen in der β-Diversität bewirken. Windwurf allein jedoch scheint diese Änderungen in der β-Diversität innerhalb der Behandlung bewirken zu können. Über ein Jahrzehnt nach dem Windwurf war der Effekt des Sanitärhiebes auf die β-Diversität innerhalb der Behandlung nicht mehr nachweisbar. Der Effekt auf die β-Diversität zwischen den Behandlungen blieb jedoch bestehen, wobei sich die xylobionten Gruppen und seltenen Arten stärker veränderten als die nicht-xylobionten Gruppen oder häufigen und dominanten Arten. Basierend auf diesen Ergebnissen schlage ich vor, dass der Einsatz von Sanitärhieben sorgfältig gegen ihre langfristigen Auswirkungen auf Gemeinschaften seltener Arten abgewogen werden muss. Zusätzlich, besteht mit dem Belassen von natürlich gestörten Waldgebieten eine wertvolle Managementalternative, da diese Flächen eine natürliche Entwicklung von Vogelgemeinschaften ermöglichen und xylobionte Arten fördern, ohne dass die Trinkwasserqualität negativ beeinträchtigt wird. KW - species richness KW - water quality KW - beta diversity KW - Hill numbers KW - post-disturbance logging KW - biodiversity response KW - ecosystem services Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242854 ER - TY - THES A1 - Röschert, Isabelle T1 - Aurora-A prevents transcription-replication conflicts in MYCN-amplified neuroblastoma T1 - Aurora-A verhindert Transkriptions-Replikationskonflikte in MYCN-amplifizierten Neuroblastomen N2 - Neuroblastoma is the most abundant, solid, extracranial tumor in early childhood and the leading cause of cancer-related childhood deaths worldwide. Patients with high-risk neuroblastoma often show MYCN-amplification and elevated levels of Aurora-A. They have a low overall survival and despite multimodal therapy options a poor therapeutic prognosis. MYCN-amplified neuroblastoma cells depend on Aurora-A functionality. Aurora-A stabilizes MYCN and prevents it from proteasomal degradation by competing with the E3 ligase SCFFBXW7. Interaction between Aurora-A and MYCN can be observed only in S phase of the cell cycle and activation of Aurora-A can be induced by MYCN in vitro. These findings suggest the existence of a profound interconnection between Aurora-A and MYCN in S phase. Nevertheless, the details remain elusive and were investigated in this study. Fractionation experiments show that Aurora-A is recruited to chromatin in S phase in a MYCN-dependent manner. Albeit being unphosphorylated on the activating T288 residue, Aurora-A kinase activity was still present in S phase and several putative, novel targets were identified by phosphoproteomic analysis. Particularly, eight phosphosites dependent on MYCN-activated Aurora-A were identified. Additionally, phosphorylation of serine 10 on histone 3 was verified as a target of this complex in S phase. ChIP-sequencing experiments reveal that Aurora-A regulates transcription elongation as well as histone H3.3 variant incorporation in S phase. 4sU-sequencing as well as immunoblotting demonstrated that Aurora-A activity impacts splicing. PLA measurements between the transcription and replication machinery revealed that Aurora-A prevents the formation of transcription-replication conflicts, which activate of kinase ATR. Aurora-A inhibitors are already used to treat neuroblastoma but display dose-limiting toxicity. To further improve Aurora-A based therapies, we investigated whether low doses of Aurora-A inhibitor combined with ATR inhibitor could increase the efficacy of the treatment albeit reducing toxicity. The study shows that the combination of both drugs leads to a reduction in cell growth as well as an increase in apoptosis in MYCN-amplified neuroblastoma cells, which is not observable in MYCN non-amplified neuroblastoma cells. This new approach was also tested by a collaboration partner in vivo resulting in a decrease in tumor burden, an increase in overall survival and a cure of 25% of TH-MYCN mice. These findings indicate indeed a therapeutic window for targeting MYCN-amplified neuroblastoma. N2 - Das Neuroblastom ist der häufigste, solide, extrakranielle Tumor der frühesten Kindheit und die häufigste mit Krebs verbundene Todesursache von Kleinkindern weltweit. Patienten mit geringerer Überlebenswahrscheinlichkeit und schlechterer Therapieprognose zeigen oft eine MYCN-Amplifikation und erhöhte Mengen von Aurora-A. Aurora-A ist eine Serin/Threonin-Protein Kinase, die wichtige mitotische Prozesse reguliert. Aurora-A stabilisiert MYCN und verhindert dadurch den proteasomalen Abbau von MYCN. Die Interaktion zwischen Aurora-A und MYCN ist S Phasen-spezifisch und MYCN ist in vitro in der Lage, durch seine Bindung Aurora-A zu aktivieren. Die Funktionen und Prozesse, die von Aurora-A in der S Phase reguliert werden, sind noch nicht hinreichend untersucht und daher Gegenstand dieser Dissertation. Zell-Fraktionierungen zeigen, dass Aurora-A in der S Phase in einer MYCN-abhängigen Weise an das Chromatin gebunden ist. Phosphoproteom-Analysen mittels Massenspektrometrie identifizierten zahlreiche neue Substrate von Aurora-A, sowie acht Substrate von MYCN-aktiviertem Aurora-A. Zusätzlich konnte gezeigt werden, dass Histon 3 Serin 10 von Aurora-A in Abhängigkeit von MYCN in S Phase phosphoryliert wird. ChIP-Sequenzierungen zeigen, dass Aurora-A die Elongation der Transkription und den Einbau der Histone Variante H3.3 in S Phase beeinflusst. 4sU-Sequenzierung sowie Immunoblots zeigen einen Zusammenhang zwischen der Aktivität von Aurora-A und dem Spleißosom in der S Phase. Zusätzlich konnte mittels PLA nachgewiesen werden, dass Aurora-A die Entstehung von Transkriptions-Replikationskonflikten verhindert, die andernfalls die Kinase ATR aktivieren würden. Aurora-A Inhibitoren wurden unter anderem zur Therapie von Neuroblastomen eingesetzt, allerdings ist die Dosis des Aurora-A Inhibitors durch die hohe Toxizität limitiert, was die Effizienz der Therapie stark beeinträchtigt. Daher wurde untersucht, ob die gleichzeitige Gabe von geringeren Mengen Aurora-A Inhibitor in Kombination mit einem ATR Inhibitor zur Therapie geeignet ist. In vitro konnte gezeigt werden, dass die Kombination beider Inhibitoren das Zellwachstum reduziert und das MYCN-amplifizierte Zellen im Vergleich zu MYCN nicht-amplifizierten Zellen verstärkt durch Apoptose sterben. Durch einen Kollaborationspartner konnte die Kombination der beiden Inhibitoren an Mäusen getestet werden. Die mit der Kombination behandelten Mäuse, zeigen ein deutlich reduziertes Tumorwachstum, sowie längeres Überleben. Somit stellt diese Kombination ein therapeutisches Fenster dar und könnte zur Behandlung von Neuroblastompatienten genutzt werden. KW - Neuroblastom KW - Aurora-A KW - MYCN KW - neuroblastoma Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-243037 ER - TY - THES A1 - López Arboleda, William Andrés T1 - Global Genetic Heterogeneity in Adaptive Traits T1 - Globale genetische Heterogenität in adaptiven Merkmalen N2 - Genome Wide Association Studies (GWAS) have revolutionized the way on how genotype-phenotype relations are assessed. In the 20 years long history of GWAS, multiple challenges from a biological, computational, and statistical point of view have been faced. The implementation of this technique using the model plant species Arabidopsis thaliana, has enabled the detection of many association for multiple traits. Despite a lot of studies implementing GWAS have discovered new candidate genes for multiple traits, different samples are used across studies. In many cases, either globally diverse samples or samples composed of accessions from a geographically restricted area are used. With the aim of comparing GWAS outcomes between populations from different geographic areas, this thesis describes the performance of GWAS in different European samples of A. thaliana. Here, association mapping results for flowering time were compared. Chapter 2 describes the analyses of random resampling from this original sample. The aim was to establish reduced subsamples to later carry out GWAS and compare the outcomes between these subsamples. In Chapter 3, the European sample was split into eight equally-sized local samples representing different geographic regions. Next, GWAS was carried out and an attempt was made to clarify the differences in GWAS outcomes. Chapter 4 contains the results of a collaboration with Prof. Dr. Wolfgang Dröge- Laser, in which my mainly task was the analysis of RNAseq data from A. thaliana plants infected by pathogenic fungi. Finally, Appendix A presents a very short description of my participation in the GHP Project on Access to Care for Cardiometabolic Diseases (HPACC) at the university of Heidelberg. N2 - Die genomweiten Assoziationsstudien (GWAS) haben die Art und Weise revolutionierten, wie genotypische-phänotypische Zusammenhänge untersucht werden. In der 20-jährigen Geschichte dieser Analysen, gab es zahlreiche biologische, mathematische und statistische Herausforderungen. Die Anwendung dieser Methodik in der Modellpflanze Arabidopsis thaliana ermöglichte die Erkennung neuer Zusammenhänge für zahlreicher Merkmale. Obwohl viele Studien, die GWAS implementieren, neue Kandidatengene für verschiedene Merkmale entdeckt haben, werden in den verschiedenen Analysen oft unterschiedliche Populationen verwendet. Es werden entweder global unterschiedliche Accessionen oder alternative welche aus einem geografisch begrenzten Gebiet als Population für die Anaylsen verwendet. Mit dem Ziel, GWAS-Ergebnisse zwischen Populationen aus verschiedenen geografischen Gebieten zu vergleichen, beschreibt diese Arbeit die Eigenschaften der Analyse in verschiedenen europäischen Populationen von A. thaliana. Verglichen wurden die Ergebnisse der Assoziationskartierung für die Blütezeit. Kapitel 2 beschreibt die Analysen von zufälligen Populationen im Vergleich zur gesamten europäischen Population. Ziel war es, reduzierte Stichproben zu erstellen, um später GWAS durchzuführen und die Ergebnisse zwischen diesen Stichproben zu vergleichen. In Kapitel 3 wurde die europäische Population in acht gleich große lokale Subpopulationen aufgeteilt. Diese repräsentieren verschiedene geografische Regionen. Als nächstes wurde GWAS durchgeführt und die Unterschiede in den jeweilgen GWAS-Ergebnissen beschrieben. Kapitel 4 behinhaltet die Ergebnisse aus einer Zusammenarbeit mit Prof. Dr. Wolfgang Dröge-Laser: Hier war meine Hauptaufgabe die Analyse von RNAs Sequenzierungsdaten von mit pathogenen Pilzen befallenen A. thaliana-Pflanzen. Schließlich enthält Anhang A eine zusammenfassende Beschreibung meiner Mitarbeit am GHP-Projekt zum Zugang zur Versorgung bei kardiometabolischen Erkrankungen (HPACC) an der Universität Heidelberg KW - Genotype-phenotype relationship KW - GWAS KW - adaptive traits KW - local adaptation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242468 ER - TY - THES A1 - Bögelein, Anna T1 - Einfluss systemischer Therapeutika auf die CXCR4-Expression von Myelomzellen T1 - Influence of therapeutic agents on CXCR4 expression of myeloma cells N2 - Im Zuge der Bemühungen um neue, tumorspezifische Therapieansätze für die Myelomerkrankung hat sich der C-X-C-Chemokinrezeptor 4 (CXCR4) aufgrund seiner zentralen Rolle in der Tumorgenese als vielversprechender Angriffspunkt hervorgetan. Im Sinne eines theranostischen Konzepts wird der Rezeptor mithilfe eines radioaktiv markierten Liganden quantifiziert und anschließend von rezeptorspezifischen Radiotherapeutika als Zielstruktur genutzt. Die CXCR4-Expression ist allerdings ein höchst dynamischer Prozess mit großer inter- und intraindividueller Heterogenität, der u.a. durch eine begleitende Chemotherapie beeinflusst werden kann. Ob sich therapieinduzierte Veränderungen der Rezeptorexpression gezielt nutzen lassen, um die CXCR4-Expression zu optimieren und so die Effektivität der CXCR4-gerichteten Strategien zu steigern, wurde bislang nicht untersucht. Vor diesem Hintergrund wurden in der vorliegenden Arbeit verschiedene, in der Myelomtherapie etablierte Substanzen sowohl einzeln als auch in Kombination hinsichtlich ihres Einflusses auf die CXCR4-Expression von MM-Zelllinien und primären MM-Zellen unter in vitro Bedingungen analysiert. In den durchgeführten Experimenten zeigte sich eine hohe Variabilität der CXCR4-Expression der MM-Zellen nach Therapieinduktion, die sich als substanz-, dosis- und zeitabhängig herausstellte. Die Ergebnisse bestätigten das große Potenzial der therapieinduzierten Modulation der CXCR4-Expression. Im weiteren Verlauf sind translationale Forschungsansätze gerechtfertigt, die die Übertragbarkeit der in vitro gewonnenen Ergebnisse auf die komplexen Vorgänge im lebenden Organismus überprüfen. Langfristiges Ziel ist der Entwurf eines patientenzentrierten, multimodalen Therapiekonzepts, welches das CXCR4-gerichtete theranostische Konzept mit einer individuell angepassten, medikamentösen MM-Therapie kombiniert. N2 - In the course of developing new tumor specific therapeutic approaches for non-yet curable myeloma disease C-X-C chemokine receptor 4 (CXCR4) has emerged as a promising target due to its crucial role in myeloma tumorigenesis. Within a theranostic concept CXCR4 is quantified using radioactively labeled ligands and afterwards targeted by receptor-specific radiopharmaceuticals. However, CXCR4 expression is a very dynamic process with a high inter- and intraindividual heterogeneity which can be influenced by concomitant chemotherapy. Whether therapy induced changes in receptor expression can be used to enhance CXCR4 expression and thus to improve efficacy of CXCR4-based theranostics has not been examined so far. In this context the present study evaluated the effect of several anti-myeloma drugs (bortezomib, cyclophosphamide, dexamethasone, doxorubicin, lenalidomide) on CXCR4 expression of different human myeloma cell lines as well as patient-derived CD138+ plasma cells under in vitro conditions. Findings disclosed a high variability of CXCR4 expression on myeloma cells after drug application which turned out to be substance-, dose- and time-dependent. The results confirmed the high potential of therapy-induced modulation of CXCR4 expression. In further course, translational research approaches are justified to verify the transferability of the in vitro findings to the complex macro- and microenvironment in vivo. Long-term goal is the development of a patient-centered, multimodal therapy concept which combines CXCR4 based theranostics with a personalized drug-based therapy. KW - Plasmozytom KW - In vitro KW - Multiples Myelom KW - Theranostik KW - CXCR4 KW - Gallium-68 Pentixafor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241746 ER - TY - THES A1 - da Cruz Güerisoli, Irene Maria T1 - Investigating the murine meiotic telomere complex TERB1-TERB2-MAJIN: spatial organization and evolutionary history T1 - Untersuchung des murinen meiotischen Telomer-Komplex TERB1-TERB2-MAJIN: spatiale Organisation und Evolutionsgeschichte N2 - Einess der faszinierenden Merkmale der meiotischen Prophase I sind die hochkonservierten kräftigen Bewegungen homologer Chromosomen. Diese Bewegungen sind entscheidend für den Erfolg von Schlüsselereignissen wie die Ausrichtung, Paarung und Rekombination der homologen Chromosomen. Mehrere bisher untersuchte Organismen, darunter Säugetiere, Würmer, Hefen und Pflanzen, erreichen diese Bewegungen, indem sie die Chromosomenenden an spezialisierten Stellen in der Kernhülle verankern. Diese Verankerung erfordert Telomer-Adapterproteine, die bisher in der Spalthefe und der Maus identifiziert wurden. Die meiosespezifischen Telomer-Adapterproteine der Maus, TERB1, TERB2 und MAJIN, sind an der Verankerung des ubiquitären Telomer-Shelterin-protein an den LINC-Komplex beteiligt, mit einem analogen Mechanismus, wie er die Spalthefe beschrieben wird. Obgleich die meiose-spezifischen TelomerAdapterproteine eine wesentliche Rolle spielen, ist der genaue Mechanismus der Verankerung der Telomere an die Kernhülle sowie ihre evolutionäre Geschichte bisher noch wenig verstanden. Das Hauptziel dieser Arbeit ist daher die Untersuchung der Organisation des meiosespezifischen TelomerAdapterkomplexes TERB1-TERB2-MAJIN der Maus und dessen Evolutionsgeschichte. Im ersten Teil dieser Arbeit wurde die Organisation des TERB1-TERB2-MAJIN Komplexes mittels hochauflösender Mikroskopie (SIM), an Mausspermatozyten untersucht, sowie die Lokalisation in Bezug auf TRF1 des Telomer-ShelterinKomplexes und die telomerische DNA analysiert. In den Stadien Zygotän und Pachytän zeigten die Fluoreszenzsignale eine starke Überlappung der Verteilung der meiotischen Telomer-Komplex-Proteine, wobei die Organisation von TERB2 an den Chromosomenenden heterogener war als die von TERB1 und MAJIN. Außerdem konnte die TRF1-Lokalisation an den Enden der Lateralelemente (LEs) mit einer griffartigen Anordnung um die TERB1- und MAJIN-Signale im Zygotän- und Pachytän-Stadium gezeigt werden. Interessanterweise erwies sich die telomerische DNA als lateral verteilt und teilweise überlappend mit der zentralen Verteilung der meiotischen Telomer-Komplex-Proteine an den Enden der LEs. Die Kombination dieser Ergebnisse erlaubte die Beschreibung eines alternativen Modells der Verankerung der Telomer an die Kernhülle während der meiotischen Prophase I. Der zweite Teil dieser Arbeit analysiert die Evolutionsgeschichte der Mausproteine von TERB1, TERB2 und MAJIN. Die fehlende Übereinstimmung zwischen den Meiose-spezifische Telomer-Adapteproteinen der Maus und der Spalthefe hat die Frage nach dem evolutionsbedingten Ursprung dieses spezifischen Komplexes aufgeworfen. Um vermeintliche Orthologen der Mausproteinevon TERB1, TERB2 und MAJIN über Metazoen hinweg zu identifizieren, wurden computergestützte Verfahren und phylogenetische Analysen durchgeführt. Darüber hinaus wurden Expressionsstudien implementiert, um ihre potenzielle Funktion während der Meiose zu testen. Die Analysen haben ergeben, dass der Meiose-spezifische Telomer-Komplex der Maus sehr alt ist, da er bereits in den Eumetazoen entstand, was auf einen einzigen Ursprung hindeutet. Das Fehlen jeglicher Homologen des meiosespezifischen Telomerkomplexes in Nematoden und die einigen wenigen in Arthropoden nachgewiesenen Kandidaten, deuten darauf hin, dass die Telomer-Adapterproteine in diesen Abstammungslinien verloren/ersetzt oder stark diversifiziert worden sind. Bemerkenswerterweise zeigten Proteindomänen von TERB1, TERB2 und MAJIN, die an der Bildung des Komplexes sowie an der Interaktion mit dem Telomer-Shelterin-Protein und den LINC-Komplexen beteiligt sind, eine hohe Sequenzähnlichkeit über alle Kladen hinweg. Abschließend lieferte die Genexpression im Nesseltier Hydra vulgaris den Beweis, dass der TERB1-TERB2-MAJIN-Komplex selektiv in der Keimbahn exprimiert wird, was auf die Konservierung meiotischer Funktionen über die gesamte Metazoen-Evolution hinweg hindeutet. Zusammenfassend bietet diese Arbeit bedeutende neue Erkenntnisse hinsichtlich des Meiose-spezifischen Telomer-Adapterkomplex, seines Mechanismus zur Verankerung der Telomer an die Kernhülle und die Entschlüsselung seines Ursprungs in den Metazoen. N2 - One of the fascinating features of meiotic prophase I, is the highly conserved vigorous movements of homologous chromosomes. These movements are critical for the success of essential events as homologs alignment, synapsis and recombination. Several organisms studied so far, including mammals, worms, yeast and plants achieve these movements by anchoring the chromosome ends to specialized sites in the nuclear envelope (NE). This attachment requires telomere adaptor proteins which have to date been identified in fission yeast and mice. The mouse meiosis-specific telomere adaptor proteins TERB1, TERB2, and MAJIN are involved in the attachment of ubiquitous shelterin telomere to the LINC complex, in an analogous mechanism as those described in fission yeast. Despite the essential role of meiosis-specific telomere adaptor proteins, the precise mechanism of anchorage of telomeres to the nuclear envelope, as well as their evolutionary history, are still not well understood. Therefore, the main aim of this thesis is to investigate the organization of the mouse meiosis-specific telomere adaptor complex TERB1-TERB2-MAJIN and its evolutionary history. In the first part of this thesis high-resolution Structured Illumination Microscopy (SIM), indirect immunofluorescence and Telo-FISH on mouse spermatocytes were used to determine precisely how the telomere complex proteins are localized with relation to the shelterin telomeric TRF1 protein and telomeric DNA. During zygotene and pachytene stages staining patterns revealed extensively overlapping of meiotic telomere complex proteins distributions in which TERB2 organization is more heterogeneous than TERB1 and MAJIN at the chromosome ends. Further, TRF1 localization was shown at the side of lateral elements (LEs) ends with grasp-like distribution surrounding the TERB1 and MAJIN signals in zygotene and pachytene stages. Interestingly, telomeric DNA was shown to be laterally distributed and partially overlapping with the more central distribution displayed by meiotic telomere complex proteins of LEs ends. The combination of these results allowed to describe an alternative model of the telomere attachment to the NE during meiotic prophase I. The second part of this thesis, analyses mouse TERB1, TERB2, and MAJIN evolutionary history. The lack of similarity between mouse and fission yeast meiotic-specific telomere adaptor proteins has raised the question about the origin of this specific complex through evolution. To identify mouse TERB1, TERB2, and MAJIN putative orthologues, computational approaches and phylogenetic analyses were performed. Besides, to test their potential function during meiosis, expression studies were conducted. From these analyses, it was revealed that mouse meiosis-specific telomere complex is ancient, as it originated as early as eumetazoans pointing to a single origin. The absence of any homologs in Nematoda and only a few candidates detected in Arthropoda for meiosis-specific telomere complex, seemed, that these proteins have been lost/replaced or highly diversified in these lineages. Remarkably, TERB1, TERB2, and MAJIN protein domains involved in the formation of the complex as well as those required for the interaction with the telomere shelterin protein and the LINC complexes revealed high sequence similarity across all clades. Finally, gene expression in the cnidarian Hydra Vulgaris provided evidence that the TERB1-TERB2-MAJIN complex is selectively expressed in the germline suggesting conservation of meiotic functions across metazoan evolution. In summary, this thesis provides significant insights into the meiosis-specific telomere complex mechanism to engage telomeres to the nuclear envelope and the elucidation of its origin in metazoans. KW - meiosis KW - chromosomes telomere-led movement KW - TERB1-TERB2-MAJIN KW - SIM KW - Evolution Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-210562 ER - TY - JOUR A1 - Hardulak, Laura A. A1 - Morinière, Jérôme A1 - Hausmann, Axel A1 - Hendrich, Lars A1 - Schmidt, Stefan A1 - Doczkal, Dieter A1 - Müller, Jörg A1 - Hebert, Paul D. N. A1 - Haszprunar, Gerhard T1 - DNA metabarcoding for biodiversity monitoring in a national park: Screening for invasive and pest species JF - Molecular Ecology Resources N2 - DNA metabarcoding was utilized for a large‐scale, multiyear assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal component analysis of read count‐based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of barcode index numbers (BINs) at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger‐sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park. KW - biodiversity KW - DNA barcoding KW - invasive species KW - metabarcoding KW - monitoring KW - pest species Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-217812 VL - 20 IS - 6 SP - 1542 EP - 1557 ER - TY - THES A1 - Cruz Garcia, Yiliam T1 - Interactome of the β2b subunit of L-type voltage-gated calcium channels in cardiomyocytes T1 - Interaktom der β2b-Untereinheit von spannungsgesteuerten L-Typ Kalziumkanälen in Kardiomyozyten N2 - L-type voltage-gated calcium channels (LTCC) are heteromultimeric membrane proteins that allow Ca2+ entry into the cell upon plasma membrane depolarization. The β subunit of voltage-dependent calcium channels (Cavβ) binds to the α-interaction domain in the pore-forming α1 subunit and regulates the trafficking and biophysical properties of these channels. Of the four Cavβ isoforms, Cavβ2 is predominantly expressed in cardiomyocytes. This subunit associates with diverse proteins besides LTCC, but the molecular composition of the Cavβ2 nanoenvironments in cardiomyocytes is yet unresolved. Here, we used a protein-labeling technique in living cells based on an engineered ascorbate peroxidase 2 (APEX2). In this strategy, Cavβ2b was fused to APEX2 and expressed in adult rat cardiomyocytes using an adenovirus system. Nearby proteins covalently labeled with biotin-phenol were purified using streptavidin-coated beads and identified by mass spectrometry (MS). Analysis of the in situ APEX2-based biotin labeling by MS revealed 61 proteins located in the nanoenvironments of Cavβ2b, with a high specificity and consistency in all the replicates. These proteins are involved in diverse cellular functions such as cellular trafficking, sarcomere organization and excitation-contraction coupling. Among these proteins, we demonstrated an interaction between the ryanodine receptor 2 (RyR2) and Cavβ2b, probably coupling LTCC and the RyR2 into a supramolecular complex at the dyads. This interaction is mediated by the Src homology 3 (SH3) domain of Cavβ2b and is necessary for an effective pacing frequency‐dependent increase in Ca2+-induced Ca2+ release in cardiomyocytes. N2 - Die spannungabhängigen L-Typ Kalziumkanäle (LTCC) sind heteromultimere Membranproteine, die den Einstrom von Kalzium (Ca2+) in die Zelle nach Depolarisation der Plasmamembran vermitteln. Die β-Untereinheit von spannungsabhängigen Kalziumkanälen (Cavβ2) bindet an die α-Interaktionsdomäne in der porenformenden α1-Untereinheit und reguliert den Transport und die biophysikalischen Eigenschaften dieser Kanäle. Es gibt vier Isoformen der β-Untereinheiten, die als Cavβ bezeichnet werden, von denen die Cavβ2 Isoform hauptsächlich in Kardiomyozyten exprimiert wird. Diese Untereinheit assoziiert neben dem LTCC mit einer Vielzahl an weiteren Proteinen. Die molekulare Zusammensetzung der Cavβ2 Nanoumgebung, bzw. die Interaktionspartner der Cavβ2 Untereinheit, in Kardiomyozyten ist jedoch immer noch nicht bekannt. In dieser Arbeit verwendeten wir eine Proteinmarkierungstechnik in lebenden Zellen auf Basis einer modifizierten Ascorbatperoxidase 2 (APEX2) um die Cavβ2 Nanoumgebung genauer zu charakterisieren. Dafür wurde Cavβ2b mit APEX2 fusioniert und adenoviral vermittelt in adulten Ratten-Kardiomyozyten exprimiert. APEX2 katalysiert die kovalente Markierung von möglichen Interaktionspartnern in unmittelbarer Nähe der APEX markierten Cavβ2 Untereinheit mit Biotin-Phenol. Markierte Proteine wurden mit Streptavidin beschichteten Beads isoliert und mittels Massenspektrometrie (MS) identifiziert. Die Analyse der MS ergab 61 Proteine in der Nanoumgebung von Cavβ2b. Die Analyse zeichnete sich durch eine hohe Spezifität und Beständigkeit in allen Replikaten aus. Diese identifizierten Proteine haben diverse Funktionen wie zelluläre Transportsteuerung, den Aufbau von Sarkomeren und elektromechanischen Kopplung. Eines dieser Proteinen war der Ryanodinrezeptor 2 (RyR2) und damit konnten wir eine Interaktion von RyR2 und Cavβ2b nachweisen, welche wahrscheinlich die LTCCs und RyR2 zu einem supramolekularen Komplex in den Dyaden verbindet. Diese Interaktion wird durch die Src homology 3 (SH3) Domäne von Cavβ2b vermittelt und ist für einen effektive Stimulationsfrequenz-abhängigen Anstieg der Calcium-induzierten Calciumfreisetzung in Kardiomyozyten notwendig. KW - Calciumkanal KW - Herzmuskelzelle Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208579 ER - TY - JOUR A1 - Vogel, Sebastian A1 - Bussler, Heinz A1 - Finnberg, Sven A1 - Müller, Jörg A1 - Stengel, Elisa A1 - Thorn, Simon T1 - Diversity and conservation of saproxylic beetles in 42 European tree species: an experimental approach using early successional stages of branches JF - Insect Conservation and Diversity N2 - Tree species diversity is important to maintain saproxylic beetle diversity in managed forests. Yet, knowledge about the conservational importance of single tree species and implications for forest management and conservation practices are lacking. We exposed freshly cut branch‐bundles of 42 tree species, representing tree species native and non‐native to Europe, under sun‐exposed and shaded conditions for 1 year. Afterwards, communities of saproxylic beetles were reared ex situ for 2 years. We tested for the impact of tree species and sun exposure on alpha‐, beta‐, and gamma‐diversity as well as composition of saproxylic beetle communities. Furthermore, the number of colonised tree species by each saproxylic beetle species was determined. Tree species had a lower impact on saproxylic beetle communities compared to sun exposure. The diversity of saproxylic beetles varied strongly among tree species, with highest alpha‐ and gamma‐diversity found in Quercus petraea. Red‐listed saproxylic beetle species occurred ubiquitously among tree species. We found distinct differences in the community composition of broadleaved and coniferous tree species, native and non‐native tree species as well as sun‐exposed and shaded deadwood. Our study enhances the understanding of the importance of previously understudied and non‐native tree species for the diversity of saproxylic beetles. To improve conservation practices for saproxylic beetles and especially red‐listed species, we suggest a stronger incorporation of tree species diversity and sun exposure of into forest management strategies, including the enrichment of deadwood from native and with a specific focus on locally rare or silviculturally less important tree species. KW - deadwood KW - deadwood enrichment KW - decay KW - forest management KW - host specificity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218401 VL - 14 IS - 1 SP - 132 EP - 143 ER - TY - JOUR A1 - Leverkus, Alexandro B A1 - Gustafsson, Lena A1 - Lindenmayer, David B A1 - Castro, Jorge A1 - Rey Benayas, José María A1 - Ranius, Thomas A1 - Thorn, Simon T1 - Salvage logging effects on regulating ecosystem services and fuel loads JF - Frontiers in Ecology and the Environment N2 - Salvage logging, or logging after natural disturbances such as wildfires, insect outbreaks, and windstorms, is carried out to recover some of a forest's natural and/or economic capital. However, trade‐offs between management objectives and a lack of consensus on the ecological consequences of salvage logging impair science‐based decision making on the management of forests after natural disturbances. We conducted a global meta‐analysis of the impacts of salvage logging on regulating ecosystem services and on fuel loads, as a frequent post‐disturbance objective is preventing subsequent wildfires that could be fueled by the accumulation of dead trunks and branches. Salvage logging affected ecosystem services in a moderately negative way, regardless of disturbance type and severity, time elapsed since salvage logging, intensity of salvage logging, and the group of regulating ecosystem services being considered. However, prolonging the time between natural disturbance and salvage logging mitigated negative effects on regulating ecosystem services. Salvage logging had no overall effect on surface fuels; rather, different fuel types responded differently depending on the time elapsed since salvage logging. Delaying salvage logging by ~2–4 years may reduce negative ecological impacts without affecting surface fuel loads. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216111 VL - 18 IS - 7 SP - 391 EP - 400 ER - TY - JOUR A1 - Kouhestani, Dina A1 - Geis, Maria A1 - Alsouri, Saed A1 - Bumm, Thomas G. P. A1 - Einsele, Hermann A1 - Sauer, Markus A1 - Stuhler, Gernot T1 - Variant signaling topology at the cancer cell–T-cell interface induced by a two-component T-cell engager JF - Cellular & Molecular Immunology N2 - No abstract available. KW - immunotherapy KW - tumour immunology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241189 VL - 18 ER - TY - JOUR A1 - Hensgen, Ronja A1 - England, Laura A1 - Homberg, Uwe A1 - Pfeiffer, Keram T1 - Neuroarchitecture of the central complex in the brain of the honeybee: Neuronal cell types JF - Journal of Comparative Neurology N2 - The central complex (CX) in the insect brain is a higher order integration center that controls a number of behaviors, most prominently goal directed locomotion. The CX comprises the protocerebral bridge (PB), the upper division of the central body (CBU), the lower division of the central body (CBL), and the paired noduli (NO). Although spatial orientation has been extensively studied in honeybees at the behavioral level, most electrophysiological and anatomical analyses have been carried out in other insect species, leaving the morphology and physiology of neurons that constitute the CX in the honeybee mostly enigmatic. The goal of this study was to morphologically identify neuronal cell types of the CX in the honeybee Apis mellifera. By performing iontophoretic dye injections into the CX, we traced 16 subtypes of neuron that connect a subdivision of the CX with other regions in the bee's central brain, and eight subtypes that mainly interconnect different subdivisions of the CX. They establish extensive connections between the CX and the lateral complex, the superior protocerebrum and the posterior protocerebrum. Characterized neuron classes and subtypes are morphologically similar to those described in other insects, suggesting considerable conservation in the neural network relevant for orientation. KW - RRID: AB_2337244 KW - RRID: AB_2315425 KW - central complex KW - insect brain KW - neuroanatomy KW - sky compass KW - Apis mellifera Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215566 VL - 529 ER - TY - JOUR A1 - Anton, Sylvia A1 - Rössler, Wolfgang T1 - Plasticity and modulation of olfactory circuits in insects JF - Cell and Tissue Research N2 - Olfactory circuits change structurally and physiologically during development and adult life. This allows insects to respond to olfactory cues in an appropriate and adaptive way according to their physiological and behavioral state, and to adapt to their specific abiotic and biotic natural environment. We highlight here findings on olfactory plasticity and modulation in various model and non-model insects with an emphasis on moths and social Hymenoptera. Different categories of plasticity occur in the olfactory systems of insects. One type relates to the reproductive or feeding state, as well as to adult age. Another type of plasticity is context-dependent and includes influences of the immediate sensory and abiotic environment, but also environmental conditions during postembryonic development, periods of adult behavioral maturation, and short- and long-term sensory experience. Finally, plasticity in olfactory circuits is linked to associative learning and memory formation. The vast majority of the available literature summarized here deals with plasticity in primary and secondary olfactory brain centers, but also peripheral modulation is treated. The described molecular, physiological, and structural neuronal changes occur under the influence of neuromodulators such as biogenic amines, neuropeptides, and hormones, but the mechanisms through which they act are only beginning to be analyzed. KW - antenna KW - antennal lobe KW - mushroom body KW - neuromodulation KW - structural synaptic plasticity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235820 SN - 0302-766X VL - 383 ER - TY - JOUR A1 - Bohnert, Simone A1 - Reinert, Christoph A1 - Trella, Stefanie A1 - Schmitz, Werner A1 - Ondruschka, Benjamin A1 - Bohnert, Michael T1 - Metabolomics in postmortem cerebrospinal fluid diagnostics: a state-of-the-art method to interpret central nervous system–related pathological processes JF - International Journal of Legal Medicine N2 - In the last few years, quantitative analysis of metabolites in body fluids using LC/MS has become an established method in laboratory medicine and toxicology. By preparing metabolite profiles in biological specimens, we are able to understand pathophysiological mechanisms at the biochemical and thus the functional level. An innovative investigative method, which has not yet been used widely in the forensic context, is to use the clinical application of metabolomics. In a metabolomic analysis of 41 samples of postmortem cerebrospinal fluid (CSF) samples divided into cohorts of four different causes of death, namely, cardiovascular fatalities, isoIated torso trauma, traumatic brain injury, and multi-organ failure, we were able to identify relevant differences in the metabolite profile between these individual groups. According to this preliminary assessment, we assume that information on biochemical processes is not gained by differences in the concentration of individual metabolites in CSF, but by a combination of differently distributed metabolites forming the perspective of a new generation of biomarkers for diagnosing (fatal) TBI and associated neuropathological changes in the CNS using CSF samples. KW - CSF KW - cerebrospinal fluid KW - forensic neuropathology KW - forensic neurotraumatology KW - biomarker KW - metabolomics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235724 SN - 0937-9827 VL - 135 ER - TY - JOUR A1 - Boff, Samuel A1 - Henrique, Jessica Amaral A1 - Friedel, Anna A1 - Raizer, Josué T1 - Disentangling the path of pollinator attraction in temporarily colored flowers JF - International Journal of Tropical Insect Science N2 - Plants may use different strategies to attract pollinators in long distance (e.g. floral display) and in short distance (e.g. ratio between differentially colored flowers) scales. The Verbenaceae Lantana canescens Kunth is a wide spread species in open sites of the Brazilian Pantanal wetland. Individuals of this generalist species can produce a variable number of open inflorescences with yellow and white flowers that are organized in whorls. In this study we tested the hypothesis that increased floral display (long distance attraction) and the ratio between yellow and white flowers (short distance attraction) enhances the number of pollinator species and individuals. We observed flower visitors and calculated floral parameters in 38 plots of 1 m2 each, that contained a varying number of flowering L. canescens individuals. Non-metric multidimensional scaling and Bray-Curtis distances were used to account for flower visitor composition and the relative visitation rate, respectively. We used a structural equation model to test the power of each predictor variable on the visitation rate and a covariance analysis to disentangle the effect of each independent variable on the frequency of plant-pollinator interactions. We found that the number of flower visitors and the visitation rate increased with increasing number of inflorescences. Disentangling long and short distance attraction indicated that the number of inflorescences (per plot) and the number of yellow flowers (yellowing effect) contributed most to flower visitation at long and short distance, respectively. KW - floral display KW - lantana canescens KW - pantanal wetland KW - honey bees KW - neotropical region KW - pollinator attraction Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235402 VL - 41 ER - TY - JOUR A1 - Jessen, Christina A1 - Kreß, Julia K. C. A1 - Baluapuri, Apoorva A1 - Hufnagel, Anita A1 - Schmitz, Werner A1 - Kneitz, Susanne A1 - Roth, Sabine A1 - Marquardt, André A1 - Appenzeller, Silke A1 - Ade, Casten P. A1 - Glutsch, Valerie A1 - Wobser, Marion A1 - Friedmann-Angeli, José Pedro A1 - Mosteo, Laura A1 - Goding, Colin R. A1 - Schilling, Bastian A1 - Geissinger, Eva A1 - Wolf, Elmar A1 - Meierjohann, Svenja T1 - The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression JF - Oncogene N2 - The transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H\(_2\)O\(_2\) or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma. KW - NRF2 KW - melanoma malignancy KW - COX2 expression Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235064 SN - 0950-9232 VL - 39 ER - TY - INPR A1 - Dandekar, Thomas T1 - Our universe may have started by Qubit decoherence N2 - Our universe may have started by Qubit decoherence: In quantum computers, qubits have all their states undefined during calculation and become defined as output (“decoherence”). We study the transition from an uncontrolled, chaotic quantum vacuum (“before”) to a clearly interacting “real world”. In such a cosmology, the Big Bang singularity is replaced by a condensation event of interacting strings. This triggers a crystallization process. This avoids inflation, not fitting current observations: increasing long-range interactions limit growth and crystal symmetries ensure the same laws of nature and basic symmetries over the whole crystal. Tiny mis-arrangements provide nuclei of superclusters and galaxies and crystal structure allows arrangement of dark (halo regions) and normal matter (galaxy nuclei) for galaxy formation. Crystals come and go: an evolutionary cosmology is explored: entropic forces from the quantum soup “outside” of the crystal try to dissolve it. This corresponds to dark energy and leads to a “big rip” in 70 Gigayears. Selection for best growth and condensation events over generations of crystals favors multiple self-organizing processes within the crystal including life or even conscious observers in our universe. Philosophically this theory shows harmony with nature and replaces absurd perspectives of current cosmology. Independent of cosmology, we suggest that a “real world” (so our everyday macroscopic world) happens only inside a crystal. “Outside” there is wild quantum foam and superposition of all possibilities. In our crystallized world the vacuum no longer boils but is cooled down by the crystallization event, space-time exists and general relativity holds. Vacuum energy becomes 10**20 smaller, exactly as observed in our everyday world. We live in a “solid” state, within a crystal, the n quanta which build our world have all their different m states nicely separated. There are only nm states available for this local “multiverse”. The arrow of entropy for each edge of the crystal forms one fate, one world-line or clear development of our world, while layers of the crystal are different system states. Mathematical leads from loop quantum gravity (LQG) point to required interactions and potentials. Interaction potentials for strings or loop quanta of any dimension allow a solid, decoherent state of quanta challenging to calculate. However, if we introduce here the heuristic that any type of physical interaction of strings corresponds just to a type of calculation, there is already since 1898 the Hurwitz theorem showing that then only 1D, 2D, 4D and 8D (octonions) allow complex or hypercomplex number calculations. No other hypercomplex numbers and hence dimensions or symmetries are possible to allow calculations without yielding divisions by zero. However, the richest solution allowed by the Hurwitz theorem, octonions, is actually the observed symmetry of our universe, E8. Standard physics such as condensation, crystallization and magnetization but also solid-state physics and quantum computing allow us to show an initial mathematical treatment of our new theory by LQG to describe the cosmological state transformations by equations, and, most importantly, point out routes to parametrization of free parameters looking at testable phenomena, experiments and formulas that describe processes of crystallization, protein folding, magnetization, solid-state physics and quantum computing. This is presented here for LQG, for string theory it would be more elegant but was too demanding to be shown here. Note: While my previous Opus server preprint “A new cosmology of a crystallization process (decoherence) from the surrounding quantum soup provides heuristics to unify general relativity and quantum physics by solid state physics” (https://doi.org/10.25972/OPUS-23076) deals with the same topics and basic formulas, this new version is improved: clearer in title, better introduction, more stringent in its mathematics and improved discussion of the implications including quantum computing, hints for parametrization and connections to LQG and other current cosmological efforts. This 5th of June 2021 version is again an OPUS preprint, but this will next be edited for Archives https://arxiv.org. KW - cosmology KW - quantum computing KW - loop quantum gravity KW - qubit KW - decoherence KW - crystallization Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239181 ER - TY - THES A1 - Mayr, Antonia Veronika T1 - Following Bees and Wasps up Mt. Kilimanjaro: From Diversity and Traits to hidden Interactions of Species T1 - Auf den Spuren von Bienen und Wespen auf den Kilimandscharo: Eine Studie über die Diversität, Merkmale und verborgenen Wechselwirkungen zwischen Arten N2 - Chapter 1 – General Introduction One of the greatest challenges of ecological research is to predict the response of ecosystems to global change; that is to changes in climate and land use. A complex question in this context is how changing environmental conditions affect ecosystem processes at different levels of communities. To shed light on this issue, I investigate drivers of biodiversity on the level of species richness, functional traits and species interactions in cavity-nesting Hymenoptera. For this purpose, I take advantage of the steep elevational gradient of Mt. Kilimanjaro that shows strong environmental changes on a relatively small spatial scale and thus, provides a good environmental scenario for investigating drivers of diversity. In this thesis, I focus on 1) drivers of species richness at different trophic levels (Chapter 2); 2) seasonal patterns in nest-building activity, life-history traits and ecological rates in three different functional groups and at different elevations (Chapter 3) and 3) changes in cuticular hydrocarbons, pollen composition and microbiomes in Lasioglossum bees caused by climatic variables (Chapter 4). Chapter 2 – Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera Drivers of species richness have been subject to research for centuries. Temperature, resource availability and top-down regulation as well as the impact of land use are considered to be important factors in determining insect diversity. Yet, the relative importance of each of these factors is unknown. Using trap nests along the elevational gradient of Mt. Kilimanjaro, we tried to disentangle drivers of species richness at different trophic levels. Temperature was the major driver of species richness across trophic levels, with increasing importance of food resources at higher trophic levels in natural antagonists. Parasitism rate was both related to temperature and trophic level, indicating that the relative importance of bottom-up and top-down forces might shift with climate change. Chapter 3 – Seasonal variation in the ecology of tropical cavity-nesting Hymenoptera Natural populations fluctuate with the availability of resources, presence of natural enemies and climatic variations. But tropical mountain seasonality is not yet well investigated. We investigated seasonal patterns in nest-building activity, functional traits and ecological rates in three different insect groups at lower and higher elevations separately. Insects were caught with trap nests which were checked monthly during a 17 months period that included three dry and three rainy seasons. Insects were grouped according to their functional guilds. All groups showed strong seasonality in nest-building activity which was higher and more synchronised among groups at lower elevations. Seasonality in nest building activity of caterpillar-hunting and spider-hunting wasps was linked to climate seasonality while in bees it was strongly linked to the availability of flowers, as well as for the survival rate and sex ratio of bees. Finding adaptations to environmental seasonality might imply that further changes in climatic seasonality by climate change could have an influence on life-history traits of tropical mountain species. Chapter 4 – Cryptic species and hidden ecological interactions of halictine bees along an elevational Gradient Strong environmental gradients such as those occurring along mountain slopes are challenging for species. In this context, hidden adaptations or interactions have rarely been considered. We used bees of the genus Lasioglossum as model organisms because Lasioglossum is the only bee genus occurring with a distribution across the entire elevational gradient at Mt. Kilimanjaro. We asked if and how (a) cuticular hydrocarbons (CHC), which act as a desiccation barrier, change in composition and chain length along with changes in temperature and humidity (b), Lasioglossum bees change their pollen diet with changing resource availability, (c) gut microbiota change with pollen diet and climatic conditions, and surface microbiota change with CHC and climatic conditions, respectively, and if changes are rather influenced by turnover in Lasioglossum species along the elevational gradient. We found physiological adaptations with climate in CHC as well as changes in communities with regard to pollen diet and microbiota, which also correlated with each other. These results suggest that complex interactions and feedbacks among abiotic and biotic conditions determine the species composition in a community. Chapter 5 – General Discussion Abiotic and biotic factors drove species diversity, traits and interactions and they worked differently depending on the functional group that has been studied, and whether spatial or temporal units were considered. It is therefore likely, that in the light of global change, different species, traits and interactions will be affected differently. Furthermore, increasing land use intensity could have additional or interacting effects with climate change on biodiversity, even though the potential land-use effects at Mt. Kilimanjaro are still low and not impairing cavity-nesting Hymenoptera so far. Further studies should address species networks which might reveal more sensitive changes. For that purpose, trap nests provide a good model system to investigate effects of global change on multiple trophic levels and may also reveal direct effects of climate change on entire life-history traits when established under different microclimatic conditions. The non-uniform effects of abiotic and biotic conditions on multiple aspects of biodiversity revealed with this study also highlight that evaluating different aspects of biodiversity can give a more comprehensive picture than single observations. N2 - Kapitel 1 – Allgemeine Einführung Eine der größten Herausforderungen der ökologischen Forschung ist es, die Reaktion der Ökosysteme auf den globalen Wandel, d.h. auf Veränderungen von Klima und Landnutzung, vorherzusagen. Eine komplexe Frage in diesem Zusammenhang ist, wie sich verändernde Umweltbedingungen auf die Ökosystemprozesse auf verschiedenen Ebenen von Gemeinschaften auswirken. Um dieses Thema näher zu beleuchten, untersuche ich die Triebkräfte der Biodiversität auf der Ebene des Artenreichtums, der funktionellen Eigenschaften und der Wechselwirkungen zwischen Arten bei Hautflüglern, die in Hohlräumen nisten. Zu diesem Zweck nutze ich den steilen Höhengradienten des Kilimandscharo, der starke Umweltveränderungen auf relativ kleinem Raum mit sich bringt und somit ein gutes System für die Untersuchung von Triebkräften der biologischen Vielfalt bietet. In dieser Arbeit konzentriere ich mich auf 1) Triebkräfte des Artenreichtums auf verschiedenen trophischen Ebenen (Kapitel 2); 2) saisonale Muster in der Nestbauaktivität, lebensgeschichtliche Merkmale und ökologische Raten in drei verschiedenen funktionellen Gruppen und in verschiedenen Höhenlagen (Kapitel 3) und 3) Veränderungen in kutikulären Kohlenwasserstoffen, Pollenzusammensetzung und Mikrobiomen bei Lasioglossum Bienen, die durch klimatische Faktoren verursacht werden (Kapitel 4). Kapitel 2 – Klima und Nahrungsressourcen prägen den Artenreichtum und die trophischen Wechselwirkungen von hohlraumnistenden Hautflüglern Die Triebkräfte des Artenreichtums werden seit Jahrhunderten erforscht. Temperatur, Ressourcenverfügbarkeit und Top-Down-Regulierung sowie die Auswirkungen der Landnutzung werden als wichtige Faktoren für die Bestimmung der Insektenvielfalt angesehen. Die relative Bedeutung jedes dieser Faktoren ist jedoch unbekannt. Mit Hilfe von Nisthilfen entlang des Höhengradienten des Kilimandscharo versuchten wir, die Triebkräfte des Artenreichtums auf verschiedenen trophischen Ebenen zu enträtseln. Die Temperatur war der Hauptfaktor für den Artenreichtum auf allen trophischen Ebenen, wobei die Bedeutung der Nahrungsressourcen auf den höheren trophischen Ebenen der natürlichen Antagonisten zunahm. Die Parasitierungsrate wurde sowohl durch die Temperatur als auch durch die trophische Ebene bestimmt, was darauf hindeutet, dass sich die relative Bedeutung der Bottom-up- und Top-down-Kräfte mit dem Klimawandel verschieben könnte. Kapitel 3 – Saisonale Schwankungen in der Ökologie von tropischen hohlraumnistenden Hautflüglern Natürliche Populationen schwanken mit der Verfügbarkeit von Ressourcen, dem Vorhandensein natürlicher Feinde und klimatischen Schwankungen. Die Saisonalität ist jedoch auf tropischen Bergen noch nicht gut untersucht. Wir untersuchten saisonale Muster in der Nestbauaktivität, funktionale Merkmale und ökologische Raten bei drei verschiedenen Insektengruppen in niedrigeren und höheren Höhenlagen. Insekten wurden mit Nisthilfen gefangen, die während eines Zeitraums von 17 Monaten, der drei Trocken- und drei Regenzeiten umfasste, monatlich überprüft wurden. Die Insekten wurden nach ihren funktionalen Gilden eingeteilt. Alle Gruppen zeigten eine starke Saisonalität im Nestbau, die in niedrigeren Lagen höher war und dort zwischen den Gruppen stärker synchronisiert war. Die Saisonalität im Nestbau von Raupen- und Spinnen- jagenden Wespen war mit saisonalen Klimaschwankungen verbunden, während sie bei Bienen stark von der Verfügbarkeit von Blüten abhing, genauso wie die Überlebensrate und das Geschlechterverhältnis der Bienen von der Blütenmenge abhing. Die Anpassung an die Saisonalität der Umwelt könnte bedeuten, dass weitere Veränderungen der saisonalen Klimaschwankungen durch den Klimawandel einen Einfluss auf die lebensgeschichtlichen Merkmale tropischer Bergarten haben könnten. Kapitel 4 – Kryptische Arten und versteckte ökologische Wechselwirkungen bei Schmalbienen entlang eines Höhengradienten Starke Umweltgradienten, wie sie an Berghängen auftreten, stellen für Arten eine Herausforderung dar. Versteckte Anpassungen oder Interaktionen wurden in diesem Zusammenhang selten berücksichtigt. Als Modellorganismen haben wir Bienen der Gattung Lasioglossum verwendet, da Lasioglossum die einzige Bienengattung ist, die über den gesamten Höhengradienten am Kilimandscharo weit verbreitet ist. Wir fragten, ob und wie (a) kutikuläre Kohlenwasserstoffe (CHC), die als Barriere gegen Austrocknung wirken, sich in ihrer Zusammensetzung und Kettenlänge entlang von Temperatur- und Feuchtigkeitsänderungen verändern; (b) Lasioglossum Bienen ihre Pollennahrung mit wechselnder Ressourcenverfügbarkeit ändern; (c) Änderungen von Darm-Mikrobiota mit Pollennahrung und Klimabedingungen und Änderungen von Oberflächen-Mikrobiota mit CHC und Klimabedingungen zusammen hängen, und ob die Veränderungen eher durch den Wechsel von Lasioglossum Arten entlang des Höhengradienten beeinflusst werden. Wir fanden physiologische Anpassungen an das Klima in CHC, sowie Veränderungen in der Zusammensetzung von Pollennahrung und Mikrobiota, die auch miteinander korrelierten. Diese Ergebnisse deuten darauf hin, dass komplexe Wechselwirkungen und Rückkopplungen zwischen abiotischen und biotischen Bedingungen die Artenzusammensetzung in einer Gemeinschaft bestimmen. Kapitel 5 – Allgemeine Diskussion Abiotische und biotische Faktoren förderten die Artenvielfalt, Eigenschaften und Wechselwirkungen von Arten und sie wirkten unterschiedlich, je nachdem, welche funktionelle Gruppe untersucht wurde und ob räumliche oder zeitliche Einheiten berücksichtigt worden sind. Es ist daher wahrscheinlich, dass im Lichte des globalen Wandels verschiedene Arten, Merkmale und Wechselwirkungen unterschiedlich betroffen sein werden. Darüber hinaus könnte eine zunehmende Landnutzungsintensität zusätzliche Auswirkungen oder Wechselwirkungen mit dem Klimawandel auf die Biodiversität haben, auch wenn die potenziellen Landnutzungseffekte am Kilimandscharo noch gering sind und bis jetzt die hohlraumnistenden Hautflüglern nicht beeinträchtigen. Weitere Studien sollten sich mit Nahrungsnetzwerken befassen, die empfindlichere Veränderungen aufzeigen könnten. Nisthilfen bieten dafür ein gutes Modellsystem, um die Auswirkungen des globalen Wandels auf mehreren trophischen Ebenen zu untersuchen, und können auch direkte Auswirkungen des Klimawandels auf ganze lebensgeschichtliche Merkmale aufzeigen, wenn sie unter verschiedenen mikroklimatischen Bedingungen etabliert werden. Die nicht einheitlichen Auswirkungen abiotischer und biotischer Bedingungen auf mehrere Aspekte der Biodiversität, die in dieser Studie gezeigt wurden, zeigen auch, dass die Untersuchung verschiedener Aspekte der Biodiversität ein umfassenderes Bild vermitteln kann als Einzelbetrachtungen. KW - land use KW - Landnutzung KW - climate change KW - bees KW - wasps KW - biodiversity KW - Klimawandel KW - Bienen KW - Wespen KW - Biodiversität Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-182922 ER - TY - THES A1 - Krimmer, Elena T1 - Agri-environment schemes and ecosystem services: The influence of different sown flower field characteristics on pollination, natural pest control and crop yield T1 - Agrarumweltmaßnahmen und Ökosystemdienstleistungen: der Einfluss unterschiedlicher Blühflächen Merkmale auf Bestäubung, natürliche Schädlingskontrolle und Erträge N2 - Insects are responsible for the major part of the ecosystem services pollination and natural pest control. If insects decline, these ecosystem services can not longer be reliably delivered. Agricultural intensification and the subsequent loss and fragmentation of habitats has among others been identified to cause insect decline. Ecological intensification aims to promote alternative and sustainable management practices in agricultural farming, for example to decrease the use of external inputs such as pesticides. Agri-environment schemes make amends for farmers if they integrate ecologically beneficial measures into their farming regime and can therefore promote ecological intensification. There is a wide variety of agri-environment schemes, but the implementation of sown flower fields on crop fields is often included. Flower fields offer foraging resources as well as nesting sites for many different insect species and should be able to support insect populations as well as to increase ecosystem services to adjacent fields. However, the potential of flower fields to exhibit these effects is depending on many factors. Among others, the age and size of the flower field can influence if and how different insects profit from the measure. Additionally, the complexity of the surrounding landscape and therefore the existing biodiversity is influencing the potential of flower fields to increase ecosystem services locally. The goal of this study is to disentangle to which degree these factors influence the ecosystem services pollination and natural pest control and if these factors interact with each other. Furthermore, it will be examined if and how flower fields and ecosystem services influence crop yield. Additional factors examined in this study are distance decay and pesticide use. The abundance of beneficial insects can decrease strongly with increasing distance to suitable habitats. Pesticide use in turn could abrogate positive effects of flower fields on beneficial insects. To examine these different aspects and to be able to make recommendations for flower field implementation, field experiments were conducted on differently composed sown flower fields and adjacent oilseed rape fields. Flower fields differed in their age and continuity as well as in their size. Additionally, flower and oilseed rape fields were chosen in landscapes with different amounts of semi-natural habitat. Oilseed rape fields adjacent to calcareous grasslands and conventional crop fields served as controls. Pollinator observations and pollen beetle and parasitism surveys were conducted in the oilseed rape fields. Additionally, different yield parameters of the oilseed rape plants were recorded. Observations were conducted and samples taken in increasing distance to the flower fields to examine distance decay functions. Spray windows were established to inspect the influence of pesticides on ecosystem services and crop yields. Linear mixed models were used for statistical analysis. The results show, that newly established flower fields with high amounts of flower cover are very attractive for pollinators. If the flower fields reached a certain size (> 1.5ha), the pollinators tended to stay in these fields and did not distribute into the surroundings. High amounts of semi-natural habitat in the surrounding landscape increased the value of small flower fields as starting points for pollinators and their subsequent spillover into crop fields. Additionally, high amounts of semi-natural habitat decreased the decay of pollinators with increasing distance to the flower fields. Based on these results, it can be recommended to establish many small flower fields in landscapes with high amounts of semi-natural habitat and large flower fields in landscapes with low amounts of semi-natural habitat. However, it is mentionable that flower fields are no substitute for perennial semi-natural habitats. These still must be actively conserved to increase pollination to crop fields. Furthermore, the lowest amount of pollen beetle infestation was found on oilseed rape fields adjacent to continuous flower fields aged older than 6 years. Flower fields and calcareous grasslands in general increased pollen beetle parasitism in adjacent oilseed rape fields compared to conventional crop fields. The threshold for effective natural pest control could only be reached in the pesticide free areas in the oilseed rape fields adjacent to continuous flower fields and calcareous grasslands. Parasitism and superparasitism declined with increasing distance to the adjacent fields in pesticide treated areas of the oilseed rape fields. However, they remained on a similar level in spray windows without pesticides. Large flower fields increased parasitism and superparasitism more than small flower fields. Flower fields generally have the potential to increase pollen beetle parasitism rates, but pesticides can abrogate these positive effects of flower fields on natural pest control. Last but not least, effects of flower fields and ecosystem services on oilseed rape yield were examined. No positive effects of pollination on oilseed rape yield could be found. Old and continuous flower fields increased natural pest control in oilseed rape fields, which in turn increased seed set and total seed weight of oilseed rape plants. The pesticide treatment had negative effects on natural pest control, but positive effects on crop yield. Pollination and natural pest control decreased with increasing distance to the field edge, but fruit set slightly increased. The quality of the field in terms of soil and climatic conditions did not influence the yield parameters examined in this study. Yield formation in oilseed rape plants is a complex process with many factors involved, and it is difficult to disentangle indirect effects of flower fields on yield. However, perennial flower fields can promote ecological intensification by increasing crop yield via natural pest control. This study contributes to a better understanding of the effects of differently composed flower fields on pollination, natural pest control and oilseed rape yield. N2 - Insekten sind für einen Großteil der Ökosystemdienstleistungen Bestäubung und natürliche Schädlingskontrolle zuständig. Schwinden die Insekten, so können diese Dienstleistungen nicht mehr zuverlässig gewährleistet werden. Als Ursachen für den Rückgang an Insekten wurde unter anderem die Intensivierung der Landwirtschaft und damit einhergehend der Verlust und die Fragmentierung von Lebensraum identifiziert. Ökologische Intensivierung hat das Ziel, alternative und nachhaltige Bewirtschaftungsmethoden in der Landwirtschaft zu fördern und beispielsweise den Einsatz von Spritzmitteln zu verringern. Agrarumweltmaßnahmen entschädigen Landwirte, wenn sie ökologisch wertvolle Maßnahmen in ihren Betrieb integrieren und können dadurch ökologische Intensivierung unterstützen. Die Bandbreite an Agrarumweltmaßnahmen ist groß, beinhaltet aber häufig das Anlegen von Blühflächen auf Ackerflächen. Blühflächen liefern Nahrungsressourcen und Lebensraum für eine Vielzahl von Insekten und sollten daher in der Lage sein Insektenpopulationen zu unterstützen und Ökosystemdienstleistungen auf angrenzenden Feldern zu verstärken. Jedoch ist das ökologische Potential von Blühflächen von einer Vielzahl von Faktoren abhängig. Unter anderem können das Alter und die Größe der Blühfläche entscheidend beeinflussen, inwiefern unterschiedliche Insektengruppen profitieren. Zusätzlich hat die Landschaftskomplexität der direkten Umgebung, und damit die potentiell vorhandene Biodiversität, großen Einfluss auf die Fähigkeit von Blühflächen Ökosystemdienstleistungen lokal zu erhöhen. In dieser Studie geht es darum zu entschlüsseln, wie sich diese verschiedenen Faktoren sich auf die beiden Ökosystemdienstleistungen Bestäubung und natürliche Schädlingskontrolle auswirken und ob sie sich gegenseitig beeinflussen. Zusätzlich soll untersucht werden, inwiefern Blühflächen und Ökosystemdienstleistungen Erträge beeinflussen können. Weitere in dieser Studie untersuchte Einflussfaktoren sind die Distanz zur Blühfläche und der Einsatz von Pestiziden. Die Abundanz von Nützlingen kann mit der Distanz zu geeigneten Habitaten stark abnehmen. Der Einsatz von Spritzmitteln wiederum könnte die positiven Einflüsse der Blühflächen auf Nützlinge aufheben. Um diese verschiedenen Aspekte zu untersuchen und letztendlich Empfehlung für die Etablierung von Blühflächen geben zu können, wurden Feldversuche auf Blühflächen mit unterschiedlicher Beschaffenheit und auf angrenzenden Rapsflächen durchgeführt. Die Blühflächen unterschieden sich hierbei in ihrem Alter und ihrer Kontinuität. Zusätzlich wurden Blühflächen mit unterschiedlicher Größe getestet. Außerdem wurden die Blühflächen und ihre benachbarten Rapsfelder so ausgewählt, dass sie sich in Landschaften mit unterschiedlichem Anteil an halbnatürlichen Habitaten befinden. Rapsflächen neben Kalkmagerrasen und Äckern mit konventionellen Feldfrüchten dienten als Kontrollflächen. Auf den Rapsflächen wurden Bestäuberbeobachtungen sowie Aufnahmen von Rapsglanzkäferbefall und deren Parasitierung durchgeführt. Zusätzlich wurden verschiedene Ertragsparameter von Raps aufgenommen. Die Untersuchungen fanden jeweils in unterschiedlichen Distanzen zur Blühfläche innerhalb des Rapsfeldes statt, um Distanz-Abnahme Funktionen zu untersuchen. Spritzfenster wurden etabliert, um den Einfluss von Pestiziden auf Ökosystemdienstleistungen und Erträge zu untersuchen. Für die statistische Auswertung wurden lineare gemischte Modelle verwendet. Die Ergebnisse haben zum einen gezeigt, dass frisch angelegte Blühflächen mit hoher Blütendeckung sehr attraktiv für Bestäuber sind. Jedoch blieben die Bestäuber in den Blühflächen, wenn diese eine gewisse Größe hatten (> 1.5ha) und verteilten sich nicht auf die umgebenden Flächen. Ein hoher Anteil an halbnatürlichen Habitaten in der umgebenden Landschaft erhöhte den Wert von kleinen Blühflächen als Ausgangspunkt für Bestäuber und ihren anschließenden Übergang auf Ackerflächen. Hohe Mengen an halbnatürlichen Habitaten verringerten außerdem den Rückgang der Bestäuber mit steigender Entfernung zur Blühfläche. Auf Grundlage dieser Ergenisse wäre es zu empfehlen, kleine Blühflächen in Landschaften mit viel halbnatürlichem Habitat und große Blühflächen in Landschaften mit wenig halbnatürlichem Habitat anzulegen. Außerdem ist anzumerken, dass Blühflächen keinen adequaten Ersatz für dauerhafte halbantürliche Habitate darstellen. Diese müssen weiterhin aktiv geschützt und erhalten werden, um Bestäubung auf Ackerflächen zu fördern. Des Weiteren wurde auf Rapsflächen neben kontinuierlichen Blühflächen mit einem Alter über 6 Jahre der niedrigste Befall mit Rapsglanzkäferlarven festgestellt. Blühflächen und Kalkmagerrasen erhöhten die Parasitierung von Rapsglanzkäfern in benachbarten Rapsflächen im Vergleich zu Rapsflächen die neben Ackerflächen liegen. Der Schwellenwert für eine effektive natürliche Schädlingskontrolle wurde nur in den pestizidfreien Bereichen in Rapsflächen neben kontinuierlichen Blühflächen und Kalkmagerasen erreicht. In mit Pestiziden behandelten Bereichen nahmen Parasitismus und Superparasitismus mit zunehmender Entfernung zum benachbarten Feld ab. In den Spritzfenstern ohne Pestizide blieben sie jedoch auf dem gleichen Niveau. Große Blühflächen erhöhten Parasitismus und Superparasitismus mehr als kleine. Insgesamt können Blühflächen die Parasitierungsraten von Rapsglanzkäfern auf Rapsflächen erhöhen, jedoch können Pestizide diese positiven Effekte aufheben. Zuletzt wurden die Effekte von Blühflächen und Ökosystemdienstleistungen auf den Rapsertrag untersucht. Hier stellte sich heraus, dass Bestäubung keine positiven Effekte auf den Rapsertrag hatte. Alte und kontinuierliche Blühflächen erhöhten die natürliche Schädlingskontrolle in den Rapsfeldern, welche wiederrum den Samenansatz und das absolute Samengewicht erhöhten. Die Behandlung mit Pestiziden hatte negative Asuwirkungen auf natürliche Schädlingskontrolle, aber positive Auswirkungen auf den Ertrag. Bestäubung und natürliche Schädlingskontrolle nahmen mit der zunehmenden Entfernung zum Feldrand ab, aber der Fruchtansatz nahm leicht zu. Die Feldqualität hatte keine Auswirkungen auf die im Modell untersuchten Rapsertrag Messwerte. Ertragsbildung bei Rapspflanzen ist ein komplexer Vorgang an dem viele Faktoren beteiligt sind. Mehrjährige Blühflächen können ökologische Intensivierung fördern indem sie den Ertrag durch natürliche Schädlingskontrolle erhöhen. Diese Studie leistet einen wertvollen Beitrag zum besseren Verständnis der Auswirkungen von unterschiedlich beschaffenen Blühflächen auf Bestäubung, natürliche Schädlingskontrolle und Rapsertrag. KW - Ökologie KW - Agrarumweltmaßnahmen KW - Ökosystemdienstleistung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206577 ER - TY - JOUR A1 - Wu, Yu A1 - Pons, Valérie A1 - Goudet, Amélie A1 - Panigai, Laetitia A1 - Fischer, Annette A1 - Herweg, Jo-Ana A1 - Kali, Sabrina A1 - Davey, Robert A. A1 - Laporte, Jérôme A1 - Bouclier, Céline A1 - Yousfi, Rahima A1 - Aubenque, Céline A1 - Merer, Goulven A1 - Gobbo, Emilie A1 - Lopez, Roman A1 - Gillet, Cynthia A1 - Cojean, Sandrine A1 - Popoff, Michel R. A1 - Clayette, Pascal A1 - Le Grand, Roger A1 - Boulogne, Claire A1 - Tordo, Noël A1 - Lemichez, Emmanuel A1 - Loiseau, Philippe M. A1 - Rudel, Thomas A1 - Sauvaire, Didier A1 - Cintrat, Jean-Christophe A1 - Gillet, Daniel A1 - Barbier, Julien T1 - ABMA, a small molecule that inhibits intracellular toxins and pathogens by interfering with late endosomal compartments JF - Scientific Reports N2 - Intracellular pathogenic microorganisms and toxins exploit host cell mechanisms to enter, exert their deleterious effects as well as hijack host nutrition for their development. A potential approach to treat multiple pathogen infections and that should not induce drug resistance is the use of small molecules that target host components. We identifed the compound 1-adamantyl (5-bromo-2-methoxybenzyl) amine (ABMA) from a cell-based high throughput screening for its capacity to protect human cells and mice against ricin toxin without toxicity. This compound efciently protects cells against various toxins and pathogens including viruses, intracellular bacteria and parasite. ABMA provokes Rab7-positive late endosomal compartment accumulation in mammalian cells without affecting other organelles (early endosomes, lysosomes, the Golgi apparatus, the endoplasmic reticulum or the nucleus). As the mechanism of action of ABMA is restricted to host-endosomal compartments, it reduces cell infection by pathogens that depend on this pathway to invade cells. ABMA may represent a novel class of broad-spectrum compounds with therapeutic potential against diverse severe infectious diseases. KW - biology KW - antimicrobials KW - high-throughput screening KW - infectious diseases Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173170 VL - 7 ER - TY - JOUR A1 - Lukeš, Tomáš A1 - Glatzová, Daniela A1 - Kvíčalová, Zuzana A1 - Levet, Florian A1 - Benda, Aleš A1 - Letschert, Sebastian A1 - Sauer, Markus A1 - Brdička, Tomáš A1 - Lasser, Theo A1 - Cebecauer, Marek T1 - Quantifying protein densities on cell membranes using super-resolution optical fluctuation imaging JF - Nature Communications N2 - Quantitative approaches for characterizing molecular organization of cell membrane molecules under physiological and pathological conditions profit from recently developed super-resolution imaging techniques. Current tools employ statistical algorithms to determine clusters of molecules based on single-molecule localization microscopy (SMLM) data. These approaches are limited by the ability of SMLM techniques to identify and localize molecules in densely populated areas and experimental conditions of sample preparation and image acquisition. We have developed a robust, model-free, quantitative clustering analysis to determine the distribution of membrane molecules that excels in densely labeled areas and is tolerant to various experimental conditions, i.e. multiple-blinking or high blinking rates. The method is based on a TIRF microscope followed by a super-resolution optical fluctuation imaging (SOFI) analysis. The effectiveness and robustness of the method is validated using simulated and experimental data investigating nanoscale distribution of CD4 glycoprotein mutants in the plasma membrane of T cells. KW - biology KW - fluorescence imaging KW - imaging the immune system KW - super-resolution microscopy Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172993 VL - 8 ER - TY - JOUR A1 - Kasaragod, Prasad A1 - Midekessa, Getnet B. A1 - Sridhar, Shruthi A1 - Schmitz, Werner A1 - Kiema, Tiila-Riikka A1 - Hiltunen, Jukka K. A1 - Wierenga, Rik K. T1 - Structural enzymology comparisons of multifunctional enzyme, type-1 (MFE1): the flexibility of its dehydrogenase part JF - FEBS Open Bio N2 - Multifunctional enzyme, type-1 (MFE1) is a monomeric enzyme with a 2E-enoyl-CoA hydratase and a 3S-hydroxyacyl-CoA dehydrogenase (HAD) active site. Enzyme kinetic data of rat peroxisomal MFE1 show that the catalytic efficiencies for converting the short-chain substrate 2E-butenoyl-CoA into acetoacetyl-CoA are much lower when compared with those of the homologous monofunctional enzymes. The mode of binding of acetoacetyl-CoA (to the hydratase active site) and the very similar mode of binding of NAD\(^+\) and NADH (to the HAD part) are described and compared with those of their monofunctional counterparts. Structural comparisons suggest that the conformational flexibility of the HAD and hydratase parts of MFE1 are correlated. The possible importance of the conformational flexibility of MFE1 for its biocatalytic properties is discussed. KW - biology KW - CoA KW - crotonase KW - dehydrogenase KW - NAD KW - substrate channeling Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172732 VL - 7 IS - 12 ER - TY - JOUR A1 - Temme, Sebastian A1 - Friebe, Daniela A1 - Schmidt, Timo A1 - Poschmann, Gereon A1 - Hesse, Julia A1 - Steckel, Bodo A1 - Stühler, Kai A1 - Kunz, Meik A1 - Dandekar, Thomas A1 - Ding, Zhaoping A1 - Akhyari, Payam A1 - Lichtenberg, Artur A1 - Schrader, Jürgen T1 - Genetic profiling and surface proteome analysis of human atrial stromal cells and rat ventricular epicardium-derived cells reveals novel insights into their cardiogenic potential JF - Stem Cell Research N2 - Epicardium-derived cells (EPDC) and atrial stromal cells (ASC) display cardio-regenerative potential, but the molecular details are still unexplored. Signals which induce activation, migration and differentiation of these cells are largely unknown. Here we have isolated rat ventricular EPDC and rat/human ASC and performed genetic and proteomic profiling. EPDC and ASC expressed epicardial/mesenchymal markers (WT-1, Tbx18, CD73,CD90, CD44, CD105), cardiac markers (Gata4, Tbx5, troponin T) and also contained phosphocreatine. We used cell surface biotinylation to isolate plasma membrane proteins of rEPDC and hASC, Nano-liquid chromatography with subsequent mass spectrometry and bioinformatics analysis identified 396 rat and 239 human plasma membrane proteins with 149 overlapping proteins. Functional GO-term analysis revealed several significantly enriched categories related to extracellular matrix (ECM), cell migration/differentiation, immunology or angiogenesis. We identified receptors for ephrin and growth factors (IGF, PDGF, EGF, anthrax toxin) known to be involved in cardiac repair and regeneration. Functional category enrichment identified clusters around integrins, PI3K/Akt-signaling and various cardiomyopathies. Our study indicates that EPDC and ASC have a similar molecular phenotype related to cardiac healing/regeneration. The cell surface proteome repository will help to further unravel the molecular details of their cardio-regenerative potential and their role in cardiac diseases. KW - Biology KW - Epicardium-derived cells KW - Human atrial stromal cells KW - Cell surface proteomics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172716 VL - 25 ER - TY - JOUR A1 - Costea, Paul I. A1 - Coelho, Louis Pedro A1 - Sunagawa, Shinichi A1 - Munch, Robin A1 - Huerta-Cepas, Jaime A1 - Forslund, Kristoffer A1 - Hildebrand, Falk A1 - Kushugulova, Almagul A1 - Zeller, Georg A1 - Bork, Peer T1 - Subspecies in the global human gut microbiome JF - Molecular Systems Biology N2 - Population genomics of prokaryotes has been studied in depth in only a small number of primarily pathogenic bacteria, as genome sequences of isolates of diverse origin are lacking for most species. Here, we conducted a large‐scale survey of population structure in prevalent human gut microbial species, sampled from their natural environment, with a culture‐independent metagenomic approach. We examined the variation landscape of 71 species in 2,144 human fecal metagenomes and found that in 44 of these, accounting for 72% of the total assigned microbial abundance, single‐nucleotide variation clearly indicates the existence of sub‐populations (here termed subspecies). A single subspecies (per species) usually dominates within each host, as expected from ecological theory. At the global scale, geographic distributions of subspecies differ between phyla, with Firmicutes subspecies being significantly more geographically restricted. To investigate the functional significance of the delineated subspecies, we identified genes that consistently distinguish them in a manner that is independent of reference genomes. We further associated these subspecies‐specific genes with properties of the microbial community and the host. For example, two of the three Eubacterium rectale subspecies consistently harbor an accessory pro‐inflammatory flagellum operon that is associated with lower gut community diversity, higher host BMI, and higher blood fasting insulin levels. Using an additional 676 human oral samples, we further demonstrate the existence of niche specialized subspecies in the different parts of the oral cavity. Taken together, we provide evidence for subspecies in the majority of abundant gut prokaryotes, leading to a better functional and ecological understanding of the human gut microbiome in conjunction with its host. KW - biology KW - genetic variation KW - metagenomics KW - microbiome KW - population structure KW - prokaryotic subspecies Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172674 VL - 13 IS - 12 ER - TY - JOUR A1 - Lapuente, Juan A1 - Arandjelovic, Mimi A1 - Kühl, Hjalmar A1 - Dieguez, Paula A1 - Boesch, Christophe A1 - Linsenmair, K. Eduard T1 - Sustainable Peeling of Kapok Tree (Ceiba pentandra) Bark by the Chimpanzees (Pan troglodytes verus) of Comoé National Park, Ivory Coast JF - International Journal of Primatology N2 - Primates often consume either bark or cambium (inner bark) as a fallback food tocomplete their diet during periods of food scarcity. Wild chimpanzees exhibit greatbehavioral diversity across Africa, as studies of new populations frequently reveal.Since 2014, we have been using a combination of camera traps and indirect signs tostudy the ecology and behavior of wild chimpanzees (Pan troglodytes verus) in ComoéNational Park, Ivory Coast, to document and understand the behavioral adaptations thathelp them to survive in a savanna–forest mosaic landscape. We found that Comoéchimpanzees peel the bark of the buttresses of kapok tree (Ceiba pentandra) trees to eatthe cambium underneath. Individuals of all sex/age classes across at least six neigh-boring communities peeled the bark, but only during the late rainy season andbeginning of the dry season, when cambium may represent an important fallback food.Baboons (Papio anubis) also target the same trees but mainly eat the bark itself. Mostof the bark-peeling wounds onCeibatrees healed completely within 2 years, seeminglywithout any permanent damage. We recorded chimpanzees visiting trees in early stagesof wound recovery but leaving them unpeeled. Only 6% of peeled trees (N= 53) werereexploited after a year, suggesting that chimpanzees waited for the rest of the trees toregrow the bark fully before peeling them again, thus using them sustainably. Manyhuman groups of hunter-gatherers and herders exploited cambium sustainably in thepast. The observation that similar sustainable bark-peeling behavior evolved in bothchimpanzees and humans suggests that it has an important adaptive value in harshenvironments when other food sources become seasonally scarce, by avoiding thedepletion of the resource and keeping it available for periods of scarcity. KW - bark-peeling KW - ceiba pentandra KW - chimpanzee KW - Savanna–Forest mosaic KW - sustainable Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232581 SN - 0164-0291 VL - 41 ER - TY - JOUR A1 - Peters, Marcell K. A1 - Classen, Alice A1 - Müller, Jörg A1 - Steffan‑Dewenter, Ingolf T1 - Increasing the phylogenetic coverage for understanding broad-scale diversity gradients JF - Oecologia N2 - Despite decades of scientific effort, there is still no consensus on the determinants of broad-scale gradients of animal diver-sity. We argue that general drivers of diversity are unlikely to be found among the narrowly defined taxa which are typically analyzed in studies of broad-scale diversity gradients because ecological niches evolve largely conservatively. This causes constraints in the use of available niche space leading to systematic differences in diversity gradients among taxa. We instead advocate studies of phylogenetically diverse animal communities along broad environmental gradients. Such multi-taxa communities are less constrained in resource use and diversification and may be better targets for testing major classical hypotheses on diversity gradients. Besides increasing the spatial scale in analyses, expanding the phylogenetic coverage may be a second way to achieve higher levels of generality in studies of broad-scale diversity gradients KW - elevational diversity KW - DNA metabarcoding KW - negative density dependence KW - productivity hypothesis KW - species energy theory KW - temperature-speciation hypothesis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232519 SN - 0029-8549 VL - 192 ER - TY - JOUR A1 - Kablau, Arne A1 - Berg, Stefan A1 - Rutschmann, Benjamin A1 - Scheiner, Ricarda T1 - Short-term hyperthermia at larval age reduces sucrose responsiveness of adult honeybees and can increase life span JF - Apidologie N2 - Honeybees are very sensitive to their breeding temperature. Even slightly lower temperatures during larval development can significantly affect adult behavior. Several devices which are employed for killing the honeybee ectoparasite Varroa destructor rely on short-term hyperthermia in the honeybee hive. The device used here applies 43.7 °C for 2 h, which is highly effective in killing the mites. We study how short-term hyperthermia affects worker brood and behavior of emerging adult bees. Sucrose responsiveness was strongly reduced after treatment of larvae early or late of larval development. Hyperthermia significantly enhanced life span, particularly in bees receiving treated early in larval development. To ask whether increased life span correlated with foraging performance, we used radio frequency identification (RFID). Onset and offset of foraging behavior as well as foraging trip duration and lifetime foraging effort were unaffected by hyperthermia treatment as prepupa. KW - temperature KW - Varroa destructor KW - worker behavior KW - Apis mellifera KW - RFID KW - température KW - Varroa destructor KW - comportement des travailleurs KW - Apis mellifera KW - RFID KW - Temperatur KW - Varroa destructor KW - Bienenverhalten KW - Apis mellifera KW - RFID Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232462 SN - 0044-8435 VL - 51 ER - TY - JOUR A1 - Schäbler, Stefan A1 - Amatobi, Kelechi M. A1 - Horn, Melanie A1 - Rieger, Dirk A1 - Helfrich‑Förster, Charlotte A1 - Mueller, Martin J. A1 - Wegener, Christian A1 - Fekete, Agnes T1 - Loss of function in the Drosophila clock gene period results in altered intermediary lipid metabolism and increased susceptibility to starvation JF - Cellular and Molecular Life Sciences N2 - The fruit fly Drosophila is a prime model in circadian research, but still little is known about its circadian regulation of metabolism. Daily rhythmicity in levels of several metabolites has been found, but knowledge about hydrophobic metabolites is limited. We here compared metabolite levels including lipids between period\(^{01}\) (per\(^{01}\)) clock mutants and Canton-S wildtype (WT\(_{CS}\)) flies in an isogenic and non-isogenic background using LC–MS. In the non-isogenic background, metabo-lites with differing levels comprised essential amino acids, kynurenines, pterinates, glycero(phospho)lipids, and fatty acid esters. Notably, detectable diacylglycerols (DAG) and acylcarnitines (AC), involved in lipid metabolism, showed lower levels in per\(^{01}\) mutants. Most of these differences disappeared in the isogenic background, yet the level differences for AC as well as DAG were consistent for fly bodies. AC levels were dependent on the time of day in WTCS in phase with food consumption under LD conditions, while DAGs showed weak daily oscillations. Two short-chain ACs continued to cycle even in constant darkness. per\(^{01}\) mutants in LD showed no or very weak diel AC oscillations out of phase with feeding activity. The low levels of DAGs and ACs in per\(^{01}\) did not correlate with lower total food consumption, body mass or weight. Clock mutant flies showed higher sensitivity to starvation independent of their background-dependent activity level. Our results suggest that neither feeding, energy storage nor mobilisation is significantly affected in per\(^{01}\) mutants, but point towards impaired mitochondrial activity, supported by upregulation of the mitochondrial stress marker 4EBP in the clock mutants KW - circadian rhythms KW - metabolomics KW - mitochondrial activity KW - tryptophan KW - acylcarnitine KW - feeding Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232432 SN - 1420-682X VL - 77 ER - TY - JOUR A1 - Schlegel, Jan A1 - Sauer, Markus T1 - Hochaufgelöste Visualisierung einzelner Moleküle auf ganzen Zellen JF - BIOspektrum N2 - Biological systems are dynamic and three-dimensional but many techniques allow only static and two-dimensional observation of cells. We used three-dimensional (3D) lattice light-sheet single-molecule localization microscopy (dSTORM) to investigate the complex interactions and distribution of single molecules in the plasma membrane of whole cells. Different receptor densities of the adhesion receptor CD56 at different parts of the cell highlight the importance and need of three-dimensional observation and analysis techniques. KW - Visualisierung KW - Moleküle KW - Zellen Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232365 SN - 0947-0867 VL - 7 ER - TY - JOUR A1 - Lamaze, Angelique A1 - Öztürk-Çolak, Arzu A1 - Fischer, Robin A1 - Peschel, Nicolai A1 - Koh, Kyunghee A1 - Jepson, James E. C. T1 - Regulation of sleep plasticity by a thermo-sensitive circuit in Drosophila JF - Scientific Reports N2 - Sleep is a highly conserved and essential behaviour in many species, including the fruit fly Drosophila melanogaster. In the wild, sensory signalling encoding environmental information must be integrated with sleep drive to ensure that sleep is not initiated during detrimental conditions. However, the molecular and circuit mechanisms by which sleep timing is modulated by the environment are unclear. Here we introduce a novel behavioural paradigm to study this issue. We show that in male fruit flies, onset of the daytime siesta is delayed by ambient temperatures above 29°C. We term this effect Prolonged Morning Wakefulness (PMW). We show that signalling through the TrpA1 thermo-sensor is required for PMW, and that TrpA1 specifically impacts siesta onset, but not night sleep onset, in response to elevated temperatures. We identify two critical TrpA1-expressing circuits and show that both contact DN1p clock neurons, the output of which is also required for PMW. Finally, we identify the circadian blue-light photoreceptor CRYPTOCHROME as a molecular regulator of PMW, and propose a model in which the Drosophila nervous system integrates information encoding temperature, light, and time to dynamically control when sleep is initiated. Our results provide a platform to investigate how environmental inputs co-ordinately regulate sleep plasticity. KW - Circadian rhythms and sleep KW - Genetics KW - Drosophila melanogaster Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181146 VL - 7 ER - TY - JOUR A1 - Ewald, Jan A1 - Bartl, Martin A1 - Dandekar, Thomas A1 - Kaleta, Christoph T1 - Optimality principles reveal a complex interplay of intermediate toxicity and kinetic efficiency in the regulation of prokaryotic metabolism JF - PLOS Computational Biology N2 - A precise and rapid adjustment of fluxes through metabolic pathways is crucial for organisms to prevail in changing environmental conditions. Based on this reasoning, many guiding principles that govern the evolution of metabolic networks and their regulation have been uncovered. To this end, methods from dynamic optimization are ideally suited since they allow to uncover optimality principles behind the regulation of metabolic networks. We used dynamic optimization to investigate the influence of toxic intermediates in connection with the efficiency of enzymes on the regulation of a linear metabolic pathway. Our results predict that transcriptional regulation favors the control of highly efficient enzymes with less toxic upstream intermediates to reduce accumulation of toxic downstream intermediates. We show that the derived optimality principles hold by the analysis of the interplay between intermediate toxicity and pathway regulation in the metabolic pathways of over 5000 sequenced prokaryotes. Moreover, using the lipopolysaccharide biosynthesis in Escherichia coli as an example, we show how knowledge about the relation of regulation, kinetic efficiency and intermediate toxicity can be used to identify drug targets, which control endogenous toxic metabolites and prevent microbial growth. Beyond prokaryotes, we discuss the potential of our findings for the development of antifungal drugs. KW - Enzyme regulation KW - Toxicity KW - Metabolic pathways KW - Enzymes KW - Transcriptional control KW - Enzyme kinetics KW - Enzyme metabolism KW - Predictive toxicology Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-180870 VL - 13 IS - 2 ER - TY - JOUR A1 - Flemming, S. A1 - Hankir, M. A1 - Ernestus, R.-I. A1 - Seyfried, F. A1 - Germer, C.-T. A1 - Meybohm, P. A1 - Wurmb, T. A1 - Vogel, U. A1 - Wiegering, A. T1 - Surgery in times of COVID-19 — recommendations for hospital and patient management JF - Langenbeck's Archives of Surgery N2 - Background The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has escalated rapidly to a global pandemic stretching healthcare systems worldwide to their limits. Surgeonshave had to immediately react to this unprecedented clinical challenge by systematically repurposing surgical wards. Purpose To provide a detailed set of guidelines developed in a surgical ward at University Hospital Wuerzburg to safelyaccommodate the exponentially rising cases of SARS-CoV-2 infected patients without compromising the care of emergencysurgery and oncological patients or jeopardizing the well-being of hospital staff. Conclusions The dynamic prioritization of SARS-CoV-2 infected and surgical patient groups is key to preserving life whilemaintaining high surgical standards. Strictly segregating patient groups in emergency rooms, non-intensive care wards andoperating areas prevents viral spread while adequately training and carefully selecting hospital staff allow them to confidentlyand successfully undertake their respective clinical duties. KW - SARS-CoV-2 KW - COVID-19 KW - Surgery Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231766 SN - 1435-2443 VL - 405 ER - TY - JOUR A1 - Bae, Soyeon A1 - Heidrich, Lea A1 - Levick, Shaun R. A1 - Gossner, Martin M. A1 - Seibold, Sebastian A1 - Weisser, Wolfgang W. A1 - Magdon, Paul A1 - Serebryanyk, Alla A1 - Bässler, Claus A1 - Schäfer, Deborah A1 - Schulze, Ernst-Detlef A1 - Doerfler, Inken A1 - Müller, Jörg A1 - Jung, Kirsten A1 - Heurich, Marco A1 - Fischer, Markus A1 - Roth, Nicolas A1 - Schall, Peter A1 - Boch, Steffen A1 - Wöllauer, Stephan A1 - Renner, Swen C. A1 - Müller, Jörg T1 - Dispersal ability, trophic position and body size mediate species turnover processes: Insights from a multi-taxa and multi-scale approach JF - Diversity and Distribution N2 - Aim: Despite increasing interest in β-diversity, that is the spatial and temporal turnover of species, the mechanisms underlying species turnover at different spatial scales are not fully understood, although they likely differ among different functional groups. We investigated the relative importance of dispersal limitations and the environmental filtering caused by vegetation for local, multi-taxa forest communities differing in their dispersal ability, trophic position and body size. Location: Temperate forests in five regions across Germany. Methods: In the inter-region analysis, the independent and shared effects of the regional spatial structure (regional species pool), landscape spatial structure (dispersal limitation) and environmental factors on species turnover were quantified with a 1-ha grain across 11 functional groups in up to 495 plots by variation partitioning. In the intra-region analysis, the relative importance of three environmental factors related to vegetation (herb and tree layer composition and forest physiognomy) and spatial structure for species turnover was determined. Results: In the inter-region analysis, over half of the explained variation in community composition (23% of the total explained 35%) was explained by the shared effects of several factors, indicative of spatially structured environmental filtering. Among the independent effects, environmental factors were the strongest on average over 11 groups, but the importance of landscape spatial structure increased for less dispersive functional groups. In the intra-region analysis, the independent effect of plant species composition had a stronger influence on species turnover than forest physiognomy, but the relative importance of the latter increased with increasing trophic position and body size. Main conclusions: Our study revealed that the mechanisms structuring assemblage composition are associated with the traits of functional groups. Hence, conservation frameworks targeting biodiversity of multiple groups should cover both environmental and biogeographical gradients. Within regions, forest management can enhance β-diversity particularly by diversifying tree species composition and forest physiognomy. KW - body size KW - dispersal ability KW - environmental filtering KW - forest physiognomy KW - neutral processes KW - plant composition KW - regional species pool KW - species turnover KW - trophic position KW - β-diversity Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236117 VL - 27 IS - 3 ER - TY - JOUR A1 - Petrov, Ivan A1 - Gentschev, Ivaylo A1 - Vyalkova, Anna A1 - Elashry, Mohamed I. A1 - Klymiuk, Michele C. A1 - Arnhold, Stefan A1 - Szalay, Aladar A. T1 - Canine Adipose-Derived Mesenchymal Stem Cells (cAdMSCs) as a "Trojan Horse" in Vaccinia Virus Mediated Oncolytic Therapy against Canine Soft Tissue Sarcomas JF - Viruses N2 - Several oncolytic viruses (OVs) including various human and canine adenoviruses, canine distemper virus, herpes-simplex virus, reovirus, and members of the poxvirus family, such as vaccinia virus and myxoma virus, have been successfully tested for canine cancer therapy in preclinical and clinical settings. The success of the cancer virotherapy is dependent on the ability of oncolytic viruses to overcome the attacks of the host immune system, to preferentially infect and lyse cancer cells, and to initiate tumor-specific immunity. To date, several different strategies have been developed to overcome the antiviral host defense barriers. In our study, we used canine adipose-derived mesenchymal stem cells (cAdMSCs) as a “Trojan horse” for the delivery of oncolytic vaccinia virus Copenhagen strain to achieve maximum oncolysis against canine soft tissue sarcoma (CSTS) tumors. A single systemic administration of vaccinia virus-loaded cAdMSCs was found to be safe and led to the significant reduction and substantial inhibition of tumor growth in a CSTS xenograft mouse model. This is the first example that vaccinia virus-loaded cAdMSCs could serve as a therapeutic agent against CSTS tumors. KW - oncolytic virus KW - cancer KW - vaccinia virus KW - canine cancer cell lines KW - canine adipose-derived mesenchymal stem cells (cAdMSCs) KW - canine soft tissue sarcoma (CSTS) KW - canine cancer therapy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236007 VL - 12 IS - 7 ER - TY - JOUR A1 - Boschert, Verena A1 - Klenk, Nicola A1 - Abt, Alexander A1 - Raman, Sudha Janaki A1 - Fischer, Markus A1 - Brands, Roman C. A1 - Seher, Axel A1 - Linz, Christian A1 - Müller-Richter, Urs D. A. A1 - Bischler, Thorsten A1 - Hartmann, Stefan T1 - The influence of Met receptor level on HGF-induced glycolytic reprogramming in head and neck squamous cell carcinoma JF - International Journal of Molecular Sciences N2 - Head and neck squamous cell carcinoma (HNSCC) is known to overexpress a variety of receptor tyrosine kinases, such as the HGF receptor Met. Like other malignancies, HNSCC involves a mutual interaction between the tumor cells and surrounding tissues and cells. We hypothesized that activation of HGF/Met signaling in HNSCC influences glucose metabolism and therefore substantially changes the tumor microenvironment. To determine the effect of HGF, we submitted three established HNSCC cell lines to mRNA sequencing. Dynamic changes in glucose metabolism were measured in real time by an extracellular flux analyzer. As expected, the cell lines exhibited different levels of Met and responded differently to HGF stimulation. As confirmed by mRNA sequencing, the level of Met expression was associated with the number of upregulated HGF-dependent genes. Overall, Met stimulation by HGF leads to increased glycolysis, presumably mediated by higher expression of three key enzymes of glycolysis. These effects appear to be stronger in Met\(^{high}\)-expressing HNSCC cells. Collectively, our data support the hypothesized role of HGF/Met signaling in metabolic reprogramming of HNSCC. KW - HNSCC KW - head and neck cancer KW - HGF KW - Met KW - cancer metabolism Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235995 SN - 1422-0067 VL - 21 IS - 2 ER - TY - THES A1 - Vollmuth, Nadine T1 - Role of the proto-oncogene c-Myc in the development of Chlamydia trachomatis T1 - Die Rolle des proto-onkogenes c-Myc in der Entwicklung von Chlamydia trachomatis N2 - Chlamydia trachomatis, an obligate intracellular human pathogen, is the world’s leading cause of infection related blindness and the most common, bacterial sexually transmitted disease. In order to establish an optimal replicative niche, the pathogen extensively interferes with the physiology of the host cell. Chlamydia switches in its complex developmental cycle between the infectious non-replicative elementary bodies (EBs) and the non-infectious replicative reticulate bodies (RBs). The transformation to RBs, shortly after entering a host cell, is a crucial process in infection to start chlamydial replication. Currently it is unknown how the transition from EBs to RBs is initiated. In this thesis, we could show that, in an axenic media approach, L glutamine uptake by the pathogen is crucial to initiate the EB to RB transition. L-glutamine is converted to amino acids which are used by the bacteria to synthesize peptidoglycan. Peptidoglycan inturn is believed to function in separating dividing Chlamydia. The glutamine metabolism is reprogrammed in infected cells in a c-Myc-dependent manner, in order to accomplish the increased requirement for L-glutamine. Upon a chlamydial infection, the proto-oncogene c-Myc gets upregulated to promote host cell glutaminolysis via glutaminase GLS1 and the L-glutamine transporter SLC1A5/ASCT2. Interference with this metabolic reprogramming leads to limited growth of C. trachomatis. Besides the active infection, Chlamydia can persist over a long period of time within the host cell whereby chronic and recurrent infections establish. C. trachomatis acquire a persistent state during an immune attack in response to elevated interferon-γ (IFN-γ) levels. It has been shown that IFN-γ activates the catabolic depletion of L-tryptophan via indoleamine 2,3-dioxygenase (IDO), resulting in the formation of non-infectious atypical chlamydial forms. In this thesis, we could show that IFN-γ depletes the key metabolic regulator c-Myc, which has been demonstrated to be a prerequisite for chlamydial development and growth, in a STAT1-dependent manner. Moreover, metabolic analyses revealed that the pathogen de routs the host cell TCA cycle to enrich pyrimidine biosynthesis. Supplementing pyrimidines or a-ketoglutarate helps the bacteria to partially overcome the persistent state. Together, the results indicate a central role of c-Myc induced host glutamine metabolism reprogramming and L-glutamine for the development of C. trachomatis, which may provide a basis for anti-infectious strategies. Furthermore, they challenge the longstanding hypothesis of L-tryptophan shortage as the sole reason for IFN-γ induced persistence and suggest a pivotal role of c-Myc in the control of the C. trachomatis dormancy. N2 - Chlamydia trachomatis, ein obligat intrazellul¨ares humanes Pathogen, ist weltweit fu¨hrende Ursache fu¨r infektionsbedingte Erblindung und die h¨aufigste, bakterielle sexuell u¨bertragbare Krankheit. Um eine optimale Replikationsnische zu etablieren, interagiert das Pathogen in tensiv mit der Physiologie der Wirtszelle. Chlamydien wechseln in ihrem komplexen Entwick lungszyklus zwischen den infekti¨osen nicht replizierenden Elementark¨orperchen (EBs) und den nicht infekti¨osen replizierenden Retikulark¨orperchen (RBs), und diese Umwandlung in RBs kurz nach dem Eintritt in die Wirtszelle ist ein entscheidender Prozess in der Infektion, um die Replikation des Bakteriums einzuleiten. Derzeit ist noch nicht bekannt, wodurch diese Transformation von EBs zu RBs eingeleitet wird. In dieser Arbeit konnte gezeigt werden, dass bei einer zellfreien Kultivierung des Pathogens die Aufnahme von Glutamin durch den Erreger entscheidend ist, um den ¨Ubergang von EB zu RB zu initiieren. Vor kurzem wurde Peptidoglykan in den Septen von sich replizierenden Chlamydien nachgewiesen. Fu¨r die Syn these des Peptidoglykans nutzen die Bakterien das aufgenommene Glutamin. Der Glutamin metabolismus wird in infizierten Zellen c-Myc abh¨angig umprogrammiert, um den erh¨ohten Bedarf an Glutamin zu bew¨altigen. Bei einer Chlamydieninfektion wird das Proto-Onkogen c-Myc zur F¨orderung der Glutaminolyse der Wirtszelle u¨ber die Glutaminase GLS1 und den Glutamin Transporter SLC1A5/ASCT2 hochreguliert. Ein Eingreifen in diese metabolische Neuprogrammierung fu¨hrt zu einem reduzierten Wachstum von C. trachomatis. Neben der aktiven Infektion k¨onnen Chlamydien u¨ber einen sehr langen Zeitraum in der Wirtszelle persistieren, wodurch es zur Etablierung von chronischen und wiederkehrenden Infektionen kommt. C. trachomatis verf¨allt bei einem Immunangriff in Persistenz, wenn sie auf das freigesetzte Interferon-γ treffen. Es ist bekannt, dass Interferon-γ den Katabolismus von Tryptophan mittels indoleamine 2,3-dioxygenase (IDO) aktiviert, was zur Bildung von nicht infekti¨osen atypischen Chlamydienformen fu¨hrt. In dieser Arbeit konnte gezeigt werden, dass Interferon-γ den zentralen Stoffwechselregulator c-Myc, der sich fu¨r die Entwicklung und das Wachstum von Chlamydien als essentiell erwiesen hat, in Abh¨angigkeit von STAT1 herunter reguliert. Daru¨ber hinaus zeigte die Analyse des Metabolismus, dass das Pathogen den TCA Zyklus der Wirtszelle umleitet, um die Pyrimidinbiosynthese zu unterstu¨tzen. Die Zugabe von Pyrimidinen oder α-Ketoglutarat hilft den Bakterien den Status der Persistenz teilweise zu u¨berwinden. Zusammengenommen deuten die Ergebnisse auf eine zentrale Rolle der c-Myc induzierten Umprogrammierung des Glutaminmetabolismus und des Glutamins selbst fu¨r die Entwicklung von C. trachomatis hin. Diese Befunde k¨onnten eine Basis fu¨r Strategien gegen eine Infektion darstellen. Weiterhin stellen sie die seit langem bestehende Hypothese des Trypotphanmangels als alleiniger Grund fu¨r die von Interferon-γ induzierte Persistenz in Frage und legen eine zentrale Rolle von c-Myc bei der Kontrolle der C. trachomatis Dormanz nahe. KW - Chlamydia trachomatis KW - Persistence KW - trachomatis KW - chlamydia Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203655 ER - TY - JOUR A1 - Classen, Alice A1 - Eardley, Connal D. A1 - Hemp, Andreas A1 - Peters, Marcell K. A1 - Peters, Ralph S. A1 - Ssymank, Axel A1 - Steffan-Dewenter, Ingolf T1 - Specialization of plant-pollinator interactions increases with temperature at Mt. Kilimanjaro JF - Ecology and Evolution N2 - Aim: Species differ in their degree of specialization when interacting with other species, with significant consequences for the function and robustness of ecosystems. In order to better estimate such consequences, we need to improve our understanding of the spatial patterns and drivers of specialization in interaction networks. Methods: Here, we used the extensive environmental gradient of Mt. Kilimanjaro (Tanzania, East Africa) to study patterns and drivers of specialization, and robustness of plant–pollinator interactions against simulated species extinction with standardized sampling methods. We studied specialization, network robustness and other network indices of 67 quantitative plant–pollinator networks consisting of 268 observational hours and 4,380 plant–pollinator interactions along a 3.4 km elevational gradient. Using path analysis, we tested whether resource availability, pollinator richness, visitation rates, temperature, and/or area explain average specialization in pollinator communities. We further linked pollinator specialization to different pollinator taxa, and species traits, that is, proboscis length, body size, and species elevational ranges. Results: We found that specialization decreased with increasing elevation at different levels of biological organization. Among all variables, mean annual temperature was the best predictor of average specialization in pollinator communities. Specialization differed between pollinator taxa, but was not related to pollinator traits. Network robustness against simulated species extinctions of both plants and pollinators was lowest in the most specialized interaction networks, that is, in the lowlands. Conclusions: Our study uncovers patterns in plant–pollinator specialization along elevational gradients. Mean annual temperature was closely linked to pollinator specialization. Energetic constraints, caused by short activity timeframes in cold highlands, may force ectothermic species to broaden their dietary spectrum. Alternatively or in addition, accelerated evolutionary rates might facilitate the establishment of specialization under warm climates. Despite the mechanisms behind the patterns have yet to be fully resolved, our data suggest that temperature shifts in the course of climate change may destabilize pollination networks by affecting network architecture. KW - altitudinal gradient KW - climate change KW - ecological network KW - functional traits KW - generalization KW - mutualistic interactions KW - network specialization index (H2′) KW - pollination KW - robustness KW - specialization Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235959 VL - 10 IS - 4 ER - TY - THES A1 - Roth, Nicolas Mériadec Max André T1 - Temporal development of communities with a focus on insects, in time series of one to four decades T1 - Entwicklung von Artengemeinschaften in der Zeit mit einem Fokus auf Insekten in Zeitreihen von einer bis vier Dekaden N2 - Changes and development are fundamental principles in biocenoses and can affect a multitude of ecological processes. In insect communities phenological and density changes, changes in species richness and community composition, as well as interactions between those changes, are the most important macro processes. However, climate change and other factors like habitat degradation and loss alter these processes leading to shifts and general biodiversity declines. Even though knowledge about insect decline in central Europe increased during the last decades, there are significant knowledge gaps about the development of insect communities in certain habitats and taxa. For example, insect communities in small lentic as well as in forested habitats are under-sampled and reported to be less endangered than communities in other habitats. Furthermore, the changes within habitats and taxa are additionally influenced by certain traits, like host or feeding specialization. To disentangle these influences and to increase the knowledge about the general long-term development of insect communities, comprehensive long-term monitoring studies are needed. In addition, long-term effects of conservation strategies should also be evaluated on large time scales in order to be able to decide on a scientific base which strategies are effective in promoting possibly declining taxa. Hence, this thesis also tackles the effects of an integrative conservation strategy on wood dependent beetle and fungi, beside the development of water beetle and macro moth communities over multiple decades. In Chapter 2 I present a study on the development of water beetle communities (Dytiscidae, Haliplidae, Noteridae) in 33 water bodies in Southern Germany from 1991 to 2018. Time-standardized capture per waterbody was used during three periods: between 1991 and 1995, 2007 and 2008, and 2017 and 2018. Results showed annual declines in both species number (ca. -1%) and abundance (ca. -2%). In addition, community composition shifted over time in part due to changing pH values. Hence, the recorded changes during the 28-year study period partly reflect natural succession processes. However, since also moor-related beetle species decreased significantly, it is likely that water beetles in southern Germany are also threatened by non-successional factors, including desiccation, increased nitrogen input and/or mineralization, as well as the loss of specific habitats. The results suggest, that in small to midsize lentic waterbodies, current development should aim for constant creation of new water bodies and protection of moor waterbodies in order to protect water beetle communities on a landscape scale. In Chapter 3 I present an analysis of the development of nocturnal macro moth species richness, abundance and biomass over four decades in forests of southern Germany. Two local scale data sets featuring a coppiced oak forest as well as an oak high forest were analysed separately from a regional data set representing all forest types in the temperate zone of Central Europe. At the regional scale species richness, abundance and biomass showed annual declines of ca. 1 %, 1.3 % and 1.4 %, respectively. These declines were more pronounced in plant host specialists and in dark coloured species. In contrast, species richness increased by ca. 1.5 % annually in the coppiced forest, while no significant trends were found in the high forest. In contrast to past assumptions, insect decline apparently affects also hyper diverse insect groups in forests. Since host specialists and dark coloured species were affected more heavily by the decline than other groups, habitat loss and climate change seem to be potential drivers of the observed trends. However, the positive development of species richness in the coppiced oak forest indicates that maintaining complex and diverse forest ecosystems through active management might compensate for negative trends in biodiversity. Chapter 4 features a study specifically aiming to investigate the long-term effect of deadwood enrichment as an integrative conservation strategy on saproxylic beetles and fungi in a central European beech forest at a landscape scale. A before–after control–impact design, was used to compare assemblages and gamma diversities of saproxylic organisms (beetles and fungi) in strictly protected old-growth forest areas (reserves) and previously moderately and intensively managed forest areas. Forests were sampled one year before and a decade after starting a landscape-wide strategy of dead-wood enrichment. Ten years after the start of the dead-wood enrichment, neither gamma diversities of saproxylic organisms nor species composition of beetles did reflect the previous management types anymore. However, fungal species composition still mirrored the previous management gradient. The results demonstrated that intentional enrichment of dead wood at the landscape scale can effectively restore communities of saproxylic organisms and may thus be a suitable strategy in addition to permanent strict reserves in order to protect wood dependent organisms in Europe. In this thesis I showed, that in contrast to what was assumed and partly reported so far, also water beetles in lentic water bodies and macro moths in forests decreased in species richness, abundance and biomass during the last three to four decades. In line with earlier studies, especially dark coloured species and specialists decreased more than light-coloured species and generalists. The reasons for these declines could partly be attributed to natural processes and pollution and possibly to climate change. However, further studies, especially experimental ones, will be needed to achieve a better understanding of the reasons for insect decline. Furthermore, analyses of time series data should be interpreted cautiously especially if the number of sampling years is smaller than ten years. In addition, validation techniques such as left- and right- censoring and cross validation should be used in order to proof the robustness of the analyses. However, the lack of knowledge, we are still facing today, should not prevent scientists and practitioners from applying conservation measures. In order to prove the effectiveness of such measures, long-term monitoring is crucial. Such control of success is essential for evidence based and thus adapted conservation strategies of threatened organisms. N2 - Veränderungen und Entwicklung sind grundlegende Prinzipien in Biozönosen und können eine Vielzahl von ökologischen Prozessen beeinflussen. In Insektengemeinschaften stellen Veränderungen in der Phänologie und Dichte, Veränderungen des Artenreichtums und der Artenzusammensetzung sowie die Wechselwirkungen zwischen diesen, die wichtigsten Makroprozesse dar. Klimawandel und andere Faktoren wie der Verlust von Lebensräumen oder deren Qualitätsverschlechterung beeinflussen diese Prozesse jedoch und führen zu Veränderungen und allgemeinen Rückgängen der Biodiversität. Auch wenn die Erkenntnisse zum „Insektensterben“ in Mitteleuropa in den letzten Jahrzehnten zugenommen haben, gibt es erhebliche Wissenslücken über die Entwicklung von Insektengemeinschaften in bestimmten Lebensräumen und Taxa. Beispielsweise ist die Entwicklung von Insektengemeinschaften in kleinen, stehenden Gewässern und in Wäldern wenig erforscht. Darüber hinaus werden die Veränderungen innerhalb von Habitaten und Taxa zusätzlich durch bestimmte Merkmale, wie Wirts- oder Nahrungsspezialisierung, beeinflusst. Um diese verschiedenen Einflüsse auseinanderhalten zu können und das Wissen über die allgemeine Langzeitentwicklung von Insektengemeinschaften zu vergrößern, sind umfassende Langzeitstudien erforderlich. Darüber hinaus sollten auch die langfristigen Auswirkungen von Naturschutzstrategien über lange Zeiträume evaluiert werden, um auf wissenschaftlicher Grundlage entscheiden zu können, welche Strategien zur Förderung bedrohter Taxa wirksam sind. Daher befasst sich diese Arbeit neben der Entwicklung von Wasserkäfer- und Großschmetterlingsgemeinschaften über mehrere Jahrzehnte auch mit den Auswirkungen einer integrativen Naturschutzmaßnahme auf xylobionte Käfer und Pilze. In Kapitel 2 stelle ich eine Studie über die Entwicklung von Wasserkäfergemeinschaften (Dytiscidae, Haliplidae, Noteridae) in 33 Gewässern Süddeutschlands von 1991 bis 2018 vor. Die zeitstandardisierte Erfassung pro Wasserkörper erfolgte in drei Zeiträumen: zwischen 1991 und 1995, 2007 und 2008 sowie 2017 und 2018. Die Ergebnisse zeigten einen jährlichen Rückgang sowohl der Artenzahl (ca. -1%) als auch der Abundanz (ca. -2%). Darüber hinaus verschob sich die Artenzusammensetzung im Laufe der Zeit zum Teil aufgrund sich ändernder pH-Werte. Daraus lässt sich schlussfolgern, dass die erfassten Veränderungen während des 28- jährigen Untersuchungszeitraums teilweise natürliche Sukzessionsprozesse widerspiegeln. Da aber auch an moorige Gewässer gebundene Käferarten deutlich abgenommen haben, ist es wahrscheinlich, dass die Wasserkäfer Süddeutschlands auch durch Faktoren wie Austrocknung, erhöhten Stickstoffeintrag und/oder Mineralisierung sowie durch den Verlust spezifischer Lebensräume bedroht sind. Aufgrund dieser Entwicklungen ist es empfehlenswert, auf Landschaftsebene auf die ständige Schaffung neuer Gewässer und den besonderen Schutz von Moorgewässern zu setzen, um Wasserkäfergemeinschaften erfolgreich schützen zu können. In Kapitel 3 präsentiere ich eine Analyse der Diversitäts-, Abundanz- und Biomassenentwicklung von nachtaktiven Großschmetterlingen über vier Jahrzehnte in Wäldern Süddeutschlands. Neben einem bayernweiten Datensatz, der alle typischen Waldtypen der gemäßigten Zone Mitteleuropas beinhaltet, wurden zwei lokale, besonders regelmäßig besammelte Gebiete getrennt analysiert. In diesen Gebieten werden die Eichenwälder als Hoch- bzw. als Mittelwald bewirtschaftet. Bayernweit wiesen Artenreichtum, Abundanz und Biomasse jährliche Rückgänge von ca. 1 %, 1,3 % bzw. 1,4 % auf. Diese Rückgänge waren bei Wirtspflanzenspezialisten und bei dunkel gefärbten Arten besonders stark ausgeprägt. Im Gegensatz dazu nahm der Artenreichtum im Mittelwald jährlich um ca. 1,5 % zu, während im Hochwald keine signifikanten Trends festgestellt werden konnten. Im Gegensatz zu früheren Annahmen betrifft der Insektenrückgang offenbar auch hyperdiverse Insektengruppen im Wald. Da Wirtspflanzenspezialisten und dunkel gefärbte Arten vom Rückgang stärker betroffen waren als andere, scheinen Lebensraumverlust und Klimawandel potentielle Treiber der beobachteten Trends zu sein. Die positive Entwicklung des Artenreichtums im Mittelwald zeigt jedoch, dass der Erhalt komplexer und vielfältiger Waldökosysteme durch aktives Management, negative Biodiversitätstrends zum Teil kompensieren könnte. Kapitel 4 enthält eine Studie, die die Langzeitwirkung von Totholzanreicherung als integrative Naturschutzmaßnahme auf xylobionte Käfer und Pilze in einem mitteleuropäischen Buchenwald auf der Landschaftsebene untersucht. Dabei wurde die Gamma-Diversität und die Artenzusammensetzung dieser beiden Gruppen anhand einer Vorher-Nachher Untersuchung mit Kontrollflächen (Naturwaldreservate) untersucht. Die bewirtschafteten Flächen wurden weiterhin in zuvor mäßig und intensiv bewirtschaftete Flächen eingeteilt. Die Wälder wurden ein Jahr vor und ein Jahrzehnt nach Beginn einer Totholzanreicherungsstrategie auf Landschaftsebene beprobt. Zehn Jahre nach Beginn der Totholzanreicherung spiegelten weder die Gamma-Diversität der xylobionten Organismen noch die Artenzusammensetzung der Käfer die früheren Bewirtschaftungstypen wider, und wiesen keine Unterschiede mehr zu den Naturwaldreservaten auf. Die Pilzartenzusammensetzung spiegelte jedoch noch immer den früheren Bewirtschaftungsgradienten wider. Die Ergebnisse zeigen, dass Totholzanreicherung auf Landschaftsebene positive Effekte auf xylobionte Artengemeinschaften haben kann. Somit stellt Totholzanreicherung eine Naturschutzmaßnahme dar, die zusätzlich zu permanenten Schutzgebieten, eine Grundlage schaffen kann, um holzabhängige Organismen in Europa zu schützen. In dieser Arbeit habe ich gezeigt, dass im Gegensatz zu dem, was bisher angenommen und zum Teil berichtet wurde, auch Wasserkäfer in stehenden Gewässern und nachtaktive Großschmetterlingen in Wäldern in den letzten drei bis vier Jahrzehnten an Artenreichtum, Abundanz und Biomasse abgenommen haben. In Übereinstimmung mit anderen Studien nahmen vor allem dunkel gefärbte Arten und Spezialisten stärker ab als hell gefärbte Arten und Generalisten. Die Gründe für diese Rückgänge konnten zum Teil auf natürliche Prozesse, Umweltverschmutzung und möglicherweise auf den Klimawandel zurückgeführt werden. Es sind jedoch weitere Studien, insbesondere experimentelle, erforderlich, um die Gründe für das „Insektensterben“ besser zu verstehen. Darüber hinaus sollten Zeitreihendaten mit Vorsicht interpretiert werden, insbesondere wenn die Anzahl der besammelten Jahre kleiner als zehn Jahre ist. Darüber hinaus sollten Validierungstechniken wie Links- und Rechts-Zensierung und Kreuzvalidierung eingesetzt werden, um die Robustheit der Analysen nachzuweisen. Der Mangel an Wissen, mit dem wir heute noch konfrontiert sind, sollte Wissenschaftler und Praktiker jedoch nicht davon abhalten, Naturschutzmaßnahmen anzuwenden. Um die Wirksamkeit solcher Maßnahmen nachzuweisen, ist eine langfristige Überprüfung von entscheidender Bedeutung. Solche Erfolgskontrollen sind für evidenzbasierte und damit angepasste Erhaltungsstrategien bedrohter Organismen unerlässlich. KW - climate change KW - insects KW - temporal development KW - nature conservation KW - entomology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235499 ER - TY - JOUR A1 - De Lira, Maria Nathalia A1 - Raman, Sudha Janaki A1 - Schulze, Almut A1 - Schneider-Schaulies, Sibylle A1 - Avota, Elita T1 - Neutral Sphingomyelinase-2 (NSM 2) Controls T Cell Metabolic Homeostasis and Reprogramming During Activation JF - Frontiers in Molecular Biosciences N2 - Neutral sphingomyelinase-2 (NSM2) is a member of a superfamily of enzymes responsible for conversion of sphingomyelin into phosphocholine and ceramide at the cytosolic leaflet of the plasma membrane. Upon specific ablation of NSM2, T cells proved to be hyper-responsive to CD3/CD28 co-stimulation, indicating that the enzyme acts to dampen early overshooting activation of these cells. It remained unclear whether hyper-reactivity of NSM2-deficient T cells is supported by a deregulated metabolic activity in these cells. Here, we demonstrate that ablation of NSM2 activity affects metabolism of the quiescent CD4\(^+\) T cells which accumulate ATP in mitochondria and increase basal glycolytic activity. This supports enhanced production of total ATP and metabolic switch early after TCR/CD28 stimulation. Most interestingly, increased metabolic activity in resting NSM2-deficient T cells does not support sustained response upon stimulation. While elevated under steady-state conditions in NSM2-deficient CD4\(^+\) T cells, the mTORC1 pathway regulating mitochondria size, oxidative phosphorylation, and ATP production is impaired after 24 h of stimulation. Taken together, the absence of NSM2 promotes a hyperactive metabolic state in unstimulated CD4\(^+\) T cells yet fails to support sustained T cell responses upon antigenic stimulation. KW - neutral sphingomyelinase-2 KW - T cell receptor KW - Seahorse XF KW - oxidative phosphorylation KW - ATP-adenosine triphosphate KW - Mitochondria Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211311 SN - 2296-889X VL - 7 ER - TY - JOUR A1 - Yang, Tao A1 - Heydarian, Motaharehsadat A1 - Kozjak-Pavlovic, Vera A1 - Urban, Manuela A1 - Harbottle, Richard P. A1 - Rudel, Thomas T1 - Folliculin Controls the Intracellular Survival and Trans-Epithelial Passage of Neisseria gonorrhoeae JF - Frontiers in Cellular and Infection Microbiology N2 - Neisseria gonorrhoeae, a Gram-negative obligate human pathogenic bacterium, infects human epithelial cells and causes sexually transmitted diseases. Emerging multi-antibiotic resistant gonococci and increasing numbers of infections complicate the treatment of infected patients. Here, we used an shRNA library screen and next-generation sequencing to identify factors involved in epithelial cell infection. Folliculin (FLCN), a 64 kDa protein with a tumor repressor function was identified as a novel host factor important for N. gonorrhoeae survival after uptake. We further determined that FLCN did not affect N. gonorrhoeae adherence and invasion but was essential for its survival in the cells by modulating autophagy. In addition, FLCN was also required to maintain cell to cell contacts in the epithelial layer. In an infection model with polarized cells, FLCN inhibited the polarized localization of E-cadherin and the transcytosis of gonococci across polarized epithelial cells. In conclusion, we demonstrate here the connection between FLCN and bacterial infection and in particular the role of FLCN in the intracellular survival and transcytosis of gonococci across polarized epithelial cell layers. KW - gonococcal invasion KW - folliculin KW - autophagy KW - polarized epithelium KW - polarized cell culture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211372 SN - 2235-2988 VL - 10 IS - 422 ER - TY - JOUR A1 - Balkenhol, Johannes A1 - Kaltdorf, Kristin V. A1 - Mammadova-Bach, Elmina A1 - Braun, Attila A1 - Nieswandt, Bernhard A1 - Dittrich, Marcus A1 - Dandekar, Thomas T1 - Comparison of the central human and mouse platelet signaling cascade by systems biological analysis JF - BMC Genomics N2 - Background Understanding the molecular mechanisms of platelet activation and aggregation is of high interest for basic and clinical hemostasis and thrombosis research. The central platelet protein interaction network is involved in major responses to exogenous factors. This is defined by systemsbiological pathway analysis as the central regulating signaling cascade of platelets (CC). Results The CC is systematically compared here between mouse and human and major differences were found. Genetic differences were analysed comparing orthologous human and mouse genes. We next analyzed different expression levels of mRNAs. Considering 4 mouse and 7 human high-quality proteome data sets, we identified then those major mRNA expression differences (81%) which were supported by proteome data. CC is conserved regarding genetic completeness, but we observed major differences in mRNA and protein levels between both species. Looking at central interactors, human PLCB2, MMP9, BDNF, ITPR3 and SLC25A6 (always Entrez notation) show absence in all murine datasets. CC interactors GNG12, PRKCE and ADCY9 occur only in mice. Looking at the common proteins, TLN1, CALM3, PRKCB, APP, SOD2 and TIMP1 are higher abundant in human, whereas RASGRP2, ITGB2, MYL9, EIF4EBP1, ADAM17, ARRB2, CD9 and ZYX are higher abundant in mouse. Pivotal kinase SRC shows different regulation on mRNA and protein level as well as ADP receptor P2RY12. Conclusions Our results highlight species-specific differences in platelet signaling and points of specific fine-tuning in human platelets as well as murine-specific signaling differences. KW - interspecies comparison KW - transcriptome KW - proteome KW - platelet KW - network KW - signaling KW - mouse KW - human KW - interactome KW - cascade Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230377 VL - 21 ER - TY - JOUR A1 - Urban, Lara A1 - Remmele, Christian W. A1 - Dittrich, Marcus A1 - Schwarz, Roland F. A1 - Müller, Tobias T1 - covRNA: discovering covariate associations in large-scale gene expression data JF - BMC Reserach Notes N2 - Objective The biological interpretation of gene expression measurements is a challenging task. While ordination methods are routinely used to identify clusters of samples or co-expressed genes, these methods do not take sample or gene annotations into account. We aim to provide a tool that allows users of all backgrounds to assess and visualize the intrinsic correlation structure of complex annotated gene expression data and discover the covariates that jointly affect expression patterns. Results The Bioconductor package covRNA provides a convenient and fast interface for testing and visualizing complex relationships between sample and gene covariates mediated by gene expression data in an entirely unsupervised setting. The relationships between sample and gene covariates are tested by statistical permutation tests and visualized by ordination. The methods are inspired by the fourthcorner and RLQ analyses used in ecological research for the analysis of species abundance data, that we modified to make them suitable for the distributional characteristics of both, RNA-Seq read counts and microarray intensities, and to provide a high-performance parallelized implementation for the analysis of large-scale gene expression data on multi-core computational systems. CovRNA provides additional modules for unsupervised gene filtering and plotting functions to ensure a smooth and coherent analysis workflow. KW - Multivariate analysis KW - Fourthcorner analysis KW - RLQ analysis KW - Transcriptomics KW - High-throughput data KW - Visualization KW - Ordination methods KW - RNA-Seq analysis KW - Microarray analysis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229258 VL - 13 ER - TY - JOUR A1 - Vogel, Cassandra A1 - Chunga, Timothy L. A1 - Sun, Xiaoxuan A1 - Poveda, Katja A1 - Steffan-Dewenter, Ingolf T1 - Higher bee abundance, but not pest abundance, in landscapes with more agriculture on a late-flowering legume crop in tropical smallholder farms JF - PeerJ N2 - Background Landscape composition is known to affect both beneficial insect and pest communities on crop fields. Landscape composition therefore can impact ecosystem (dis)services provided by insects to crops. Though landscape effects on ecosystem service providers have been studied in large-scale agriculture in temperate regions, there is a lack of representation of tropical smallholder agriculture within this field of study, especially in sub-Sahara Africa. Legume crops can provide important food security and soil improvement benefits to vulnerable agriculturalists. However, legumes are dependent on pollinating insects, particularly bees (Hymenoptera: Apiformes) for production and are vulnerable to pests. We selected 10 pigeon pea (Fabaceae: Cajunus cajan (L.)) fields in Malawi with varying proportions of semi-natural habitat and agricultural area within a 1 km radius to study: (1) how the proportion of semi-natural habitat and agricultural area affects the abundance and richness of bees and abundance of florivorous blister beetles (Coleoptera: Melloidae), (2) if the proportion of flowers damaged and fruit set difference between open and bagged flowers are correlated with the proportion of semi-natural habitat or agricultural area and (3) if pigeon pea fruit set difference between open and bagged flowers in these landscapes was constrained by pest damage or improved by bee visitation. Methods We performed three, ten-minute, 15 m, transects per field to assess blister beetle abundance and bee abundance and richness. Bees were captured and identified to (morpho)species. We assessed the proportion of flowers damaged by beetles during the flowering period. We performed a pollinator and pest exclusion experiment on 15 plants per field to assess whether fruit set was pollinator limited or constrained by pests. Results In our study, bee abundance was higher in areas with proportionally more agricultural area surrounding the fields. This effect was mostly driven by an increase in honeybees. Bee richness and beetle abundances were not affected by landscape characteristics, nor was flower damage or fruit set difference between bagged and open flowers. We did not observe a positive effect of bee density or richness, nor a negative effect of florivory, on fruit set difference. Discussion In our study area, pigeon pea flowers relatively late—well into the dry season. This could explain why we observe higher densities of bees in areas dominated by agriculture rather than in areas with more semi-natural habitat where resources for bees during this time of the year are scarce. Therefore, late flowering legumes may be an important food resource for bees during a period of scarcity in the seasonal tropics. The differences in patterns between our study and those conducted in temperate regions highlight the need for landscape-scale studies in areas outside the temperate region. KW - Pollination KW - Small-holder agriculture KW - Legume crops KW - Insect pests KW - Tropical agriculture KW - Landscape ecology KW - Plant-insect interactions KW - African agriculture KW - Ecosystem services KW - Agro-ecology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231491 VL - 9 ER - TY - JOUR A1 - Helfrich-Förster, C. A1 - Monecke, S. A1 - Spiousas, I. A1 - Hovestadt, T. A1 - Mitesser, O. A1 - Wehr, T. A. T1 - Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon JF - Science Advances N2 - Many species synchronize reproductive behavior with a particular phase of the lunar cycle to increase reproductive success. In humans, a lunar influence on reproductive behavior remains controversial, although the human menstrual cycle has a period close to that of the lunar cycle. Here, we analyzed long-term menstrual recordings of individual women with distinct methods for biological rhythm analysis. We show that women’s menstrual cycles with a period longer than 27 days were intermittently synchronous with the Moon’s luminance and/or gravimetric cycles. With age and upon exposure to artificial nocturnal light, menstrual cycles shortened and lost this synchrony. We hypothesize that in ancient times, human reproductive behavior was synchronous with the Moon but that our modern lifestyles have changed reproductive physiology and behavior. KW - moon KW - menstrual cycles Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231479 VL - 7 IS - 5 ER - TY - JOUR A1 - Kühnemundt, Johanna A1 - Leifeld, Heidi A1 - Scherg, Florian A1 - Schmitt, Matthias A1 - Nelke, Lena C. A1 - Schmitt, Tina A1 - Bauer, Florentin A1 - Göttlich, Claudia A1 - Fuchs, Maximilian A1 - Kunz, Meik A1 - Peindl, Matthias A1 - Brähler, Caroline A1 - Kronenthaler, Corinna A1 - Wischhusen, Jörg A1 - Prelog, Martina A1 - Walles, Heike A1 - Dandekar, Thomas A1 - Dandekar, Gudrun A1 - Nietzer, Sarah L. T1 - Modular micro-physiological human tumor/tissue models based on decellularized tissue for improved preclinical testing JF - ALTEX N2 - High attrition-rates entailed by drug testing in 2D cell culture and animal models stress the need for improved modeling of human tumor tissues. In previous studies our 3D models on a decellularized tissue matrix have shown better predictivity and higher chemoresistance. A single porcine intestine yields material for 150 3D models of breast, lung, colorectal cancer (CRC) or leukemia. The uniquely preserved structure of the basement membrane enables physiological anchorage of endothelial cells and epithelial-derived carcinoma cells. The matrix provides different niches for cell growth: on top as monolayer, in crypts as aggregates and within deeper layers. Dynamic culture in bioreactors enhances cell growth. Comparing gene expression between 2D and 3D cultures, we observed changes related to proliferation, apoptosis and stemness. For drug target predictions, we utilize tumor-specific sequencing data in our in silico model finding an additive effect of metformin and gefitinib treatment for lung cancer in silico, validated in vitro. To analyze mode-of-action, immune therapies such as trispecific T-cell engagers in leukemia, as well as toxicity on non-cancer cells, the model can be modularly enriched with human endothelial cells (hECs), immune cells and fibroblasts. Upon addition of hECs, transmigration of immune cells through the endothelial barrier can be investigated. In an allogenic CRC model we observe a lower basic apoptosis rate after applying PBMCs in 3D compared to 2D, which offers new options to mirror antigen-specific immunotherapies in vitro. In conclusion, we present modular human 3D tumor models with tissue-like features for preclinical testing to reduce animal experiments. KW - modular tumor tissue models KW - invasiveness KW - bioreactor culture KW - combinatorial drug predictions KW - immunotherapies Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231465 VL - 38 ER - TY - JOUR A1 - Stelzner, Kathrin A1 - Winkler, Ann-Cathrin A1 - Liang, Chunguang A1 - Boyny, Aziza A1 - Ade, Carsten P. A1 - Dandekar, Thomas A1 - Fraunholz, Martin J. A1 - Rudel, Thomas T1 - Intracellular Staphylococcus aureus Perturbs the Host Cell Ca\(^{2+}\) Homeostasis To Promote Cell Death JF - mBio N2 - The opportunistic human pathogen Staphylococcus aureus causes serious infectious diseases that range from superficial skin and soft tissue infections to necrotizing pneumonia and sepsis. While classically regarded as an extracellular pathogen, S. aureus is able to invade and survive within human cells. Host cell exit is associated with cell death, tissue destruction, and the spread of infection. The exact molecular mechanism employed by S. aureus to escape the host cell is still unclear. In this study, we performed a genome-wide small hairpin RNA (shRNA) screen and identified the calcium signaling pathway as being involved in intracellular infection. S. aureus induced a massive cytosolic Ca\(^{2+}\) increase in epithelial host cells after invasion and intracellular replication of the pathogen. This was paralleled by a decrease in endoplasmic reticulum Ca\(^{2+}\) concentration. Additionally, calcium ions from the extracellular space contributed to the cytosolic Ca2+ increase. As a consequence, we observed that the cytoplasmic Ca\(^{2+}\) rise led to an increase in mitochondrial Ca\(^{2+}\) concentration, the activation of calpains and caspases, and eventually to cell lysis of S. aureus-infected cells. Our study therefore suggests that intracellular S. aureus disturbs the host cell Ca\(^{2+}\) homeostasis and induces cytoplasmic Ca\(^{2+}\) overload, which results in both apoptotic and necrotic cell death in parallel or succession. IMPORTANCE Despite being regarded as an extracellular bacterium, the pathogen Staphylococcus aureus can invade and survive within human cells. The intracellular niche is considered a hideout from the host immune system and antibiotic treatment and allows bacterial proliferation. Subsequently, the intracellular bacterium induces host cell death, which may facilitate the spread of infection and tissue destruction. So far, host cell factors exploited by intracellular S. aureus to promote cell death are only poorly characterized. We performed a genome-wide screen and found the calcium signaling pathway to play a role in S. aureus invasion and cytotoxicity. The intracellular bacterium induces a cytoplasmic and mitochondrial Ca\(^{2+}\) overload, which results in host cell death. Thus, this study first showed how an intracellular bacterium perturbs the host cell Ca\(^{2+}\) homeostasis." KW - Staphylococcus aureus KW - calcium signaling pathway KW - cell death KW - facultatively intracellular pathogens Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231448 VL - 11 ER - TY - JOUR A1 - Naseem, Muhammad A1 - Othman, Eman M. A1 - Fathy, Moustafa A1 - Iqbal, Jibran A1 - Howari, Fares M. A1 - AlRemeithi, Fatima A. A1 - Kodandaraman, Geema A1 - Stopper, Helga A1 - Bencurova, Elena A1 - Vlachakis, Dimitrios A1 - Dandekar, Thomas T1 - Integrated structural and functional analysis of the protective effects of kinetin against oxidative stress in mammalian cellular systems JF - Scientific Reports N2 - Metabolism and signaling of cytokinins was first established in plants, followed by cytokinin discoveries in all kingdoms of life. However, understanding of their role in mammalian cells is still scarce. Kinetin is a cytokinin that mitigates the effects of oxidative stress in mammalian cells. The effective concentrations of exogenously applied kinetin in invoking various cellular responses are not well standardized. Likewise, the metabolism of kinetin and its cellular targets within the mammalian cells are still not well studied. Applying vitality tests as well as comet assays under normal and hyper-oxidative states, our analysis suggests that kinetin concentrations of 500 nM and above cause cytotoxicity as well as genotoxicity in various cell types. However, concentrations below 100 nM do not cause any toxicity, rather in this range kinetin counteracts oxidative burst and cytotoxicity. We focus here on these effects. To get insights into the cellular targets of kinetin mediating these pro-survival functions and protective effects we applied structural and computational approaches on two previously testified targets for these effects. Our analysis deciphers vital residues in adenine phosphoribosyltransferase (APRT) and adenosine receptor (A2A-R) that facilitate the binding of kinetin to these two important human cellular proteins. We finally discuss how the therapeutic potential of kinetin against oxidative stress helps in various pathophysiological conditions. KW - cytokinins KW - 6-benzylaminopurine Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231317 VL - 10 ER - TY - JOUR A1 - Sajko, Sara A1 - Grishkovskaya, Irina A1 - Kostan, Julius A1 - Graewert, Melissa A1 - Setiawan, Kim A1 - Trübestein, Linda A1 - Niedermüller, Korbinian A1 - Gehin, Charlotte A1 - Sponga, Antonio A1 - Puchinger, Martin A1 - Gavin, Anne-Claude A1 - Leonard, Thomas A. A1 - Svergun, Dimitri I. A1 - Smith, Terry K. A1 - Morriswood, Brooke A1 - Djinovic-Carugo, Kristina T1 - Structures of three MORN repeat proteins and a re-evaluation of the proposed lipid-binding properties of MORN repeats JF - PLoS One N2 - MORN (Membrane Occupation and Recognition Nexus) repeat proteins have a wide taxonomic distribution, being found in both prokaryotes and eukaryotes. Despite this ubiquity, they remain poorly characterised at both a structural and a functional level compared to other common repeats. In functional terms, they are often assumed to be lipid-binding modules that mediate membrane targeting. We addressed this putative activity by focusing on a protein composed solely of MORN repeats-Trypanosoma brucei MORN1. Surprisingly, no evidence for binding to membranes or lipid vesicles by TbMORN1 could be obtained either in vivo or in vitro. Conversely, TbMORN1 did interact with individual phospholipids. High- and low-resolution structures of the MORN1 protein from Trypanosoma brucei and homologous proteins from the parasites Toxoplasma gondii and Plasmodium falciparum were obtained using a combination of macromolecular crystallography, small-angle X-ray scattering, and electron microscopy. This enabled a first structure-based definition of the MORN repeat itself. Furthermore, all three structures dimerised via their C-termini in an antiparallel configuration. The dimers could form extended or V-shaped quaternary structures depending on the presence of specific interface residues. This work provides a new perspective on MORN repeats, showing that they are protein-protein interaction modules capable of mediating both dimerisation and oligomerisation. KW - recognition nexus domain KW - trypanosoma brucei KW - blood stream KW - phosphatidylserine transport KW - biological macromolecules KW - membrane occupation KW - solution scattering KW - molecular cloning KW - flagellar pocket KW - endocytosis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231261 VL - 15 IS - 23 ER - TY - JOUR A1 - Götz, Ralph A1 - Kunz, Tobias C. A1 - Fink, Julian A1 - Solger, Franziska A1 - Schlegel, Jan A1 - Seibel, Jürgen A1 - Kozjak-Pavlovic, Vera A1 - Rudel, Thomas A1 - Sauer, Markus T1 - Nanoscale imaging of bacterial infections by sphingolipid expansion microscopy JF - Nature Communications N2 - Expansion microscopy (ExM) enables super-resolution imaging of proteins and nucleic acids on conventional microscopes. However, imaging of details of the organization of lipid bilayers by light microscopy remains challenging. We introduce an unnatural short-chain azide- and amino-modified sphingolipid ceramide, which upon incorporation into membranes can be labeled by click chemistry and linked into hydrogels, followed by 4x to 10x expansion. Confocal and structured illumination microscopy (SIM) enable imaging of sphingolipids and their interactions with proteins in the plasma membrane and membrane of intracellular organelles with a spatial resolution of 10-20nm. As our functionalized sphingolipids accumulate efficiently in pathogens, we use sphingolipid ExM to investigate bacterial infections of human HeLa229 cells by Neisseria gonorrhoeae, Chlamydia trachomatis and Simkania negevensis with a resolution so far only provided by electron microscopy. In particular, sphingolipid ExM allows us to visualize the inner and outer membrane of intracellular bacteria and determine their distance to 27.6 +/- 7.7nm. Imaging of lipid bilayers using light microscopy is challenging. Here the authors label cells using a short chain click-compatible ceramide to visualize mammalian and bacterial membranes with expansion microscopy. KW - nanoscale imaging KW - bacterial infection KW - sphingolipid expansion microscopy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231248 VL - 11 ER - TY - JOUR A1 - Markert, Sebastian M. A1 - Skoruppa, Michael A1 - Yu, Bin A1 - Mulcahy, Ben A1 - Zhen, Mai A1 - Gao, Shangbang A1 - Sendtner, Michael A1 - Stigloher, Christian T1 - Overexpression of an ALS-associated FUS mutation in C. elegans disrupts NMJ morphology and leads to defective neuromuscular transmission JF - Biology Open N2 - The amyotrophic lateral sclerosis (ALS) neurodegenerative disorder has been associated with multiple genetic lesions, including mutations in the gene for fused in sarcoma (FUS), a nuclear-localized RNA/DNA-binding protein. Neuronal expression of the pathological form of FUS proteins in Caenorhabditis elegans results in mislocalization and aggregation of FUS in the cytoplasm, and leads to impairment of motility. However, the mechanisms by which the mutant FUS disrupts neuronal health and function remain unclear. Here we investigated the impact of ALS-associated FUS on motor neuron health using correlative light and electron microscopy, electron tomography, and electrophysiology. We show that ectopic expression of wild-type or ALS-associated human FUS impairs synaptic vesicle docking at neuromuscular junctions. ALS-associated FUS led to the emergence of a population of large, electron-dense, and filament-filled endosomes. Electrophysiological recording revealed reduced transmission from motor neurons to muscles. Together, these results suggest a pathological effect of ALS-causing FUS at synaptic structure and function organization. KW - C. elegans KW - fused in sarcoma KW - amyotrophic lateral sclerosis KW - uper-resolution array tomography KW - electron tomography KW - neuromuscular junction Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230662 VL - 9 ER - TY - JOUR A1 - Kramer, Susanne A1 - Meyer-Natus, Elisabeth A1 - Stigloher, Christian A1 - Thoma, Hanna A1 - Schnaufer, Achim A1 - Engstler, Markus T1 - Parallel monitoring of RNA abundance, localization and compactness with correlative single molecule FISH on LR White embedded samples JF - Nucleic Acids Research N2 - Single mRNA molecules are frequently detected by single molecule fluorescence in situ hybridization (smFISH) using branched DNA technology. While providing strong and background-reduced signals, the method is inefficient in detecting mRNAs within dense structures, in monitoring mRNA compactness and in quantifying abundant mRNAs. To overcome these limitations, we have hybridized slices of high pressure frozen, freeze-substituted and LR White embedded cells (LR White smFISH). mRNA detection is physically restricted to the surface of the resin. This enables single molecule detection of RNAs with accuracy comparable to RNA sequencing, irrespective of their abundance, while at the same time providing spatial information on RNA localization that can be complemented with immunofluorescence and electron microscopy, as well as array tomography. Moreover, LR White embedding restricts the number of available probe pair recognition sites for each mRNA to a small subset. As a consequence, differences in signal intensities between RNA populations reflect differences in RNA structures, and we show that the method can be employed to determine mRNA compactness. We apply the method to answer some outstanding questions related to trans-splicing, RNA granules and mitochondrial RNA editing in single-cellular trypanosomes and we show an example of differential gene expression in the metazoan Caenorhabditis elegans. KW - mRNA Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230647 VL - 49 IS - 3 ER - TY - JOUR A1 - Vogel, Sebastian A1 - Gossner, Martin M. A1 - Mergner, Ulrich A1 - Müller, Jörg A1 - Thorn, Simon T1 - Optimizing enrichment of deadwood for biodiversity by varying sun exposure and tree species: An experimental approach JF - Journal of Applied Ecology N2 - The enrichment of deadwood is essential for the conservation of saproxylic biodiversity in managed forests. However, existing strategies focus on a cost‐intensive increase of deadwood amount, while largely neglecting increasing deadwood diversity. Deadwood objects, that is logs and branches, from six tree species were experimentally sun exposed, canopy shaded and artificially shaded for 4 years, after which the alpha‐, beta‐ and gamma‐diversity of saproxylic beetles, wood‐inhabiting fungi and spiders were analysed. Analyses of beta‐diversity included the spatial distance between exposed deadwood objects. A random‐drawing procedure was used to identify the combination of tree species and sun exposure that yielded the highest gamma‐diversity at a minimum of exposed deadwood amount. In sun‐exposed plots, species numbers in logs were higher than in shaded plots for all taxa, while in branches we observed the opposite for saproxylic beetles. Tree species affected the species numbers only of saproxylic beetles and wood‐inhabiting fungi. The beta‐diversity of saproxylic beetles and wood‐inhabiting fungi among logs was influenced by sun exposure and tree species, but beta‐diversity of spiders by sun exposure only. For all saproxylic taxa recorded in logs, differences between communities increased with increasing spatial distance. A combination of canopy‐shaded Carpinus logs and sun‐exposed Populus logs resulted in the highest species numbers of all investigated saproxylic taxa among all possible combinations of tree species and sun‐exposure treatments. Synthesis and applications. We recommend incorporating the enrichment of different tree species and particularly the variation in sun exposure into existing strategies of deadwood enrichment. Based on the results of our study, we suggest to combine the logs of softwood broadleaf tree species (e.g. Carpinus, Populus), hardwood broadleaf tree species (e.g. Quercus) and coniferous tree species (e.g. Pinus) under different conditions of sun exposure and distribute them spatially in a landscape to maximize the beneficial effects on overall diversity. KW - broadleaf tree species KW - deadwood enrichment KW - forest conservation KW - forest management KW - saproxylic beetles KW - spiders KW - sun exposure KW - wood‐inhabiting fungi Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214614 VL - 57 IS - 10 SP - 2075 EP - 2085 ER - TY - JOUR A1 - Leal, Andrea Zurita A1 - Schwebs, Marie A1 - Briggs, Emma A1 - Weisert, Nadine A1 - Reis, Helena A1 - Lemgruber, Leondro A1 - Luko, Katarina A1 - Wilkes, Jonathan A1 - Butter, Falk A1 - McCulloch, Richard A1 - Janzen, Christian J. T1 - Genome maintenance functions of a putative Trypanosoma brucei translesion DNA polymerase include telomere association and a role in antigenic variation JF - Nucleic Acids Research N2 - Maintenance of genome integrity is critical to guarantee transfer of an intact genome from parent to off-spring during cell division. DNA polymerases (Pols) provide roles in both replication of the genome and the repair of a wide range of lesions. Amongst replicative DNA Pols, translesion DNA Pols play a particular role: replication to bypass DNA damage. All cells express a range of translesion Pols, but little work has examined their function in parasites, including whether the enzymes might contribute to host-parasite interactions. Here, we describe a dual function of one putative translesion Pol in African trypanosomes, which we now name TbPolIE. Previously, we demonstrated that TbPolIE is associated with telomeric sequences and here we show that RNAi-mediated depletion of TbPolIE transcripts results in slowed growth, altered DNA content, changes in cell morphology, and increased sensitivity to DNA damaging agents. We also show that TbPolIE displays pronounced localization at the nuclear periphery, and that its depletion leads to chromosome segregation defects and increased levels of endogenous DNA damage. Finally, we demonstrate that TbPolIE depletion leads to deregulation of telomeric variant surface glycoprotein genes, linking the function of this putative translesion DNA polymerase to host immune evasion by antigenic variation. KW - cross-link repair KW - cell cycle KW - gene expression KW - low fidelity KW - replication KW - bypass KW - theta KW - reveals KW - binding Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230579 VL - 48 IS - 17 ER - TY - JOUR A1 - Floren, Andreas A1 - von Rintelen, Thomas A1 - Herbert, Paul D. N. A1 - de Araujo, Bruno Cancian A1 - Schmidt, Stefan A1 - Balke, Michael A1 - Narakusumo, Raden Pramesa A1 - Peggie, Djunijanti A1 - Ubaidillah, Rosichon A1 - von Rintelen, Kristina A1 - Müller, Tobias T1 - Integrative ecological and molecular analysis indicate high diversity and strict elevational separation of canopy beetles in tropical mountain forests JF - Scientific Reports N2 - Tropical mountain forests contribute disproportionately to terrestrial biodiversity but little is known about insect diversity in the canopy and how it is distributed between tree species. We sampled tree-specific arthropod communities from 28 trees by canopy fogging and analysed beetle communities which were first morphotyped and then identified by their DNA barcodes. Our results show that communities from forests at 1100 and 1700 m a.s.l. are almost completely distinct. Diversity was much lower in the upper forest while community structure changed from many rare, less abundant species to communities with a pronounced dominance structure. We also found significantly higher beta-diversity between trees at the lower than higher elevation forest where community similarity was high. Comparisons on tree species found at both elevations reinforced these results. There was little species overlap between sites indicating limited elevational ranges. Furthermore, we exploited the advantage of DNA barcodes to patterns of haplotype diversity in some of the commoner species. Our results support the advantage of fogging and DNA barcodes for community studies and underline the need for comprehensive research aimed at the preservation of these last remaining pristine forests. KW - beta-diversity KW - community data KW - gradients KW - insects KW - hypthesis KW - evolution KW - passes KW - ants Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230565 VL - 10 ER - TY - JOUR A1 - Matthes, Niels A1 - Diers, Johannes A1 - Schlegel, Nicolas A1 - Hankir, Mohammed A1 - Haubitz, Imme A1 - Germer, Christoph-Thomas A1 - Wiegering, Armin T1 - Validation of MTL30 as a quality indicator for colorectal surgery JF - PLoS One N2 - Background Valid indicators are required to measure surgical quality. These ideally should be sensitive and selective while being easy to understand and adjust. We propose here the MTL30 quality indicator which takes into account 30-day mortality, transfer within 30 days, and a length of stay of 30 days as composite markers of an uneventful operative/postoperative course. Methods Patients documented in the StuDoQ|Colon and StuDoQ|Rectal carcinoma register of the German Society for General and Visceral Surgery (DGAV) were analyzed with regard to the effects of patient and tumor-related risk factors as well as postoperative complications on the MTL30. Results In univariate analysis, the MTL30 correlated significantly with patient and tumor-related risk factors such as ASA score (p<0.001), age (p<0.001), or UICC stage (p<0.001). There was a high sensitivity for the postoperative occurrence of complications such as re-operations (p<0.001) or subsequent bleeding (p<0.001), as well as a significant correlation with the CDC classification (p<0.001). In multivariate analysis, patient-related risk factors and postoperative complications significantly increased the odds ratio for a positive MTL30. A negative MTL30 showed a high specify for an uneventful operative and postoperative course. Conclusion The MTL30 is a valid indicator of colorectal surgical quality. KW - surgical care KW - discharge definition KW - definition KW - mortality KW - pancreatectomy KW - complications KW - superior KW - capture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230530 VL - 15 IS - 8 ER - TY - JOUR A1 - Thorn, Simon A1 - Chao, Anne A1 - Georgiev, Konstadin B. A1 - Müller, Jörg A1 - Bässler, Claus A1 - Campbell, John L. A1 - Jorge, Castro A1 - Chen, Yan-Han A1 - Choi, Chang-Yong A1 - Cobb, Tyler P. A1 - Donato, Daniel C. A1 - Durska, Ewa A1 - Macdonald, Ellen A1 - Feldhaar, Heike A1 - Fontaine, Jospeh B. A1 - Fornwalt, Paula J. A1 - Hernández Hernández, Raquel María A1 - Hutto, Richard L. A1 - Koivula, Matti A1 - Lee, Eun-Jae A1 - Lindenmayer, David A1 - Mikusinski, Grzegorz A1 - Obrist, Martin K. A1 - Perlík, Michal A1 - Rost, Josep A1 - Waldron, Kaysandra A1 - Wermelinger, Beat A1 - Weiß, Ingmar A1 - Zmihorski, Michal A1 - Leverkus, Alexandro B. T1 - Estimating retention benchmarks for salvage logging to protect biodiversity JF - Nature Communications N2 - Forests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. We apply a mixed rarefaction/extrapolation approach to a global multi-taxa dataset from disturbed forests, including birds, plants, insects and fungi, to close this gap. We find that 757% (mean +/- SD) of a naturally disturbed area of a forest needs to be left unlogged to maintain 90% richness of its unique species, whereas retaining 50% of a naturally disturbed forest unlogged maintains 73 +/- 12% of its unique species richness. These values do not change with the time elapsed since disturbance but vary considerably among taxonomic groups. Salvage logging has become a common practice to gain economic returns from naturally disturbed forests, but it could have considerable negative effects on biodiversity. Here the authors use a recently developed statistical method to estimate that ca. 75% of the naturally disturbed forest should be left unlogged to maintain 90% of the species unique to the area. KW - natural disturbance KW - bird communities KW - forest KW - management KW - beetle KW - conservation KW - windthrow KW - diversity KW - impact KW - fire Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230512 VL - 11 ER - TY - JOUR A1 - Groma, Michaela A1 - Horst, Sarah A. A1 - Das, Sudip A1 - Huettel, Bruno A1 - Klepsch, Maximilian A1 - Rudel, Thomas A1 - Medina, Eva A1 - Fraunholz, Martin T1 - Identification of a Novel LysR-Type Transcriptional Regulator in Staphylococcus aureus That Is Crucial for Secondary Tissue Colonization during Metastatic Bloodstream Infection JF - mbio N2 - Staphylococcus aureus is a common cause of bacteremia that can lead to severe complications once the bacteria exit the bloodstream and establish infection in secondary organs. Despite its clinical relevance, little is known about the bacterial factors facilitating the development of these metastatic infections. Here, we used an S. aureus transposon mutant library coupled to transposon insertion sequencing (Tn-Seq) to identify genes that are critical for efficient bacterial colonization of secondary organs in a murine model of metastatic bloodstream infection. Our transposon screen identified a LysR-type transcriptional regulator (LTTR), which was required for efficient colonization of secondary organs such as the kidneys in infected mice. The critical role of LTTR in secondary organ colonization was confirmed using an isogenic mutant deficient in the expression of LTTR. To identify the set of genes controlled by LTTR, we used an S. aureus strain carrying the LTTR gene in an inducible expression plasmid. Gene expression analysis upon induction of LTTR showed increased transcription of genes involved in branched-chain amino acid biosynthesis, a methionine sulfoxide reductase, and a copper transporter as well as decreased transcription of genes coding for urease and components of pyrimidine nucleotides. Furthermore, we show that transcription of LTTR is repressed by glucose, is induced under microaerobic conditions, and required trace amounts of copper ions. Our data thus pinpoints LTTR as an important element that enables a rapid adaptation of S. aureus to the changing host microenvironment. IMPORTANCE Staphylococcus aureus is an important pathogen that can disseminate via the bloodstream and establish metastatic infections in distant organs. To achieve a better understanding of the bacterial factors facilitating the development of these metastatic infections, we used in this study a Staphylococcus aureus transposon mutant library in a murine model of intravenous infection, where bacteria first colonize the liver as the primary infection site and subsequently progress to secondary sites such as the kidney and bones. We identified a novel LysR-type transcriptional regulator (LTTR), which was specifically required by S. aureus for efficient colonization of secondary organs. We also determined the transcriptional activation as well as the regulon of LTTR, which suggests that this regulator is involved in the metabolic adaptation of S. aureus to the host microenvironment found in secondary infection sites. KW - Staphylococcus aureus KW - metabolic adaptation KW - secondary site infection KW - transcriptional regulation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230473 VL - 11 IS - 4 ER - TY - JOUR A1 - Römer, Daniela A1 - Cosarinsky, Marcela I. A1 - Roces, Flavio T1 - Selection and spatial arrangement of building materials during the construction of nest turrets by grass-cutting ants JF - Royal Society Open Science N2 - Ants build complex nest structures by reacting to simple, local stimuli. While underground nests result from the space generated by digging, some leaf- and grass-cutting ants also construct conspicuous aboveground turrets around nest openings. We investigated whether the selection of specific building materials occurs during turret construction in Acromyrmex fracticornis grass-cutting ants, and asked whether single building decisions at the beginning can modify the final turret architecture. To quantify workers' material selection, the original nest turret was removed and a choice between two artificial building materials, thin and thick sticks, was offered for rebuilding. Workers preferred thick sticks at the very beginning of turret construction, showed varying preferences thereafter, and changed to prefer thin sticks for the upper, final part of the turret, indicating that they selected different building materials over time to create a stable structure. The impact of a single building choice on turret architecture was evaluated by placing artificial beams that divided a colony's nest entrance at the beginning of turret rebuilding. Splitting the nest entrance led to the self-organized construction of turrets with branched galleries ending in multiple openings, showing that the spatial location of a single building material can strongly influence turret morphology. KW - collective building KW - behavioural plasticity KW - Acromyrmex fracticornis KW - quantitative stigmergy KW - self-organization KW - leaf-cutting ants Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230458 VL - 7 ER - TY - JOUR A1 - Whisnant, Adam W. A1 - Jürges, Christopher S. A1 - Hennig, Thomas A1 - Wyler, Emanuel A1 - Prusty, Bhupesh A1 - Rutkowski, Andrzej J. A1 - L'hernault, Anne A1 - Djakovic, Lara A1 - Göbel, Margarete A1 - Döring, Kristina A1 - Menegatti, Jennifer A1 - Antrobus, Robin A1 - Matheson, Nicholas J. A1 - Künzig, Florian W. H. A1 - Mastrobuoni, Guido A1 - Bielow, Chris A1 - Kempa, Stefan A1 - Liang, Chunguang A1 - Dandekar, Thomas A1 - Zimmer, Ralf A1 - Landthaler, Markus A1 - Grässer, Friedrich A1 - Lehner, Paul J. A1 - Friedel, Caroline C. A1 - Erhard, Florian A1 - Dölken, Lars T1 - Integrative functional genomics decodes herpes simplex virus 1 JF - Nature Communications N2 - The predicted 80 open reading frames (ORFs) of herpes simplex virus 1 (HSV-1) have been intensively studied for decades. Here, we unravel the complete viral transcriptome and translatome during lytic infection with base-pair resolution by computational integration of multi-omics data. We identify a total of 201 transcripts and 284 ORFs including all known and 46 novel large ORFs. This includes a so far unknown ORF in the locus deleted in the FDA-approved oncolytic virus Imlygic. Multiple transcript isoforms expressed from individual gene loci explain translation of the vast majority of ORFs as well as N-terminal extensions (NTEs) and truncations. We show that NTEs with non-canonical start codons govern the subcellular protein localization and packaging of key viral regulators and structural proteins. We extend the current nomenclature to include all viral gene products and provide a genome browser that visualizes all the obtained data from whole genome to single-nucleotide resolution. Here, using computational integration of multi-omics data, the authors provide a detailed transcriptome and translatome of herpes simplex virus 1 (HSV-1), including previously unidentified ORFs and N-terminal extensions. The study also provides a HSV-1 genome browser and should be a valuable resource for further research. KW - infected-cell protein KW - messenger RNA KW - binding protein KW - type 1 KW - identification KW - ICP27 KW - translation KW - expression KW - sequence KW - domain Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229884 VL - 11 ER - TY - THES A1 - Goos, Carina T1 - Nuclear periphery granules of trypanosomes - A characterization of composition and function T1 - Nuclear periphery granules in Trypanosomen - Eine Charakterisierung in Komposition und Funktion N2 - The nuclear envelope serves as important mRNA surveillance system. In yeast and humans, several control mechanisms act in parallel to prevent nuclear export of unprocessed mRNAs. However, trypanosomes lack homologues to most of the proteins involved. In addition, gene expression in trypanosomes relies almost completely on post-transcriptional regulation as they transcribe mRNAs as long polycistrons, which are subsequently processed into individual mRNA molecules by trans-splicing. As trans-splicing is not error-free, unspliced mRNAs may be recognized and prevented from reaching the cytoplasm by a yet unknown mechanism. When trans-splicing is inhibited in trypanosomes, the formation of a novel RNA granule type at the cytoplasmic periphery of the nucleus, so called nuclear periphery granules (NPGs) was previously observed. To identify potential regulators of nuclear export control, changes in protein localization which occur when trans-splicing is inhibited, were globally analyzed during this work. For this, trypanosome nuclei were purified under conditions maintaining NPG attachment to the nucleus, in the absence and presence of trans-splicing. Mass spectrometry analyses identified 128 proteins which are specifically enriched in nuclear preparations of cells inhibited for trans-splicing. Amongst them are proteins, which change their localization to the nucleus or to the nuclear pores as well as many proteins that move into NPGs. Some of these proteins are promising candidates for nuclear export control proteins, as the changes in localization (to the nucleus or nuclear pores) were specific to the accumulation of unspliced mRNAs. The NPG proteome almost exclusively contains proteins involved in mRNA metabolism, mostly unique to trypanosomes, notably major translation initiation factors were absent. These data indicate that NPGs are RNP complexes which have started or completed nuclear export, but not yet entered translation. As a byproduct of these proteomic studies, a high-quality dataset of the yet unknown T. brucei nuclear proteome is provided, closing an important gap in knowledge to study trypanosome biology, in particular nuclear related processes. NPGs were characterized in more detail by microscopy. The granules are cytoplasmic and present in at least two different trypanosome life cycle stages. There are at least two distinct granule subsets, with differences in protein composition. A closer analysis of NPGs by electron microscopy revealed that the granules are electron dense structures, which are connected to nuclear pores by string-like structures. In order to approach the function of NPGs, on the one hand, the hypothesis that NPGs might be related to perinuclear germ granules of adult gonads of C. elegans was tested: we found no relation between the two granule types. On the other hand, initial single molecule mRNA FISH experiments performed in trypanosomes showed no accumulation of unspliced transcripts in NPGs, arguing against an involvement of the granules in mRNA quality control. N2 - Die Kernhülle um den Zellkern dient als wichtiges mRNA-Überwachungssystem in Eukaryoten. Bei Hefen und Menschen wirken dabei beispielsweise mehrere Kontrollmechanismen parallel, um den Export von unverarbeiteten mRNAs aus dem Kern heraus zu verhindern. Trypanosomen fehlen jedoch Homologe zu den Meisten hierbei beteiligten Proteinen. Außerdem basiert Genexpression in Trypanosomen fast ausschließlich auf posttranskriptioneller Kontrolle, da die Parasiten mRNAs als lange Polycistrons transkribieren, die anschließend durch Transspleißen zu einzelnen mRNA-Molekülen verarbeitet werden. Da der Prozess des Transspleißen nicht fehlerfrei zu sein scheint, gibt es möglicherweise einen noch unbekannten Mechanismus, der nicht gespleißte mRNAs erkennt und diese daran hindert, das Zytoplasma zu erreichen. Unter Bedingungen, in denen Transspleißen in Trypanosomen blockiert ist, konnte eine neue Art von RNA-Granula an der zytoplasmatischen Peripherie des Zellkerns beobachtet werden, sogenannte Nuclear Periphery Granules (NPGs). Um potentielle Regulatoren einer Kontrolle des mRNA-Exports zu identifizieren, wurde während dieser Arbeit umfassend analysiert, inwieweit sich die Lokalisation von Proteinen ändert, wenn Transspleißen gehemmt wird. Zu diesem Zweck wurden Zellkerne von Trypanosomen unter Bedingungen aufgereinigt, bei denen die Bindung der NPGs an den Zellkern in Abwesenheit und Gegenwart von Transspleißen erhalten blieb. Mit Hilfe von massen-spektrometrischen Analysen konnten 128 Proteine identifiziert werden, die spezifisch in den Kernpräparaten von Zellen angereichert sind, in denen Transspleißen blockiert ist. Darunter befinden sich Proteine, die ihre Lokalisation in den Kern hinein oder zu den Kernporen hin verändern, sowie viele Proteine, die sich in NPGs bewegen. Einige dieser Proteine stellen vielversprechende Kandidaten für eine potenzielle Rolle in der Kernexportkontrolle dar, da die Veränderungen in der Lokalisation (zum Kern oder zu den Kernporen) spezifisch für die Akkumulation von nicht gespleißten mRNAs waren. Das hier erarbeitete NPG-Proteom enthält fast ausschließlich Proteine, die am mRNA-Metabolismus beteiligt sind und nur in Trypanosomen vorkommen. Insbesondere fehlen im NPG-Proteom wichtige Translationsinitiationsfaktoren. Die Daten zeigen, dass NPGs RNP-Komplexe sind, die den Export aus dem Zellkern bereits begonnen oder abgeschlossen haben, aber noch nicht mit dem Translationsprozess begonnen haben. Als Nebenprodukt dieser proteomischen Analyse, kann ein qualitativ hochwertiger Datensatz des noch unbekannten Kernproteoms von T. brucei bereitgestellt werden. Damit wird eine wichtige Wissenslücke bei der Forschung zur Trypanosomenbiologie, insbesondere zu nuklearen Prozessen geschlossen. Im Rahmen dieser Arbeit wurden außerdem NPGs anhand mikroskopischer Untersuchungen detaillierter charakterisiert. Die Granula sind zytoplasmatisch und liegen in mindestens zwei verschiedenen Lebenszyklusstadien von Trypanosomen vor. Es gibt mindestens zwei Untergruppen der Granula mit Unterschieden in der Proteinzusammensetzung. Eine genauere elektronenmikroskopische Analyse ergab, dass es sich bei NPGs um elektronendichte Strukturen handelt, die durch fadenartige Strukturen mit den Kernporen verbunden sind. Um mehr über die potenzielle Funktion von NPGs herauszufinden, wurde zum einen die Hypothese untersucht, dass NPGs mit perinuklearen Keimgranula adulter Gonaden in C. elegans verwandt sind: Es konnte keine Beziehung zwischen den beiden Granulatypen gefunden werden. Zum anderen zeigten erste Experimente mittels Einzelmolekül-mRNA-FISH in Trypanosomen keine Akkumulation von ungespleißten Transkripten in NPGs, was gegen eine Beteiligung an mRNA-Qualitätskontrollmechanismen spricht. KW - Trypanosoma brucei KW - Kinetoplastida KW - Rnsstoffwechsel KW - Nuclear periphery granules KW - RNA granules KW - Nuclear export control KW - Trypanosomes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234368 ER - TY - JOUR A1 - Roth, Nicolas A1 - Zoder, Sebastian A1 - Zaman, Assad Ali A1 - Thorn, Simon A1 - Schmidl, Jürgen T1 - Long‐term monitoring reveals decreasing water beetle diversity, loss of specialists and community shifts over the past 28 years JF - Insect Conservation and Diversity N2 - Lentic freshwater organisms are influenced by a multitude of factors, including geomorphology, hydrology, anthropogenic impacts and climate change. Organisms that depend on patchy resources such as water beetles may also be sensitive to anthropogenic habitat degradation, like pollution, eutrophication, water level or management alteration. To assess composition and ecological trends in the water beetle communities of Central Europe, we sampled water beetles (Dytiscidae, Haliplidae, Noteridae) in 33 water bodies in Southern Germany from 1991 to 2018. We used manual, time‐standardised capture during three periods: between 1991 and 1995, 2007 and 2008, and 2017 and 2018. During the 28‐year survey period, we captured a total of 81 species. We found annual declines in both species number (ca −1%) and abundance (ca −2%). Also, community composition showed significant changes over time. The significant impact of pH on the community composition suggests that the recorded changes through time partly reflect natural succession processes. However, a pronounced decline of beetle species belonging to the moor‐related beetle associations indicated that Central European water beetles are also threatened by non‐successional factors, including desiccation, increased nitrogen input and/or mineralisation, and the loss of specific habitats. This trend to physiographical homogenisation resulted in corresponding community composition shifts. To effectively protect endangered species, conservation strategies need to be aimed at regularly creating new water bodies with mineralic bottom substratum, and maintenance of moor water bodies that represent late successional stages. KW - biodiversity KW - lentic inland water bodies KW - long‐term monitoring KW - time series KW - water beetles Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214905 VL - 13 IS - 2 SP - 140 EP - 150 ER - TY - JOUR A1 - Georgiev, Kostadin B. A1 - Chao, Anne A1 - Castro, Jorge A1 - Chen, Yan‐Han A1 - Choi, Chang‐Yong A1 - Fontaine, Joseph B. A1 - Hutto, Richard L. A1 - Lee, Eun‐Jae A1 - Müller, Jörg A1 - Rost, Josep A1 - Żmihorski, Michal A1 - Thorn, Simon T1 - Salvage logging changes the taxonomic, phylogenetic and functional successional trajectories of forest bird communities JF - Journal of Applied Ecology N2 - Salvage logging following natural disturbances may alter the natural successional trajectories of biological communities by affecting the occurrences of species, functional groups and evolutionary lineages. However, few studies have examined whether dissimilarities between bird communities of salvaged and unsalvaged forests are more pronounced for rare species, functional groups and evolutionary lineages than for their more common counterparts. We compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, covering a 17‐year period following wildfire or windstorm disturbances and subsequent salvage logging. We tested whether dissimilarities based on non‐shared species, functional groups and evolutionary lineages (a) decreased or increased over time and (b) the responses of rare, common and dominant species varied, by using a unified statistical framework based on Hill numbers and null models. We found that dissimilarities between bird communities caused by salvage logging persisted over time for rare, common and dominant species, evolutionary lineages and for rare functional groups. Dissimilarities of common and dominant functional groups increased 14 years post disturbance. Salvage logging led to significantly larger dissimilarities than expected by chance. Functional dissimilarities between salvaged and unsalvaged sites were lower compared to taxonomic and phylogenetic dissimilarities. In general, dissimilarities were highest for rare, followed by common and dominant species. Synthesis and applications. Our research demonstrates that salvage logging did not decrease dissimilarities of bird communities over time and taxonomic, functional and phylogenetic dissimilarities persisted for over a decade. We recommend resource managers and decision makers to reserve portions of disturbed forest to enable unmanaged post‐disturbance succession of bird communities, particularly to conserve rare species found in unsalvaged disturbed forests. KW - biodiversity KW - breeding season KW - forest management KW - harvesting KW - Hill numbers KW - natural disturbance KW - successional trajectory Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214887 VL - 57 IS - 6 SP - 1103 EP - 1112 ER - TY - JOUR A1 - Kühnisch, Jirko A1 - Herbst, Christopher A1 - Al‐Wakeel‐Marquard, Nadya A1 - Dartsch, Josephine A1 - Holtgrewe, Manuel A1 - Baban, Anwar A1 - Mearini, Giulia A1 - Hardt, Juliane A1 - Kolokotronis, Konstantinos A1 - Gerull, Brenda A1 - Carrier, Lucie A1 - Beule, Dieter A1 - Schubert, Stephan A1 - Messroghli, Daniel A1 - Degener, Franziska A1 - Berger, Felix A1 - Klaassen, Sabine T1 - Targeted panel sequencing in pediatric primary cardiomyopathy supports a critical role of TNNI3 JF - Clinical Genetics N2 - The underlying genetic mechanisms and early pathological events of children with primary cardiomyopathy (CMP) are insufficiently characterized. In this study, we aimed to characterize the mutational spectrum of primary CMP in a large cohort of patients ≤18 years referred to a tertiary center. Eighty unrelated index patients with pediatric primary CMP underwent genetic testing with a panel‐based next‐generation sequencing approach of 89 genes. At least one pathogenic or probably pathogenic variant was identified in 30/80 (38%) index patients. In all CMP subgroups, patients carried most frequently variants of interest in sarcomere genes suggesting them as a major contributor in pediatric primary CMP. In MYH7, MYBPC3, and TNNI3, we identified 18 pathogenic/probably pathogenic variants (MYH7 n = 7, MYBPC3 n = 6, TNNI3 n = 5, including one homozygous (TNNI3 c.24+2T>A) truncating variant. Protein and transcript level analysis on heart biopsies from individuals with homozygous mutation of TNNI3 revealed that the TNNI3 protein is absent and associated with upregulation of the fetal isoform TNNI1. The present study further supports the clinical importance of sarcomeric mutation—not only in adult—but also in pediatric primary CMP. TNNI3 is the third most important disease gene in this cohort and complete loss of TNNI3 leads to severe pediatric CMP. KW - cardiomyopathy KW - genetics KW - pediatrics KW - sarcomere KW - TNNI3 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213958 VL - 96 IS - 6 SP - 549 EP - 559 ER - TY - JOUR A1 - Gupta, Shishir K. A1 - Srivastava, Mugdha A1 - Osmanoglu, Oezge A1 - Dandekar, Thomas T1 - Genome-wide inference of the Camponotus floridanus protein-protein interaction network using homologous mapping and interacting domain profile pairs JF - Scientific Reports N2 - Apart from some model organisms, the interactome of most organisms is largely unidentified. High-throughput experimental techniques to determine protein-protein interactions (PPIs) are resource intensive and highly susceptible to noise. Computational methods of PPI determination can accelerate biological discovery by identifying the most promising interacting pairs of proteins and by assessing the reliability of identified PPIs. Here we present a first in-depth study describing a global view of the ant Camponotus floridanus interactome. Although several ant genomes have been sequenced in the last eight years, studies exploring and investigating PPIs in ants are lacking. Our study attempts to fill this gap and the presented interactome will also serve as a template for determining PPIs in other ants in future. Our C. floridanus interactome covers 51,866 non-redundant PPIs among 6,274 proteins, including 20,544 interactions supported by domain-domain interactions (DDIs), 13,640 interactions supported by DDIs and subcellular localization, and 10,834 high confidence interactions mediated by 3,289 proteins. These interactions involve and cover 30.6% of the entire C. floridanus proteome. KW - interaction map KW - drosophila KW - identification KW - evolutionary KW - reliability KW - annotation KW - database KW - target KW - cycle Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229406 VL - 10 IS - 1 ER - TY - JOUR A1 - Lichthardt, Sven A1 - Wagner, Johanna A1 - Löb, Stefan A1 - Matthes, Niels A1 - Kastner, Caroline A1 - Anger, Friedrich A1 - Germer, Christoph-Thomas A1 - Wiegering, Armin T1 - Pathological complete response due to a prolonged time interval between preoperative chemoradiation and surgery in locally advanced rectal cancer: analysis from the German StuDoQ|Rectalcarcinoma registry JF - BMC Cancer N2 - Background Preoperative chemoradiotherapy is the recommended standard of care for patients with local advanced rectal cancer. However, it remains unclear, whether a prolonged time interval to surgery results in an increased perioperative morbidity, reduced TME quality or better pathological response. Aim of this study was to determine the time interval for best pathological response and perioperative outcome compared to current recommended interval of 6 to 8 weeks. Methods This is a retrospective analysis of the German StuDoQ|Rectalcarcinoma registry. Patients were grouped for the time intervals of "less than 6 weeks", "6 to 8 weeks", "8 to 10 weeks" and "more than 10 weeks". Primary endpoint was pathological response, secondary endpoint TME quality and complications according to Clavien-Dindo classification. Results Due to our inclusion criteria (preoperative chemoradiation, surgery in curative intention, M0), 1.809 of 9.560 patients were suitable for analysis. We observed a trend for increased rates of pathological complete response (pCR: ypT0ypN0) and pathological good response (pGR: ypT0-1ypN0) for groups with a prolonged time interval which was not significant. Ultimately, it led to a steady state of pCR (16.5%) and pGR (22.6%) in "8 to 10" and "more than 10" weeks. We were not able to observe any differences between the subgroups in perioperative morbidity, proportion of rectal extirpation (for cancer of the lower third) or difference in TME quality. Conclusion A prolonged time interval between neoadjuvant chemoradiation can be performed, as the rate of pCR seems to be increased without influencing perioperative morbidity. KW - Rectal cancer KW - Surgery KW - Radiochemotherapy KW - Time interval Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229334 VL - 20 IS - 1 ER - TY - JOUR A1 - Osman, Mohamed A1 - Stigloher, Christian A1 - Mueller, Martin J. A1 - Waller, Frank T1 - An improved growth medium for enhanced inoculum production of the plant growth-promoting fungus Serendipita indica JF - Plant Methods N2 - Background The plant endophytic fungus Serendipita indica colonizes roots of a wide range of plant species and can enhance growth and stress resistance of these plants. Due to its ease of axenic cultivation and its broad host plant range including the model plant Arabidopsis thaliana and numerous crop plants, it is widely used as a model fungus to study beneficial fungus-root interactions. In addition, it was suggested to be utilized for commercial applications, e.g. to enhance yield in barley and other species. To produce inoculum, S. indica is mostly cultivated in a complex Hill-Kafer medium (CM medium), however, growth in this medium is slow, and yield of chlamydospores, which are often used for plant root inoculation, is relatively low. Results We tested and optimized a simple vegetable juice-based medium for an enhanced yield of fungal inoculum. The described vegetable juice (VJ) medium is based on commercially available vegetable juice and is easy to prepare. VJ medium was superior to the currently used CM medium with respect to biomass production in liquid medium and hyphal growth on agar plates. Using solid VJ medium supplemented with sucrose (VJS), a high amount of chlamydospores developed already after 8 days of cultivation, producing significantly more spores than on CM medium. Use of VJ medium is not restricted to S. indica, as it also supported growth of two pathogenic fungi often used in plant pathology experiments: the ascomycete Fusarium graminearum, the causal agent of Fusarium head blight disease on wheat and barley, and Verticillium longisporum, the causal agent of verticillium wilt. Conclusions The described VJ medium is recommended for streamlined and efficient production of inoculum for the plant endophytic fungus Serendipita indica and might prove superior for the propagation of other fungi for research purposes. KW - Serendipita indica KW - Plant root endophyte KW - Inoculum production KW - Complex medium KW - Aspergillus medium KW - Vegetable juice KW - Plant growth promotion Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229186 VL - 16 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Bencurova, Elena A1 - Förster, Carola A1 - Dandekar, Thomas T1 - Modeling of shotgun sequencing of DNA plasmids using experimental and theoretical approaches JF - BMC Bioinformatics N2 - Background Processing and analysis of DNA sequences obtained from next-generation sequencing (NGS) face some difficulties in terms of the correct prediction of DNA sequencing outcomes without the implementation of bioinformatics approaches. However, algorithms based on NGS perform inefficiently due to the generation of long DNA fragments, the difficulty of assembling them and the complexity of the used genomes. On the other hand, the Sanger DNA sequencing method is still considered to be the most reliable; it is a reliable choice for virtual modeling to build all possible consensus sequences from smaller DNA fragments. Results In silico and in vitro experiments were conducted: (1) to implement and test our novel sequencing algorithm, using the standard cloning vectors of different length and (2) to validate experimentally virtual shotgun sequencing using the PCR technique with the number of cycles from 1 to 9 for each reaction. Conclusions We applied a novel algorithm based on Sanger methodology to correctly predict and emphasize the performance of DNA sequencing techniques as well as in de novo DNA sequencing and its further application in synthetic biology. We demonstrate the statistical significance of our results. KW - Shotgun method KW - Sanger sequencing KW - Virtual sequencing KW - Polymerase chain reaction KW - Gene expression vectors KW - Synthetic biology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229169 VL - 2020 ER - TY - JOUR A1 - Memmel, Simon A1 - Sisario, Dmitri A1 - Zimmermann, Heiko A1 - Sauer, Markus A1 - Sukhorukov, Vladimir L. A1 - Djuzenova, Cholpon S. A1 - Flentje, Michael T1 - FocAn: automated 3D analysis of DNA repair foci in image stacks acquired by confocal fluorescence microscopy JF - BMC Bioinformatics N2 - Background Phosphorylated histone H2AX, also known as gamma H2AX, forms mu m-sized nuclear foci at the sites of DNA double-strand breaks (DSBs) induced by ionizing radiation and other agents. Due to their specificity and sensitivity, gamma H2AX immunoassays have become the gold standard for studying DSB induction and repair. One of these assays relies on the immunofluorescent staining of gamma H2AX followed by microscopic imaging and foci counting. During the last years, semi- and fully automated image analysis, capable of fast detection and quantification of gamma H2AX foci in large datasets of fluorescence images, are gradually replacing the traditional method of manual foci counting. A major drawback of the non-commercial software for foci counting (available so far) is that they are restricted to 2D-image data. In practice, these algorithms are useful for counting the foci located close to the midsection plane of the nucleus, while the out-of-plane foci are neglected. Results To overcome the limitations of 2D foci counting, we present a freely available ImageJ-based plugin (FocAn) for automated 3D analysis of gamma H2AX foci in z-image stacks acquired by confocal fluorescence microscopy. The image-stack processing algorithm implemented in FocAn is capable of automatic 3D recognition of individual cell nuclei and gamma H2AX foci, as well as evaluation of the total foci number per cell nucleus. The FocAn algorithm consists of two parts: nucleus identification and foci detection, each employing specific sequences of auto local thresholding in combination with watershed segmentation techniques. We validated the FocAn algorithm using fluorescence-labeled gamma H2AX in two glioblastoma cell lines, irradiated with 2 Gy and given up to 24 h post-irradiation for repair. We found that the data obtained with FocAn agreed well with those obtained with an already available software (FoCo) and manual counting. Moreover, FocAn was capable of identifying overlapping foci in 3D space, which ensured accurate foci counting even at high DSB density of up to similar to 200 DSB/nucleus. Conclusions FocAn is freely available an open-source 3D foci analyzer. The user-friendly algorithm FocAn requires little supervision and can automatically count the amount of DNA-DSBs, i.e. fluorescence-labeled gamma H2AX foci, in 3D image stacks acquired by laser-scanning microscopes without additional nuclei staining. KW - DNA double-strand breaks KW - ImageJ plugin KW - gamma H2AX-foci KW - Automated analysis KW - Ionizing radiation KW - Open-source tool KW - Radiation biology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229023 VL - 21 ER - TY - JOUR A1 - Goméz-H, Laura A1 - Felipe-Medina, Natalia A1 - Sánchez-Martín, Manuel A1 - Davies, Owen R. A1 - Ramos, Isabel A1 - García-Tuñón, Ignacio A1 - de Rooij, Dirk G. A1 - Dereli, Ihsan A1 - Tóth, Attila A1 - Barbero, José Luis A1 - Benavente, Ricardo A1 - Llano, Elena A1 - Pendas, Alberto M. T1 - C14ORF39/SIX6OS1 is a constituent of the synaptonemal complex and is essential for mouse fertility JF - Nature Communications N2 - Meiotic recombination generates crossovers between homologous chromosomes that are essential for genome haploidization. The synaptonemal complex is a ‘zipper’-like protein assembly that synapses homologue pairs together and provides the structural framework for processing recombination sites into crossovers. Humans show individual differences in the number of crossovers generated across the genome. Recently, an anonymous gene variant in C14ORF39/SIX6OS1 was identified that influences the recombination rate in humans. Here we show that C14ORF39/SIX6OS1 encodes a component of the central element of the synaptonemal complex. Yeast two-hybrid analysis reveals that SIX6OS1 interacts with the well-established protein synaptonemal complex central element 1 (SYCE1). Mice lacking SIX6OS1 are defective in chromosome synapsis at meiotic prophase I, which provokes an arrest at the pachytene-like stage and results in infertility. In accordance with its role as a modifier of the human recombination rate, SIX6OS1 is essential for the appropriate processing of intermediate recombination nodules before crossover formation. KW - Chromosomes KW - Meiosis KW - Spermatogenesis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165907 VL - 7 ER - TY - THES A1 - Jessen, Christina T1 - NRF2 links antioxidant and immune-relevant features in melanoma T1 - NRF2 verknüpft antioxidative und immunrelevante Eigenschaften im Melanom N2 - The transcription factor NRF2 is considered as the master regulator of cytoprotective and ROS-detoxifying gene expression. Due to their vulnerability to accumulating reactive oxygen species, melanomas are dependent on an efficient oxidative stress response, but to what extent melanomas rely on NRF2 is only scarcely investigated so far. In tumor entities harboring activating mutations of NRF2, such as lung adenocarcinoma, NRF2 activation is closely connected to therapy resistance. In melanoma, activating mutations are rare and triggers and effectors of NRF2 are less well characterized. This work revealed that NRF2 is activated by oncogenic signaling, cytokines and pro-oxidant triggers, released cell-autonomously or by the tumor microenvironment. Moreover, silencing of NRF2 significantly reduced melanoma cell proliferation and repressed well-known NRF2 target genes, indicating basal transcriptional activity of NRF2 in melanoma. Transcriptomic analysis showed a large set of deregulated gene sets, besides the well-known antioxidant effectors. NRF2 suppressed the activity of MITF, a marker for the melanocyte lineage, and induced expression of epidermal growth factor receptor (EGFR), thereby stabilizing the dedifferentiated melanoma phenotype and limiting pigmentation markers and melanoma-associated antigens. In general, the dedifferentiated melanoma phenotype is associated with a reduced tumor immunogenicity. Furthermore, stress-inducible cyclooxygenase 2 (COX2) expression, a crucial immune-modulating gene, was regulated by NRF2 in an ATF4-dependent manner. Only in presence of both transcription factors was COX2 robustly induced by H2O2 or TNFα. COX2 catalyzes the first step of the prostaglandin E2 (PGE2) synthesis, which was described to be associated with tumor immune evasion and reduction of the innate immune response. In accordance with these potentially immune-suppressive features, immunocompetent mice injected with NRF2 knockout melanoma cells had a strikingly longer tumor-free survival compared to NRF2-proficient cells. In line with the in vitro data, NRF2-deficient tumors showed suppression of COX2 and induction of MITF. Furthermore, transcriptomic analyses of available tumors revealed a strong induction of genes belonging to the innate immune response, such as RSAD2 and IFIH1. The expression of these genes strongly correlated with immune evasion parameters in human melanoma datasets and NRF2 activation or PGE2 supplementation limited the innate immune response in vitro. In summary, the stress dependent NRF2 activation stabilizes the dedifferentiated melanoma phenotype and facilitates the synthesis of PGE2. As a result, NRF2 reduces gene expression of the innate immune response and promotes the generation of an immune-cold tumor microenvironment. Therefore, NRF2 not only elevated the ROS resilience, but also strongly contributed to tumor growth, maintenance, and immune control in cutaneous melanoma. N2 - Der Transkriptionsfaktor NRF2 gilt als Masterregulator der antioxidativen Zellantwort. Im Melanom ist die Rolle von NRF2 bisher nur wenig untersucht worden, obwohl das Melanom anfällig für oxidativen Stress ist und somit eine besondere Abhängigkeit von antioxidativen Prozessen besteht. In Tumorentitäten mit NRF2 aktivierende Mutationen, wie z.B. dem Lungenadenokarzinom, ist die NRF2 Aktivierung mit einer Therapieresistenz verbunden. Allerdings sind diese aktivierenden Mutationen im Melanom selten und Mechanismen, die zu einer NRF2 Aktivierung führen, sind kaum bekannt. Die vorliegende Arbeit zeigt, dass NRF2 hier vor allem durch onkogene Signalwege, Zytokine und pro-oxidative Trigger aktiviert wird. Zudem verringerte die NRF2 Inhibierung die Zellproliferation und reduzierte die Expression von bekannten NRF2 Zielgenen. Dies weist darauf hin, dass die basale Transkriptionsaktivität von NRF2 im Melanom wichtig ist. Neben den bekannten Zielgenen waren außerdem eine Vielzahl von ROS-unabhängigen Gen-Sets dereguliert. Zum einen reduzierte NRF2 die Aktivität von MITF, dem melanozytären Lineage Marker und induzierte die Expression des epidermalen Wachstumsfaktorrezeptors, EGFR. Dadurch stabilisiert NRF2 den undifferenzierten Melanom-Phänotyp, welcher allgemein mit einer verminderten Expression von Pigmentierungsmarkern und Melanom-assoziierten Antigenen verbunden ist. Zum anderen regulierte NRF2 die Expression von Cyclooxygenase 2 (COX2), in Abhängigkeit von dem Transkriptionsfaktor ATF4. COX2 wurde basal und nach H2O2 oder TNFα Stimulation nur in Anwesenheit beider Transkriptionsfaktoren exprimiert. COX2 katalysiert die Prostaglandin E2 (PGE2) Synthese und es wurde beschrieben, dass hohe Konzentrationen an PGE2, sowohl die Immunevasion von Tumoren erleichtert als auch die angeborenen Immunantwort reduziert. In Übereinstimmung mit diesen potenziell immun-evasiven Eigenschaften zeigten immunkompetente Mäuse, denen NRF2-knockout Melanomzellen injiziert wurden, im Vergleich zu Kontrollzellen, ein deutlich längeres tumorfreies Überleben. Die NRF2-abhängige COX2 Erhöhung und MITF Hemmung, wurde zudem in den Maustumoren bestätigt. Darüber hinaus zeigten die NRF2-defizienten Tumore eine starke Induktion von Genen des angeborenen Immunsystems, wie z.B. RSAD2 und IFIH1. Die Expression dieser Gene korrelierte mit Immunevasionsparametern in Datensätzen des humanen Melanoms und eine NRF2 Aktivierung oder PGE2 Zugabe unterdrückte die Genexpression der angeborene Immunantwort bereits in vitro. Somit stabilisiert stress-induziertes NRF2 den undifferenzierten Melanom-Phänotyp und fördert die immunmodulierende PGE2 Produktion. Infolgedessen reduziert NRF2 die angeborene Immunantwort und unterstützt die Entstehung einer immun-suppressiven Tumormikroumgebung, welche das Tumorwachstum erleichtert. Die endogene NRF2 Aktivierung im Melanom fördert somit nicht nur die ROS-Resilienz, sondern auch die Tumoraufrechterhaltung und das Tumorwachstum im immunkompetenten Organismus. KW - Melanom KW - Oxidativer Stress KW - Genexpression KW - Krebsforschung KW - NRF2 KW - Antioxidantien KW - melanoma dedifferentiation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233495 ER - TY - THES A1 - Rüdenauer, Fabian T1 - Nutrition facts of pollen: nutritional quality and how it affects reception and perception in bees T1 - Nährwertinformationen von Pollen: Nährstoffzusammensetzung und wie diese sich auf Rezeption und Perzeption von Bienen auswirkt N2 - Nutrients belong to the key elements enabling life and influencing an organism’s fitness. The intake of nutrients in the right amounts and ratios can increase fitness; strong deviations from the optimal intake target can decrease fitness. Hence, the ability to assess the nutritional profile of food would benefit animals. To achieve this, they need the according nutrient receptors, the ability to interpret the receptor information via perceptive mechanisms, and the ability to adjust their foraging behavior accordingly. Additionally, eventually existing correlations between the nutrient groups and single nutrient compounds in food could help them to achieve this adjustment. A prominent interaction between food and consumer is the interaction between flowering plants (angiosperms) and animal pollinators. Usually both of the interacting partners benefit from this mutualistic interaction. Plants are pollinated while pollinators get a (most of the times) nutritional reward in form of nectar and/or pollen. As similar interactions between plants and animals seem to have existed even before the emergence of angiosperms, these interactions between insects and angiosperms very likely have co-evolved right from their evolutionary origin. Therefore, insect pollinators with the ability to assess the nutritional profile may have shaped the nutritional profile of plant species depending on them for their reproduction via selection pressure. In Chapter I of this thesis the pollen nutritional profile of many plant species was analyzed in the context of their phylogeny and their dependence on insect pollinators. In addition, correlations between the nutrients were investigated. While the impact of phylogeny on the pollen protein content was little, the mutual outcome of both of the studies included in this chapter is that protein content of pollen is mostly influenced by the plant’s dependence on insect pollinators. Several correlations found between nutrients within and between the nutrient groups could additionally help the pollinators to assess the nutrient profile of pollen. An important prerequisite for this assessment would be that the pollinators are able to differentiate between pollen of different plant species. Therefore, in Chapter II it was investigated whether bees have this ability. Specifically, it was investigated whether honeybees are able to differentiate between pollen of two different, but closely related plant species and whether bumblebees prefer one out of three pollen mixes, when they were fed with only one of them as larvae. Honeybees indeed were able to differentiate between the pollen species and bumblebees preferred one of the pollen mixes to the pollen mix they were fed as larvae, possibly due to its nutritional content. Therefore, the basis for pollen nutrient assessment is given in bees. However, there also was a slight preference for the pollen fed as larvae compared to another non-preferred pollen mix, at least hinting at the retention of larval memory in adult bumblebees. Chapter III looks into nutrient perception of bumblebees more in detail. Here it was shown that they are principally able to perceive amino acids and differentiate between them as well as different concentrations of the same amino acid. However, they do not seem to be able to assess the amino acid content in pollen or do not focus on it, but instead seem to focus on fatty acids, for which they could not only perceive concentration differences, but also were able to differentiate between. These findings were supported by feeding experiments in which the bumblebees did not prefer any of the pollen diets containing less or more amino acids but preferred pollen with less fatty acids. In no choice feeding experiments, bumblebees receiving a diet with high fatty acid content accepted undereating other nutrients instead of overeating fat, leading to increased mortality and the inability to reproduce. Hence, the importance of fat in pollen needs to be looked into further. In conclusion, this thesis shows that the co-evolution of flowering plants and pollinating insects could be even more pronounced than thought before. Insects do not only pressure the plants to produce high quality nectar, but also pressure those plants depending on insect pollination to produce high quality pollen. The reason could be the insects’ ability to receive and perceive certain nutrients, which enables them to forage selectively leading to a higher reproductive success of plants with a pollinator-suitable nutritional pollen profile. N2 - Nährstoffe gehören zu den zentralen Elementen, die das Leben an sich ermöglichen und die Fitness eines Organismus beeinflussen können. Nährstoffaufnahme in den richtigen Mengen und Verhältnissen kann die Fitness verbessern, starke Abweichungen von der optimalen Aufnahme können sie verschlechtern. Deshalb könnten Tiere von der Fähigkeit profitieren das Nährstoffprofil von Nahrung bewerten zu können. Dafür benötigten sie jedoch die passenden Nährstoffrezeptoren, die Fähigkeit die Rezeptorinformationen durch perzeptive Mechanismen zu interpretieren und ihr Sammelverhalten daran anzupassen. Eine zusätzliche Hilfe dabei könnten Korrelationen zwischen sowohl den Nährstoffgruppen als auch einzelnen Nährstoffen bieten. Eine bekannte Interaktion zwischen Nahrung und Konsument ist die zwischen Blühpflanzen (Angiospermen) und tierischen Bestäubern. Normalerweise profitieren beide Interaktionspartner von dieser mutualistischen Interaktion. Pflanzen werden bestäubt, während die Bestäuber eine (zumeist) nahrhafte Belohnung in Form von Nektar und/oder Pollen erhalten. Da ähnliche Interaktionen zwischen Pflanzen und Tieren vermutlich schon vor dem Auftreten der Angiospermen existierten, könnte sich diese Interaktion, im Speziellen mit Insekten, direkt vom evolutiven Startpunkt der Angiospermen aus koevolviert haben. Deshalb ist es möglich, dass Bestäuber mit der Fähigkeit das Nährstoffprofil von Pollen bewerten zu können, dieses bei von ihnen abhängigen Pflanzen durch Selektionsdruck formen konnten. Im Kapitel I dieser Thesis wurde das Nährstoffprofil von Pollen vieler Pflanzenarten im Kontext ihrer Phylogenie und ihrer Abhängigkeit von Insekten als Bestäubern analysiert. Außerdem wurden Korrelationen zwischen den Nährstoffen untersucht. Während die Phylogenie nur einen geringen Einfluss auf den Proteingehalt von Pollen haben könnte, ist der gemeinsame Nenner der beiden Studien in diesem Kapitel, dass der Proteingehalt des Pollens hauptsächlich von der Abhängigkeit der Pflanzen von Bestäubern bestimmt wird. Es wurden zudem einige Korrelationen sowohl in als auch zwischen den Nährstoffgruppen gefunden, die den Bestäubern helfen könnten das Nährstoffprofil von Pollen bewerten zu können. Eine wichtige Grundvoraussetzung für diese Bewertung wäre, dass die Bestäuber überhaupt dazu in der Lage sind zwischen Pollen von unterschiedlichen Pflanzenarten zu unterscheiden. Dies wird in Kapitel II behandelt, in dem untersucht wurde ob Honigbienen in der Lage sind zwischen Pollen zweier nah verwandter Pflanzenarten zu unterscheiden und ob Hummeln eine von drei Pollenmischungen bevorzugen, wenn sie nur mit einer davon als Larve in Kontakt kamen. Honigbienen war es tatsächlich möglich zwischen den Pollenarten zu unterscheiden und Hummeln bevorzugten eine bestimmte Pollenmischung gegenüber der, die sie als Larve erhalten hatten, möglicherweise aufgrund eines vorteilhaften Nährstoffprofils. Die Grundlage zur Nährstoffbewertung scheint bei Bienen also gegeben zu sein. Allerdings hatten die Hummeln auch eine leichte Präferenz für die Pollenmischung, die sie als Larve erhalten hatten gegenüber der dritten, nicht bevorzugten Pollenmischung, was zumindest darauf hindeuten könnte, dass Larvenerinnerungen bei erwachsenen Hummeln erhalten bleiben könnten. Kapitel III beschäftigt sich tiefergehend mit der Nährstoffwahrnehmung von Hummeln. Es wurde gezeigt, dass diese prinzipiell befähigt sind Aminosäuren wahrzunehmen als auch zwischen ihnen und verschiedenen Konzentrationen der gleichen Aminosäure zu unterscheiden. Allerdings scheinen sie entweder nicht in der Lage zu sein oder sich zumindest nicht darauf zu fokussieren den Aminosäuregehalt von Pollen zu bewerten, sondern sich eher auf Fettsäuren zu konzentrieren. Von diesen konnten sie nicht nur Konzentrationsunterschiede feststellen, sondern auch zwischen verschiedenen Fettsäuren im Pollen unterscheiden. Diese Ergebnisse wurden von denen in Fütterungsexperimenten gestützt, in denen die Hummeln gleiche Mengen von Pollen mit mehr oder weniger Aminosäuren aufnahmen, aber Pollen mit weniger Fettsäuren bevorzugten. In Experimenten, in denen die Hummeln keine Wahl hatten, nahmen die Hummeln mit einer Diät, die eine hohe Fettsäurekonzentration hatte, lieber in Kauf, dass sie zu wenig von den anderen Nährstoffen aufnahmen, als zu viel Fett, was zu einer erhöhten Mortalitätsrate und der Unfähigkeit sich zu reproduzieren führte. Deshalb sollten zukünftige Studien sich eingehender mit dem Fettsäuregehalt von Pollen beschäftigen. Zusammenfassend zeigt diese Thesis, dass die Koevolution von Pflanzen und bestäubenden Insekten ausgeprägter sein könnte, als bisher angenommen. Insekten setzen die Pflanzen nicht nur unter Druck qualitativ hochwertigen Nektar zu produzieren, sondern setzen vor allem auch die Pflanzen unter Druck, die von ihrer Bestäubung abhängig sind, qualitativ hochwertigen Pollen zu produzieren. Der Grund dafür könnte die Fähigkeit der Insekten sein, bestimmte Nährstoffe zu rezipieren und perzipieren und dann ihr Sammelverhalten so anzupassen, dass Pflanzen mit einem passenden Nährstoffprofil einen höheren Reproduktionserfolg haben. KW - Pollen KW - bumblebee*s KW - nutrients KW - nutrition KW - pollen KW - reception KW - perception KW - proboscis extension response KW - honeybee*s Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-212548 ER - TY - JOUR A1 - Bowler, Diana E. A1 - Bjorkman, Anne D. A1 - Dornelas, Maria A1 - Myers‐Smith, Isla H. A1 - Navarro, Laetitia M. A1 - Niamir, Aidin A1 - Supp, Sarah R. A1 - Waldock, Conor A1 - Winter, Marten A1 - Vellend, Mark A1 - Blowes, Shane A. A1 - Böhning‐Gaese, Katrin A1 - Bruelheide, Helge A1 - Elahi, Robin A1 - Antão, Laura H. A1 - Hines, Jes A1 - Isbell, Forest A1 - Jones, Holly P. A1 - Magurran, Anne E. A1 - Cabral, Juliano Sarmento A1 - Bates, Amanda E. T1 - Mapping human pressures on biodiversity across the planet uncovers anthropogenic threat complexes JF - People and Nature N2 - Climate change and other anthropogenic drivers of biodiversity change are unequally distributed across the world. Overlap in the distributions of different drivers have important implications for biodiversity change attribution and the potential for interactive effects. However, the spatial relationships among different drivers and whether they differ between the terrestrial and marine realm has yet to be examined. We compiled global gridded datasets on climate change, land‐use, resource exploitation, pollution, alien species potential and human population density. We used multivariate statistics to examine the spatial relationships among the drivers and to characterize the typical combinations of drivers experienced by different regions of the world. We found stronger positive correlations among drivers in the terrestrial than in the marine realm, leading to areas with high intensities of multiple drivers on land. Climate change tended to be negatively correlated with other drivers in the terrestrial realm (e.g. in the tundra and boreal forest with high climate change but low human use and pollution), whereas the opposite was true in the marine realm (e.g. in the Indo‐Pacific with high climate change and high fishing). We show that different regions of the world can be defined by Anthropogenic Threat Complexes (ATCs), distinguished by different sets of drivers with varying intensities. We identify 11 ATCs that can be used to test hypotheses about patterns of biodiversity and ecosystem change, especially about the joint effects of multiple drivers. Our global analysis highlights the broad conservation priorities needed to mitigate the impacts of anthropogenic change, with different priorities emerging on land and in the ocean, and in different parts of the world. KW - Anthropocene KW - biodiversity threats KW - direct drivers KW - global change Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213634 VL - 2 IS - 2 SP - 380 EP - 394 ER - TY - THES A1 - Auer, Daniela T1 - Impact of the chlamydial deubiquitinase ChlaDUB1 on host cell defense T1 - Einfluss der chlamydiellen Deubiquitinase ChlaDUB1 auf die Wirtszellabwehr N2 - The human pathogen Chlamydia trachomatis is the main cause of sexually transmitted infections worldwide. The obligate intracellular bacteria are the causative agent of several diseases that reach from conjunctivitis causing trachoma and blindness as well as salpingitis and urethritis which can lead to infertility if left untreated. In order to gain genetically engineered Chlamydia that inducible knock down specific gene expression, the CRISPRi system was established in C. trachomatis. In a proof of principle experiment it was shown that C. trachomatis pCRISPRi:gCdu1III target ChlaDUB1 expression and reduce the protein amount up to 50 %. Knock-down of the DUB did not influence protein levels of anti-apoptotic Mcl-1 and did not make cells susceptible for apoptosis. However, reduced dCas9 protein size, bacterial growth impairment and off target effects interfering with the GFP signal, form obstacles in CRISPRi system in Chlamydia. For routinely use of the CRISPRi method in C. trachomatis further investigation is needed. Since the bacterial life cycle includes two morphological and functional distinct forms, it is essential for chlamydial spread to complete the development cycle and form infectious progeny. Therefore, Chlamydia has evolved strategies to evade the host immune system in order to stay undetected throughout the developmental cycle. The bacteria prevent host cell apoptosis via stabilization of anti-apoptotic proteins like Mcl-1, Survivin and HIF-1α and activate pro-survival pathways, inhibiting invasion of immune cells to the site of infection. The host cell itself can destroy intruders via cell specific defense systems that involve autophagy and recruitment of professional immune cells. In this thesis the role of the chlamydial deubiuqitinase ChlaDUB1 upon immune evasion was elucidated. With the mutant strain Ctr Tn-cdu1 that encodes for a truncated DUB due to transposon insertion, it was possible to identify ChlaDUB1 as a potent opponent of the autophagic system. Mutant inclusions were targeted by K48 and K63 chain ubiquitination. Subsequently the inclusion was recognized by autophagic receptors like p62, NBR1 and NDP52 that was reversed again by complementation with the active DUB. Xenophagy was promoted so far as LC3 positive phagosomes formed around the inclusion of Ctr Tn-cdu1, which did not fuse with the lysosome. The detected growth defect in human primary cells of Chlamydia missing the active DUB was not traced back to autophagy, but was due to impaired development and replication. It was possible to identify Ankib1, the E3 ligase, that ubiquitinates the chlamydial inclusion in a siRNA based screen. The activating enzyme Ube1 and the conjugating enzyme Ube2L3 are also essential in this process. Chlamydia have a reduced genome and depend on lipids and nutrients that are translocated from the host cell to the inclusion to proliferate. Recruitment of fragmented Golgi stacks to the inclusion surface was prevented when ChlaDUB1 was inactive, probably causing diminished bacterial growth. Additionally, the modification of the inclusion by Ankib1 and subsequent decoration by autophagic markers was not only present in human but also murine cells. Comparison of other Chlamydia strains and species revealed Ankib1 to be located at the proximity of the inclusion in C. trachomatis strains only but not in C. muridarum or C. pneumoniae, indicating that Ankib1 is specifically the E3 ligase of C. trachomatis. Moreover, the role of ChlaDUB1 in infected tissue was of interest, since ChlaDUB1 protein was also found in early EB stage and so might get in contact with invading immune cells after cell lysis. While bacteria spread and infect new host cells, Chlamydia can also infect immune cells. Infection of human neutrophils with Ctr Tn-cdu1 shows less bacterial survival and affirms the importance of the DUB for bacterial fitness in these cells. N2 - Chlamydia trachomatis ist weltweit der häufigste Auslöser von sexuell übertragenen Krankheiten. Das obligat intrazelluläre Bakterium manifestiert sich in diversen Krankheitsbildern, darunter Konjunktivitis, die zu einem Trachom oder sogar Erblindung führen kann und Salpingitis oder Urethritis, die unbehandelt unfruchtbar macht. Das CRISPRi System wurde in C. trachomatis etabliert, um genetisch veränderte Bakterien zu bekommen, in denen induzierbar die spezifische Genexpression herunter gefahren werden kann. Es wurde gezeigt, dass in C. trachomatis pCRISPRi:gCdu1III, einem Stamm, der mit der Genexpression von ChlaDUB1 interferiert, die Menge an ChlaDUB1 um bis zu 50 % reduziert ist. Die Sensitivität für Apoptose durch sinkende Mcl-1 Proteinmengen wurde dadurch jedoch nicht wieder hergestellt. Das verkürzte dCas9 Protein, vermindertes bakterielles Wachstum, sowie Effekte auf andere Genexpressionen, wie z.B. das GFP Signal zeigen die Problematik des CRISPRi Systems in C. trachomatis. Um CRISPRi als Routinemethode für genetische Transformation in Chlamydien zu etablieren, stehen noch weitere Untersuchungen an. Der Lebenszyklus von Chlamydien zeichnet sich durch zwei morphologisch und funktionell unterschiedliche Stadien aus, weshalb die Vollendung des Lebenszyklus und die Produktion infektiöser Partikel essenziell sind. Daher haben die Pathogene Strategien entwickelt, um dem Immunsystem des Wirts zu entgehen und sich unerkannt in der Zelle zu entwickeln. Die Bakterien verhindern Apoptose infizierter Zellen durch die Stabilisierung von anti-apoptotischen Proteinen wie Mcl-1, Survivin und HIF-1α und aktivieren Überlebens-Signalwege, die die Invasion von Immunzellen in das infizierte Gewebe unterdrücken. Die Wirtszelle selbst ist in der Lage bakterielle Eindringlinge durch die eigenen Abwehrmechanismen wie Autophagie und die Rekrutierung von professionellen Immunzellen zu zerstören. In dieser Arbeit wurde die Rolle der chlamydiellen Deubiquitinase ChlaDUB1 auf die Vermeidungsstrategien vor dem Immunsystem untersucht. Mit Hilfe der Mutante Ctr Tn-cdu1, die durch Insertion eines Transposons für eine verkürzte und inaktive Deubiquitinase codiert, konnte gezeigt werden, dass ChlaDUB1 ein Gegenspieler des Autophagiesystems ist. Die Inklusionen der Mutante wurden mit K48 und K63 Ubiquitinketten modifiziert, was die Rekrutierung von Autophagiemarkern wie p62, NBR1 und NDP52 zur Folge hatte. Die Rekomplementierung mit aktivem ChlaDUB1 Protein hob die Modifikation der Inklusion wieder auf. Jedoch wurde die Xenophagie so weit vorangetrieben, bis sich LC3 positive Phagosomen um die Inklusionen von Ctr Tn-cdu1 bildeten, die allerdings nicht mit dem Lysosom verschmolzen. Das beobachtete Wachstumsdefizit in Chlamydien, die keine funktionelle Deubiquitinase exprimieren, konnte nicht auf die Autophagie zurückgeführt werden, sondern war voraussichtlich aufgrund verlangsamter Entwicklung und Replikation entstanden. In einem siRNA basierten Experiment konnte die E3 Ligase Ankib1 für die Ubiquitinierung der Ctr Tn-cdu1 Inklusion identifiziert werden. Des Weiteren sind das Ubiquitin aktivierende Enzym Ube1 und das Ubiquitin konjugierende Enzym Ube2L3 essentiell für die Modifikation der Inklusion. Da Chlamydien ein reduziertes Genom haben und nicht für alle Enzyme selbst kodieren, sind sie auf Lipide und Metabolite der Wirtszelle für ihr Wachstum angewiesen. Die Rekrutierung der fragmentierten Glogi-Membranen zur Inklusionsoberfläche wurde durch inaktives ChlaDUB1 Protein verhindert, das wahrscheinlich die bakterielle Entwicklung negativ beeinflusst. Des Weiteren ubiquitinierte Ankib1 nicht nur Inklusionen in humanen, sondern auch in murinen Zellen, was auch hier die Bindung von Autophagiemarkern zur Folge hatte. Der Vergleich unter verschiedenen chlamydiellen Serotypen und Arten zeigte, dass Ankib1 nur an Inklusionen von C. trachomatis zu finden war, nicht aber für C. muridarum oder C. pneumoniae. Des Weitern wurde die Rolle von ChlaDUB1 in infiziertem Gewebe genauer betrachtet, da die Protease auch während frühen EB Phasen nachgewiesen wurde, in denen sie Kontakt zu immigrierenden Immunzellen haben könnte. Während der Zelllyse werden Bakterien frei gesetzt, die neue Wirtszellen, aber auch Immunzellen, infizieren können. Die Infektion von humanen Neutrophilen mit Ctr Tn-cdu1 zeigte vermindertes bakterielles Wachstum und verdeutlicht die Bedeutung von ChlaDUB1 für das Überleben in diesen Immunzellen. KW - Chlamydia KW - Golgi KW - ChlaDUB1 KW - Cdu1 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178462 ER - TY - JOUR A1 - Feldbauer, Katrin A1 - Schlegel, Jan A1 - Weissbecker, Juliane A1 - Sauer, Frank A1 - Wood, Phillip G. A1 - Bamberg, Ernst A1 - Terpitz, Ulrich T1 - Optochemokine Tandem for Light-Control of Intracellular Ca\(^{2+}\) JF - PLoS ONE N2 - An optochemokine tandem was developed to control the release of calcium from endosomes into the cytosol by light and to analyze the internalization kinetics of G-protein coupled receptors (GPCRs) by electrophysiology. A previously constructed rhodopsin tandem was re-engineered to combine the light-gated Ca\(^{2+}\)-permeable cation channel Channelrhodopsin-2(L132C), CatCh, with the chemokine receptor CXCR4 in a functional tandem protein tCXCR4/CatCh. The GPCR was used as a shuttle protein to displace CatCh from the plasma membrane into intracellular areas. As shown by patch-clamp measurements and confocal laser scanning microscopy, heterologously expressed tCXCR4/CatCh was internalized via the endocytic SDF1/CXCR4 signaling pathway. The kinetics of internalization could be followed electrophysiologically via the amplitude of the CatCh signal. The light-induced release of Ca\(^{2+}\) by tandem endosomes into the cytosol via CatCh was visualized using the Ca\(^{2+}\)-sensitive dyes rhod2 and rhod2-AM showing an increase of intracellular Ca\(^{2+}\) in response to light. KW - capacitance KW - endosomes KW - cell membranes KW - membrane proteins KW - intracellular membranes KW - vesicles KW - confocal laser microscopy KW - cytosol Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178921 VL - 11 IS - 10 ER - TY - THES A1 - Claßen, Alexandra T1 - The ERK-cascade in the pathophysiology of cardiac hypertrophy T1 - Die ERK-Kaskade in der Pathophysiologie der Herzhypertrophie N2 - ERK1/2 are known key players in the pathophysiology of heart failure, but the members of the ERK cascade, in particular Raf1, can also protect the heart from cell death and ischemic injury. An additional autophosphorylation (ERK1 at Thr208, ERK2 at Thr188) empowers ERK1/2 translocation to the nucleus and phosphorylation of nuclear targets which take part in the development of cardiac hypertrophy. Thereby, targeting this additional phosphorylation is a promising pharmacological approach. In this thesis, an in silico model of ERK cascade in the cardiomyocyte is introduced. The model is a semi-quantitive model and its behavior was tested with different softwares (SQUAD and CellNetAnalyzer). Different phosphorylation states of ERK1/2 as well as different stimuli can be reproduced. The different types of stimuli include hypertrophic as well as non-hypertrophic stimuli. With the introduced in-silico model time courses and synergistic as well as antagonistic receptor stimuli combinations can be predicted. The simulated time courses were experimentally validated. SQUAD was mainly used to make predictions about time courses and thresholds, whereas CNA was used to analyze steady states and feedback loops. Furthermore, new targets of ERK1/2 which partially contribute, also in the formation of cardiac hypertrophy, were identified and the most promising of them were illuminated. Important further targets are Caspase 8, GAB2, Mxi-2, SMAD2, FHL2 and SPIN90. Cardiomyocyte gene expression data sets were analyzed to verify involved components and to find further significantly altered genes after induced hypertrophy with TAC (transverse aortic constriction). Changes in the ultrastructure of the cardiomyocyte are the final result of induced hypertrophy. N2 - ERK1/2 sind bekannte Schlüsselfiguren bei der Entstehung der Herzinsuffizienz. Weitere Komponenten der ERK-Kaskade, insbesondere Raf1, können das Herz jedoch vor Zelltod und ischämischem Schaden schützen. Eine zusätzliche Autophosphorylierung von ERK1 an Thr208 bzw. von ERK2 an Thr188 ermöglicht ERK1/2 die Translokation zum Zellkern und befähigt ERK dort zur Phosphorylierung von nukleosolischen Zielproteinen, welche eine Herzmuskelhypertrophie auslösen. Daher erscheint diese zusätzliche Autophosphorylierung als eine vielversprechende pharmakologische Zielstruktur. In dieser Arbeit wird ein in-silico Modell der ERK-Kaskade im Kardiomyozyten präsentiert. Das Modell ist ein semi-quantitatives Modell und wurde mit den Programmen SQUAD und CellNetAnalyzer getestet. Verschiedene Phosphorylierungs-Zustände von ERK1/2 als auch verschiedene Stimuli (hypertrophe als auch nicht-hypertrophe) können mit dem Modell reproduziert werden. Mit dem präsentierten in-silico Modell können sowohl zeitliche Abläufe als auch synergistische und antagonistische Effekte vorhergesagt werden. Die simulierten zeitlichen Abläufe wurden durch in-vitro Experimente validiert. SQUAD wurde hauptsächlich für die Modellierung von zeitlichen Abläufen und Schwellenwerte genutzt, wohingegen CellNetAnalyzer vor allen Dingen zur Analyse von Fließgleichgewichten und Rückkopplungs-Mechanismen genutzt wurde. Darüberhinaus wurden Zielstrukturen von ERK1/2, welche zusätzlich an der Entstehung der Herzhypertrophie mitwirken, identifiziert. Diese umfassen unter anderem Caspase 8, GAB2, Mxi-2, SMAD2, FHL2 und SPIN90. Gen-Expressions-Datensätze von Kardiomyozyten nach TAC (transverse aortic constriction) wurden analysiert. Diese wurden mit den im Model vorhandenen Strukturen verglichen und signifikant veränderte Expressionslevel wurden identifiziert. Veränderungen der Ultrastruktur des Kardiomyozyten sind das Ergebnis der induzierten Hypertrophie. KW - Herzhypertrophie KW - Systembiologie KW - ERK-cascade KW - ERK-Kaskade KW - cardiac hypertrophy KW - in-silico model KW - In-silico Modell Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229664 ER - TY - JOUR A1 - Chen, Jiangtian A1 - Reiher, Wencke A1 - Hermann-Luibl, Christiane A1 - Sellami, Azza A1 - Cognigni, Paola A1 - Kondo, Shu A1 - Helfrich-Förster, Charlotte A1 - Veenstra, Jan A. A1 - Wegener, Christian T1 - Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF JF - PLoS Genetics N2 - Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF. KW - neurons KW - neuroimaging KW - circadian rhythms KW - food consumption KW - sleep KW - biological locomotion KW - Drosophila melanogaster KW - signal peptides Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178170 VL - 12 IS - 9 ER - TY - JOUR A1 - Senthilan, Pingkalai R. A1 - Helfrich-Förster, Charlotte T1 - Rhodopsin 7-The unusual Rhodopsin in Drosophila JF - PeerJ N2 - Rhodopsins are the major photopigments in the fruit fly Drosophila melanogaster. Drosophila express six well-characterized Rhodopsins (Rh1–Rh6) with distinct absorption maxima and expression pattern. In 2000, when the Drosophila genome was published, a novel Rhodopsin gene was discovered: Rhodopsin 7 (Rh7). Rh7 is highly conserved among the Drosophila genus and is also found in other arthropods. Phylogenetic trees based on protein sequences suggest that the seven Drosophila Rhodopsins cluster in three different groups. While Rh1, Rh2 and Rh6 form a “vertebrate-melanopsin-type”–cluster, and Rh3, Rh4 and Rh5 form an “insect-type”-Rhodopsin cluster, Rh7 seem to form its own cluster. Although Rh7 has nearly all important features of a functional Rhodopsin, it differs from other Rhodopsins in its genomic and structural properties, suggesting it might have an overall different role than other known Rhodopsins. KW - vision KW - Drosophila KW - Opsins KW - Rhodopsins KW - phototransduction Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177998 VL - 4 ER - TY - JOUR A1 - Djuzenova, Cholpon S. A1 - Fiedler, Vanessa A1 - Katzer, Astrid A1 - Michel, Konstanze A1 - Deckert, Stefanie A1 - Zimmermann, Heiko A1 - Sukhorukov, Vladimir L. A1 - Flentje, Michael T1 - Dual PI3K-and mTOR-inhibitor PI-103 can either enhance or reduce the radiosensitizing effect of the Hsp90 inhibitor NVP-AUY922 in tumor cells: The role of drug-irradiation schedule JF - Oncotarget N2 - Inhibition of Hsp90 can increase the radiosensitivity of tumor cells. However, inhibition of Hsp90 alone induces the anti-apoptotic Hsp70 and thereby decreases radiosensitivity. Therefore, preventing Hsp70 induction can be a promising strategy for radiosensitization. PI-103, an inhibitor of PI3K and mTOR, has previously been shown to suppress the up-regulation of Hsp70. Here, we explore the impact of combining PI-103 with the Hsp90 inhibitor NVP-AUY922 in irradiated glioblastoma and colon carcinoma cells. We analyzed the cellular response to drug-irradiation treatments by colony-forming assay, expression of several marker proteins, cell cycle progression and induction/repair of DNA damage. Although PI-103, given 24 h prior to irradiation, slightly suppressed the NVP-AUY922-mediated up-regulation of Hsp70, it did not cause radiosensitization and even diminished the radiosensitizing effect of NVP-AUY922. This result can be explained by the activation of PI3K and ERK pathways along with G1-arrest at the time of irradiation. In sharp contrast, PI-103 not only exerted a radiosensitizing effect but also strongly enhanced the radiosensitization by NVP-AUY922 when both inhibitors were added 3 h before irradiation and kept in culture for 24 h. Possible reasons for the observed radiosensitization under this drug-irradiation schedule may be a down-regulation of PI3K and ERK pathways during or directly after irradiation, increased residual DNA damage and strong G2/M arrest 24 h thereafter. We conclude that duration of drug treatment before irradiation plays a key role in the concomitant targeting of PI3K/mTOR and Hsp90 in tumor cells. KW - cell cycle arrest KW - radiation sensitivity KW - histone γH2AX KW - DNA damage KW - colony survival Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177770 VL - 7 IS - 25 ER - TY - JOUR A1 - Endres, Marcel A1 - Kneitz, Susanne A1 - Orth, Martin F. A1 - Perera, Ruwan K. A1 - Zernecke, Alma A1 - Butt, Elke T1 - Regulation of matrix metalloproteinases (MMPs) expression and secretion in MDA-MB-231 breast cancer cells by LIM and SH3 protein 1 (LASP1) JF - Oncotarget N2 - The process of tumor invasion requires degradation of extracellular matrix by proteolytic enzymes. Cancer cells form protrusive invadopodia, which produce and release matrix metalloproteinases (MMPs) to degrade the basement membrane thereby enabling metastasis. We investigated the effect of LASP1, a newly identified protein in invadopodia, on expression, secretion and activation of MMPs in invasive breast tumor cell lines. By analyzing microarray data of in-house generated control and LASP1-depleted MDA-MB-231 breast cancer cells, we observed downregulation of MMP1, -3 and -9 upon LASP1 depletion. This was confirmed by Western blot analysis. Conversely, rescue experiments restored in part MMP expression and secretion. The regulatory effect of LASP1 on MMP expression was also observed in BT-20 breast cancer cells as well as in prostate and bladder cancer cell lines. In line with bioinformatic FunRich analysis of our data, which mapped a high regulation of transcription factors by LASP1, public microarray data analysis detected a correlation between high LASP1 expression and enhanced c-Fos levels, a protein that is part of the transcription factor AP-1 and known to regulate MMP expression. Compatibly, in luciferase reporter assays, AP-1 showed a decreased transcriptional activity after LASP1 knockdown. Zymography assays and Western blot analysis revealed an additional promotion of MMP secretion into the extracellular matrix by LASP1, thus, most likely, altering the microenvironment during cancer progression. The newly identified role of LASP1 in regulating matrix degradation by affecting MMP transcription and secretion elucidated the migratory potential of LASP1 overexpressing aggressive tumor cells in earlier studies. KW - LASP1 KW - c-Fos KW - extracellular matrix KW - AP-1 KW - matrix metalloproteinases KW - breast cancer Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176920 VL - 7 IS - 39 ER - TY - JOUR A1 - Lehenberger, Maximilian A1 - Benkert, Markus A1 - Biedermann, Peter H. W. T1 - Ethanol-Enriched Substrate Facilitates Ambrosia Beetle Fungi, but Inhibits Their Pathogens and Fungal Symbionts of Bark Beetles JF - Frontiers in Microbiology N2 - Bark beetles (sensu lato) colonize woody tissues like phloem or xylem and are associated with a broad range of micro-organisms. Specific fungi in the ascomycete orders Hypocreales, Microascales and Ophistomatales as well as the basidiomycete Russulales have been found to be of high importance for successful tree colonization and reproduction in many species. While fungal mutualisms are facultative for most phloem-colonizing bark beetles (sensu stricto), xylem-colonizing ambrosia beetles are long known to obligatorily depend on mutualistic fungi for nutrition of adults and larvae. Recently, a defensive role of fungal mutualists for their ambrosia beetle hosts was revealed: Few tested mutualists outcompeted other beetle-antagonistic fungi by their ability to produce, detoxify and metabolize ethanol, which is naturally occurring in stressed and/or dying trees that many ambrosia beetle species preferentially colonize. Here, we aim to test (i) how widespread beneficial effects of ethanol are among the independently evolved lineages of ambrosia beetle fungal mutualists and (ii) whether it is also present in common fungal symbionts of two bark beetle species (Ips typographus, Dendroctonus ponderosae) and some general fungal antagonists of bark and ambrosia beetle species. The majority of mutualistic ambrosia beetle fungi tested benefited (or at least were not harmed) by the presence of ethanol in terms of growth parameters (e.g., biomass), whereas fungal antagonists were inhibited. This confirms the competitive advantage of nutritional mutualists in the beetle’s preferred, ethanol-containing host material. Even though most bark beetle fungi are found in the same phylogenetic lineages and ancestral to the ambrosia beetle (sensu stricto) fungi, most of them were highly negatively affected by ethanol and only a nutritional mutualist of Dendroctonus ponderosae benefited, however. This suggests that ethanol tolerance is a derived trait in nutritional fungal mutualists, particularly in ambrosia beetles that show cooperative farming of their fungi. KW - ambrosia fungi KW - bark and ambrosia beetles KW - symbiont selection KW - ethanol KW - detoxification KW - Ips typographus Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222222 SN - 1664-302X VL - 11 ER - TY - JOUR A1 - Adolfi, Mateus C. A1 - Herpin, Amaury A1 - Martinez-Bengochea, Anabel A1 - Kneitz, Susanne A1 - Regensburger, Martina A1 - Grunwald, David J. A1 - Schartl, Manfred T1 - Crosstalk Between Retinoic Acid and Sex-Related Genes Controls Germ Cell Fate and Gametogenesis in Medaka JF - Frontiers in Cell and Developmental Biology N2 - Sex determination (SD) is a highly diverse and complex mechanism. In vertebrates, one of the first morphological differences between the sexes is the timing of initiation of the first meiosis, where its initiation occurs first in female and later in male. Thus, SD is intimately related to the responsiveness of the germ cells to undergo meiosis in a sex-specific manner. In some vertebrates, it has been reported that the timing for meiosis entry would be under control of retinoic acid (RA), through activation of Stra8. In this study, we used a fish model species for sex determination and lacking the stra8 gene, the Japanese medaka (Oryzias latipes), to investigate the connection between RA and the sex determination pathway. Exogenous RA treatments act as a stress factor inhibiting germ cell differentiation probably by activation of dmrt1a and amh. Disruption of the RA degrading enzyme gene cyp26a1 induced precocious meiosis and oogenesis in embryos/hatchlings of female and even some males. Transcriptome analyzes of cyp26a1–/–adult gonads revealed upregulation of genes related to germ cell differentiation and meiosis, in both ovaries and testes. Our findings show that germ cells respond to RA in a stra8 independent model species. The responsiveness to RA is conferred by sex-related genes, restricting its action to the sex differentiation period in both sexes. KW - sex determination KW - retinoic acid KW - meiosis KW - gametogenesis KW - medaka Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222669 SN - 2296-634X VL - 8 ER - TY - JOUR A1 - Kessie, David K. A1 - Lodes, Nina A1 - Oberwinkler, Heike A1 - Goldman, William E. A1 - Walles, Thorsten A1 - Steinke, Maria A1 - Gross, Roy T1 - Activity of Tracheal Cytotoxin of Bordetella pertussis in a Human Tracheobronchial 3D Tissue Model JF - Frontiers in Cellular and Infection Microbiology N2 - Bordetella pertussis is a highly contagious pathogen which causes whooping cough in humans. A major pathophysiology of infection is the extrusion of ciliated cells and subsequent disruption of the respiratory mucosa. Tracheal cytotoxin (TCT) is the only virulence factor produced by B. pertussis that has been able to recapitulate this pathology in animal models. This pathophysiology is well characterized in a hamster tracheal model, but human data are lacking due to scarcity of donor material. We assessed the impact of TCT and lipopolysaccharide (LPS) on the functional integrity of the human airway mucosa by using in vitro airway mucosa models developed by co-culturing human tracheobronchial epithelial cells and human tracheobronchial fibroblasts on porcine small intestinal submucosa scaffold under airlift conditions. TCT and LPS either alone and in combination induced blebbing and necrosis of the ciliated epithelia. TCT and LPS induced loss of ciliated epithelial cells and hyper-mucus production which interfered with mucociliary clearance. In addition, the toxins had a disruptive effect on the tight junction organization, significantly reduced transepithelial electrical resistance and increased FITC-Dextran permeability after toxin incubation. In summary, the results indicate that TCT collaborates with LPS to induce the disruption of the human airway mucosa as reported for the hamster tracheal model. KW - tracheal cytotoxin KW - airway epithelia KW - tissue model KW - ciliostasis KW - tight junction KW - Bordetella pertussis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222736 SN - 2235-2988 VL - 10 ER - TY - JOUR A1 - Beer, Katharina A1 - Helfrich-Förster, Charlotte T1 - Model and Non-model Insects in Chronobiology JF - Frontiers in Behavioral Neuroscience N2 - The fruit fly Drosophila melanogaster is an established model organism in chronobiology, because genetic manipulation and breeding in the laboratory are easy. The circadian clock neuroanatomy in D. melanogaster is one of the best-known clock networks in insects and basic circadian behavior has been characterized in detail in this insect. Another model in chronobiology is the honey bee Apis mellifera, of which diurnal foraging behavior has been described already in the early twentieth century. A. mellifera hallmarks the research on the interplay between the clock and sociality and complex behaviors like sun compass navigation and time-place-learning. Nevertheless, there are aspects of clock structure and function, like for example the role of the clock in photoperiodism and diapause, which can be only insufficiently investigated in these two models. Unlike high-latitude flies such as Chymomyza costata or D. ezoana, cosmopolitan D. melanogaster flies do not display a photoperiodic diapause. Similarly, A. mellifera bees do not go into “real” diapause, but most solitary bee species exhibit an obligatory diapause. Furthermore, sociality evolved in different Hymenoptera independently, wherefore it might be misleading to study the social clock only in one social insect. Consequently, additional research on non-model insects is required to understand the circadian clock in Diptera and Hymenoptera. In this review, we introduce the two chronobiology model insects D. melanogaster and A. mellifera, compare them with other insects and show their advantages and limitations as general models for insect circadian clocks. KW - circadian clock KW - complex behavior KW - diapause KW - sociality KW - Drosophila melanogaster KW - Apis mellifera Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218721 SN - 1662-5153 VL - 14 ER - TY - RPRT A1 - Dandekar, Thomas T1 - A new cosmology of a crystallization process (decoherence) from the surrounding quantum soup provides heuristics to unify general relativity and quantum physics by solid state physics T1 - Eine neue Kosmologie eines Kristallisationsprozesses (Dekohärenz) vom umgebenden Quantenschaum bietet Heuristiken, um allgemeine Relativitätstheorie und Quantenphysik durch Festkörperphysik zu vereinen N2 - We explore a cosmology where the Big Bang singularity is replaced by a condensation event of interacting strings. We study the transition from an uncontrolled, chaotic soup (“before”) to a clearly interacting “real world”. Cosmological inflation scenarios do not fit current observations and are avoided. Instead, long-range interactions inside this crystallization event limit growth and crystal symmetries ensure the same laws of nature and basic symmetries over our domain. Tiny mis-arrangements present nuclei of superclusters and galaxies and crystal structure leads to the arrangement of dark (halo regions) and normal matter (galaxy nuclei) so convenient for galaxy formation. Crystals come and go, allowing an evolutionary cosmology where entropic forces from the quantum soup “outside” of the crystal try to dissolve it. These would correspond to dark energy and leads to a big rip scenario in 70 Gy. Preference of crystals with optimal growth and most condensation nuclei for the next generation of crystals may select for multiple self-organizing processes within the crystal, explaining “fine-tuning” of the local “laws of nature” (the symmetry relations formed within the crystal, its “unit cell”) to be particular favorable for self-organizing processes including life or even conscious observers in our universe. Independent of cosmology, a crystallization event may explain quantum-decoherence in general: The fact, that in our macroscopic everyday world we only see one reality. This contrasts strongly with the quantum world where you have coherence, a superposition of all quantum states. We suggest that a “real world” (so our everyday macroscopic world) happens only in our domain, i.e. inside a crystal. “Outside” of our domain and our observable universe there is the quantum soup of boiling quantum foam and superposition of all possibilities. In our crystallized world the vacuum no longer boils but is cooled down by the crystallization event and hence is 10**20 smaller, exactly as observed in our everyday world. As we live in a “solid” state, within a crystal, the different quanta which build our world have all their different states nicely separated. This theory postulates there are only n quanta and m states available for them (there is no Everett-like ever splitting multiverse after each decision). In the solid state we live in, there is decoherence, the states are nicely separated. The arrow of entropy for each edge of the crystal forms one fate, one worldline or clear development of a world, while the layers of the crystal are different system states. Some mathematical leads from loop quantum gravity point to required interactions and potentials. A complete mathematical treatment of this unified theory is far too demanding currently. Interaction potentials for strings or membranes of any dimension allow a solid state of quanta, so allowing decoherence in our observed world are challenging to calculate. However, if we introduce here the heuristic that any type of physical interaction of strings corresponds just to a type of calculation, there is already since 1898 the Hurwitz theorem showing that then only 1D, 2D, 4D and 8D (octonions) allow complex or hypercomplex number calculations. No other hypercomplex numbers and hence dimensions or symmetries are possible to allow calculations without yielding divisions by zero. However, the richest solution allowed by the Hurwitz theorem, octonions, is actually the observed symmetry of our universe, E8.   KW - Kosmologie KW - cosmology KW - Hurwitz-Theorem KW - Quantenschleifen-Gravitation KW - Verschränkung KW - Qubits KW - Hurwitz-Theorem KW - loop quantum gravity KW - entanglement KW - Qubits Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230769 ER - TY - JOUR A1 - Beer, Katharina A1 - Helfrich-Förster, Charlotte T1 - Post-embryonic Development of the Circadian Clock Seems to Correlate With Social Life Style in Bees JF - Frontiers in Cell and Developmental Biology N2 - Social life style can influence many aspects of an animal’s daily life, but it has not yet been clarified, whether development of the circadian clock in social and solitary living bees differs. In a comparative study, with the social honey bee, Apis mellifera, and the solitary mason bee, Osmia bicornis, we now found indications for a differentially timed clock development in social and solitary bees. Newly emerged solitary bees showed rhythmic locomotion right away and the number of neurons in the brain that produce the clock component pigment-dispersing factor (PDF) did not change during aging of the adult solitary bee. Honey bees on the other hand, showed no circadian locomotion directly after emergence and the neuronal clock network continued to grow after emergence. Social bees appear to emerge at an early developmental stage at which the circadian clock is still immature, but bees are already able to fulfill in-hive tasks. KW - social KW - honey bee KW - solitary bee KW - circadian clock KW - activity rhythm KW - neuronal network KW - development Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216450 SN - 2296-634X VL - 8 ER - TY - JOUR A1 - Prieto‐Garcia, Cristian A1 - Hartmann, Oliver A1 - Reissland, Michaela A1 - Braun, Fabian A1 - Fischer, Thomas A1 - Walz, Susanne A1 - Schülein‐Völk, Christina A1 - Eilers, Ursula A1 - Ade, Carsten P. A1 - Calzado, Marco A. A1 - Orian, Amir A1 - Maric, Hans M. A1 - Münch, Christian A1 - Rosenfeldt, Mathias A1 - Eilers, Martin A1 - Diefenbacher, Markus E. T1 - Maintaining protein stability of ∆Np63 via USP28 is required by squamous cancer cells JF - EMBO Molecular Medicine N2 - The transcription factor ∆Np63 is a master regulator of epithelial cell identity and essential for the survival of squamous cell carcinoma (SCC) of lung, head and neck, oesophagus, cervix and skin. Here, we report that the deubiquitylase USP28 stabilizes ∆Np63 and maintains elevated ∆NP63 levels in SCC by counteracting its proteasome‐mediated degradation. Impaired USP28 activity, either genetically or pharmacologically, abrogates the transcriptional identity and suppresses growth and survival of human SCC cells. CRISPR/Cas9‐engineered in vivo mouse models establish that endogenous USP28 is strictly required for both induction and maintenance of lung SCC. Our data strongly suggest that targeting ∆Np63 abundance via inhibition of USP28 is a promising strategy for the treatment of SCC tumours. KW - ∆Np63 KW - NOTCH KW - squamous cell carcinoma KW - 28 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218303 VL - 12 IS - 4 ER - TY - JOUR A1 - Seitz, Nicola A1 - vanEngelsdorp, Dennis A1 - Leonhardt, Sara D. T1 - Are native and non‐native pollinator friendly plants equally valuable for native wild bee communities? JF - Ecology and Evolution N2 - Bees rely on floral pollen and nectar for food. Therefore, pollinator friendly plantings are often used to enrich habitats in bee conservation efforts. As part of these plantings, non‐native plants may provide valuable floral resources, but their effects on native bee communities have not been assessed in direct comparison with native pollinator friendly plantings. In this study, we performed a common garden experiment by seeding mixes of 20 native and 20 non‐native pollinator friendly plant species at separate neighboring plots at three sites in Maryland, USA, and recorded flower visitors for 2 years. A total of 3,744 bees (120 species) were collected. Bee abundance and species richness were either similar across plant types (midseason and for abundance also late season) or lower at native than at non‐native plots (early season and for richness also late season). The overall bee community composition differed significantly between native and non‐native plots, with 11 and 23 bee species being found exclusively at one plot type or the other, respectively. Additionally, some species were more abundant at native plant plots, while others were more abundant at non‐natives. Native plants hosted more specialized plant–bee visitation networks than non‐native plants. Three species out of the five most abundant bee species were more specialized when foraging on native plants than on non‐native plants. Overall, visitation networks were more specialized in the early season than in late seasons. Our findings suggest that non‐native plants can benefit native pollinators, but may alter foraging patterns, bee community assemblage, and bee–plant network structures. KW - bee conservation KW - common garden experiment KW - exotic plants KW - non‐native plants KW - plant–bee visitation networks KW - pollinator friendly plants KW - wild bees Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218439 VL - 10 IS - 23 ER - TY - JOUR A1 - Rösing, Nils A1 - Salvador, Ellaine A1 - Güntzel, Paul A1 - Kempe, Christoph A1 - Burek, Malgorzata A1 - Holzgrabe, Ulrike A1 - Soukhoroukov, Vladimir A1 - Wunder, Christian A1 - Förster, Carola T1 - Neuroprotective Effects of Isosteviol Sodium in Murine Brain Capillary Cerebellar Endothelial Cells (cerebEND) After Hypoxia JF - Frontiers in Cellular Neuroscience N2 - Ischemic stroke is one of the leading causes of death worldwide. It damages neurons and other supporting cellular elements in the brain. However, the impairment is not only confined to the region of assault but the surrounding area as well. Besides, it also brings about damage to the blood-brain barrier (BBB) which in turn leads to microvascular failure and edema. Hence, this necessitates an on-going, continuous search for intervention strategies and effective treatment. Of late, the natural sweetener stevioside proved to exhibit neuroprotective effects and therapeutic benefits against cerebral ischemia-induced injury. Its injectable formulation, isosteviol sodium (STVNA) also demonstrated favorable results. Nonetheless, its effects on the BBB have not yet been investigated to date. As such, this present study was designed to assess the effects of STVNA in our in vitro stroke model of the BBB.The integrity and permeability of the BBB are governed and maintained by tight junction proteins (TJPs) such as claudin-5 and occludin. Our data show increased claudin-5 and occludin expression in oxygen and glucose (OGD)-deprived murine brain capillary cerebellar endothelial cells (cerebEND) after STVNa treatment. Likewise, the upregulation of the transmembrane protein integrin-αv was also observed. Finally, cell volume was reduced with the simultaneous administration of STVNA and OGD in cerebEND cells. In neuropathologies such as stroke, the failure of cell volume control is a major feature leading to loss of cells in the penumbra as well as adverse outcomes. Our initial findings, therefore, point to the neuroprotective effects of STVNA at the BBB in vitro, which warrant further investigation for a possible future clinical intervention. KW - isosteviol sodium KW - hypoxia KW - cerebEND cells KW - blood brain barrier KW - neuroprotection Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215013 SN - 1662-5102 VL - 14 ER - TY - JOUR A1 - Koch, Rebecca-Diana A1 - Hörner, Eva-Maria A1 - Münch, Nadine A1 - Maier, Elke A1 - Kozjak-Pavlovic, Vera T1 - Modulation of Host Cell Death and Lysis Are Required for the Release of Simkania negevensis JF - Frontiers in Cellular and Infection Microbiology N2 - Simkania negevensis is a Chlamydia-like bacterium and emerging pathogen of the respiratory tract. It is an obligate intracellular bacterium with a biphasic developmental cycle, which replicates in a wide range of host cells. The life cycle of S. negevensis has been shown to proceed for more than 12 days, but little is known about the mechanisms that mediate the cellular release of these bacteria. This study focuses on the investigation of host cell exit by S. negevensis and its connection to host cell death modulation. We show that Simkania-infected epithelial HeLa as well as macrophage-like THP-1 cells reduce in number during the course of infection. At the same time, the infectivity of the cell culture supernatant increases, starting at the day 3 for HeLa and day 4 for THP-1 cells and reaching maximum at day 5 post infection. This correlates with the ability of S. negevensis to block TNFα-, but not staurosporin-induced cell death up to 3 days post infection, after which cell death is boosted by the presence of bacteria. Mitochondrial permeabilization through Bax and Bak is not essential for host cell lysis and release of S. negevensis. The inhibition of caspases by Z-VAD-FMK, caspase 1 by Ac-YVAD-CMK, and proteases significantly reduces the number of released infectious particles. In addition, the inhibition of myosin II by blebbistatin also strongly affects Simkania release, pointing to a possible double mechanism of exit through host cell lysis and potentially extrusion. KW - exit KW - release KW - cell death KW - caspases Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215158 SN - 2235-2988 VL - 10 ER - TY - JOUR A1 - Biedermann, Peter H. W. T1 - Cooperative Breeding in the Ambrosia Beetle Xyleborus affinis and Management of Its Fungal Symbionts JF - Frontiers in Ecology and Evolution N2 - Fungus-farming is known from attine ants, macrotermites, and ambrosia beetles (Scolytinae, Platypodinae). Farming ant and termite societies are superorganismal and grow fungal cultivars in monocultures. Social organization of ambrosia beetle groups and their farming systems are poorly studied, because of their enigmatic life within tunnel systems inside of wood. Ambrosia beetle-fungus symbioses evolved many times independently in both the beetles and their fungal cultivars. Observations suggest that there is evolutionary convergence between these lineages, but also a high variation in the degree of sociality and the modes of fungiculture. Using a laboratory observation technique, I here tried to give insights into the social system and fungus symbiosis of the sugar-cane borer, Xyleborus affinis Eichhoff (Scolytinae: Curculionidae), a currently poorly studied ambrosia beetle. The study revealed a cooperatively breeding system characterized by delayed dispersal of adult daughters, alloparental brood care by larvae and adults, and about half of the totipotent adult daughters laying eggs within the natal nest. Most interesting, there was a tendency of egg-laying females to engage more commonly in mutually beneficial behaviors than non-egg-layers. Fungus gardens covering gallery walls composed of five different filamentous fungi. A Raffaelea isolate was predominant and together with an unidentified fungus likely served as the main food for adults and larvae. Three isolates, a Mucor, a Fusarium and a Phaeoacremonium isolate were most abundant in the oldest gallery part close to the entrance; Mucor, Fusarium and the Raffaelea isolate in diseased individuals. Additionally, there was correlative evidence for some fungal isoaltes influencing beetle feeding and hygienic behaviors. Overall, X. affinis is now the second ambrosia beetle that can be classified as a cooperative breeder with division of labor among and between adults and larvae. KW - cooperative breeding KW - bark beetle KW - insect agriculture KW - symbiosis KW - fungus community KW - social behavior KW - fungus-farming KW - mutualism Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215662 SN - 2296-701X VL - 8 ER - TY - JOUR A1 - Vikuk, Veronika A1 - Fuchs, Benjamin A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Rueb, Selina A1 - Krauss, Jochen T1 - Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany? JF - Journal of Fungi N2 - Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable. KW - Epichloë KW - Lolium perenne KW - toxicity KW - grasslands KW - HPLC/UPLC methods KW - endophyte KW - plant fresh/dry weight KW - alkaloid detection methods KW - mycotoxins KW - phenology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213171 SN - 2309-608X VL - 6 IS - 3 ER - TY - JOUR A1 - Weiss, Esther A1 - Schlegel, Jan A1 - Terpitz, Ulrich A1 - Weber, Michael A1 - Linde, Jörg A1 - Schmitt, Anna-Lena A1 - Hünniger, Kerstin A1 - Marischen, Lothar A1 - Gamon, Florian A1 - Bauer, Joachim A1 - Löffler, Claudia A1 - Kurzai, Oliver A1 - Morton, Charles Oliver A1 - Sauer, Markus A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - Reconstituting NK Cells After Allogeneic Stem Cell Transplantation Show Impaired Response to the Fungal Pathogen Aspergillus fumigatus JF - Frontiers in Immunology N2 - Delayed natural killer (NK) cell reconstitution after allogeneic stem cell transplantation (alloSCT) is associated with a higher risk of developing invasive aspergillosis. The interaction of NK cells with the human pathogen Aspergillus (A.) fumigatus is mediated by the fungal recognition receptor CD56, which is relocated to the fungal interface after contact. Blocking of CD56 signaling inhibits the fungal mediated chemokine secretion of MIP-1α, MIP-1β, and RANTES and reduces cell activation, indicating a functional role of CD56 in fungal recognition. We collected peripheral blood from recipients of an allograft at defined time points after alloSCT (day 60, 90, 120, 180). NK cells were isolated, directly challenged with live A. fumigatus germ tubes, and cell function was analyzed and compared to healthy age and gender-matched individuals. After alloSCT, NK cells displayed a higher percentage of CD56\(^{bright}\)CD16\(^{dim}\) cells throughout the time of blood collection. However, CD56 binding and relocalization to the fungal contact side were decreased. We were able to correlate this deficiency to the administration of corticosteroid therapy that further negatively influenced the secretion of MIP-1α, MIP-1β, and RANTES. As a consequence, the treatment of healthy NK cells ex vivo with corticosteroids abrogated chemokine secretion measured by multiplex immunoassay. Furthermore, we analyzed NK cells regarding their actin cytoskeleton by Structured Illumination Microscopy (SIM) and flow cytometry and demonstrate an actin dysfunction of NK cells shown by reduced F-actin content after fungal co-cultivation early after alloSCT. This dysfunction remains until 180 days post-alloSCT, concluding that further actin-dependent cellular processes may be negatively influenced after alloSCT. To investigate the molecular pathomechansism, we compared CD56 receptor mobility on the plasma membrane of healthy and alloSCT primary NK cells by single-molecule tracking. The results were very robust and reproducible between tested conditions which point to a different molecular mechanism and emphasize the importance of proper CD56 mobility. KW - natural killer cell KW - stem cell transplantation KW - corticosteroids KW - CCL3 KW - CCL4 KW - CCL5 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-212581 SN - 1664-3224 VL - 11 ER - TY - JOUR A1 - Ferber, Elena A1 - Gerhards, Julian A1 - Sauer, Miriam A1 - Krischke, Markus A1 - Dittrich, Marcus T. A1 - Müller, Tobias A1 - Berger, Susanne A1 - Fekete, Agnes A1 - Mueller, Martin J. T1 - Chemical Priming by Isothiocyanates Protects Against Intoxication by Products of the Mustard Oil Bomb JF - Frontiers in Plant Science N2 - In Brassicaceae, tissue damage triggers the mustard oil bomb i.e., activates the degradation of glucosinolates by myrosinases leading to a rapid accumulation of isothiocyanates at the site of damage. Isothiocyanates are reactive electrophilic species (RES) known to covalently bind to thiols in proteins and glutathione, a process that is not only toxic to herbivores and microbes but can also cause cell death of healthy plant tissues. Previously, it has been shown that subtoxic isothiocyanate concentrations can induce transcriptional reprogramming in intact plant cells. Glutathione depletion by RES leading to breakdown of the redox potential has been proposed as a central and common RES signal transduction mechanism. Using transcriptome analyses, we show that after exposure of Arabidopsis seedlings (grown in liquid culture) to subtoxic concentrations of sulforaphane hundreds of genes were regulated without depletion of the cellular glutathione pool. Heat shock genes were among the most highly up-regulated genes and this response was found to be dependent on the canonical heat shock factors A1 (HSFA1). HSFA1-deficient plants were more sensitive to isothiocyanates than wild type plants. Moreover, pretreatment of Arabidopsis seedlings with subtoxic concentrations of isothiocyanates increased resistance against exposure to toxic levels of isothiocyanates and, hence, may reduce the autotoxicity of the mustard oil bomb by inducing cell protection mechanisms. KW - autotoxicity KW - heat shock response KW - isothiocyanates KW - mustard oil bomb KW - reactive electrophilic species KW - redox homeostasis KW - sulforaphane Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207104 SN - 1664-462X VL - 11 ER - TY - JOUR A1 - Kunz, Tobias C. A1 - Götz, Ralph A1 - Gao, Shiqiang A1 - Sauer, Markus A1 - Kozjak-Pavlovic, Vera T1 - Using Expansion Microscopy to Visualize and Characterize the Morphology of Mitochondrial Cristae JF - Frontiers in Cell and Developmental Biology N2 - Mitochondria are double membrane bound organelles indispensable for biological processes such as apoptosis, cell signaling, and the production of many important metabolites, which includes ATP that is generated during the process known as oxidative phosphorylation (OXPHOS). The inner membrane contains folds called cristae, which increase the membrane surface and thus the amount of membrane-bound proteins necessary for the OXPHOS. These folds have been of great interest not only because of their importance for energy conversion, but also because changes in morphology have been linked to a broad range of diseases from cancer, diabetes, neurodegenerative diseases, to aging and infection. With a distance between opposing cristae membranes often below 100 nm, conventional fluorescence imaging cannot provide a resolution sufficient for resolving these structures. For this reason, various highly specialized super-resolution methods including dSTORM, PALM, STED, and SIM have been applied for cristae visualization. Expansion Microscopy (ExM) offers the possibility to perform super-resolution microscopy on conventional confocal microscopes by embedding the sample into a swellable hydrogel that is isotropically expanded by a factor of 4–4.5, improving the resolution to 60–70 nm on conventional confocal microscopes, which can be further increased to ∼ 30 nm laterally using SIM. Here, we demonstrate that the expression of the mitochondrial creatine kinase MtCK linked to marker protein GFP (MtCK-GFP), which localizes to the space between the outer and the inner mitochondrial membrane, can be used as a cristae marker. Applying ExM on mitochondria labeled with this construct enables visualization of morphological changes of cristae and localization studies of mitochondrial proteins relative to cristae without the need for specialized setups. For the first time we present the combination of specific mitochondrial intermembrane space labeling and ExM as a tool for studying internal structure of mitochondria. KW - Expansion microscopy KW - mitochondria KW - cristae KW - structured illumination microscope KW - ultrastructure Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208296 SN - 2296-634X VL - 8 ER -