@phdthesis{Lehmann2020, author = {Lehmann, Julian}, title = {Hochaufl{\"o}sende Fluoreszenzmikroskopie beleuchtet den Oligomerisierungsstatus pflanzlicher Membranproteine}, doi = {10.25972/OPUS-21176}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211762}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {SLAC/SLAH Anionenkan{\"a}le, die zur Familie der langsamen Anionenkan{\"a}le geh{\"o}ren, repr{\"a}sentieren Schl{\"u}sselproteine in der pflanzlichen Stressantwort. Neben ihrer Aufgabe in Stresssituationen, ist eine Untergruppe der Kan{\"a}le f{\"u}r die Beladung der Leitgef{\"a}ße mit Nitrat und Chlorid in der Stele der Pflanzenwurzeln verantwortlich. Biophysikalische und pflanzenphysiologische Studien stellten heraus, dass vor Allem der Anionenkanal SLAH3 f{\"u}r die Beladung der Xylem Leitgef{\"a}ße mit Nitrat und Chlorid verantwortlich ist. Ihm zur Seite gestellt werden noch die elektrisch inaktiven Homologe SLAH1 und SLAH4 in der Wurzel exprimiert. Sie steuern die Aktivit{\"a}t von SLAH3 durch die Assemblierung zu SLAH1/SLAH3 oder SLAH3/SLAH4 Heteromeren. Neben der Kontrolle durch Heteromerisierungsereignisse, werden SLAH3 Homomere sehr spezifisch und schnell durch zytosolische Ans{\"a}uerung aktiviert. Obwohl bereits die Kristallstruktur des bakteriellen Homologs HiTehA zu pflanzlichen SLAC/SLAH Anionenkan{\"a}len bekannt ist, welche HiTehA als Trimer charakterisiert, sind die St{\"o}chiometrie und der Polymerisierungsgrad der pflanzlichen SLAC/SLAHs bisher noch unbekannt. Die Fluoreszenzmikroskopie umfasst viele etablierte Anwendungsmethoden, wie die konfokale Laserrastermikroskopie (CLSM), Techniken mit verbesserter Aufl{\"o}sung, wie die Mikroskopie mit strukturierter Beleuchtung (SIM) und hochaufl{\"o}sende Methoden, welche durch die Lokalisationsmikroskopie (z.B. dSTORM und PALM) oder die Expansionsmikroskopie (ExM) vertreten werden. Diese unterschiedlichen Mikroskopie-methoden erm{\"o}glichen neue Einblicke in die Organisation von Proteinen in biologischen Systemen, die bis auf die molekulare Ebene hinunterreichen. Insbesondere im Bereich der hochaufl{\"o}senden Fluoreszenzmikroskopie sind im Gegensatz zu tierischen Frage-stellungen bisher jedoch nur wenige Untersuchungen in pflanzlichen Geweben durchgef{\"u}hrt worden. Die Lokalisationsmikroskopie erm{\"o}glicht die Quantifizierung einzelner Molek{\"u}le in nativen Systemen und l{\"a}sst {\"u}berdies R{\"u}ckschl{\"u}sse auf den Polymerisierungsgrad von Proteinen zu. Da Poly- und Heteromerisierung von Proteinen oftmals mit der Funktionalit{\"a}t eines entsprechenden Proteins einhergeht, wie es bei den SLAC/SLAH Anionenkan{\"a}len der Fall ist, wurden in dieser Arbeit PALM Messungen zur Untersuchung des Polymerisierungsgrades und Interaktionsmuster der Anionenkan{\"a}le angewendet. Ferner wurden Expressionsmuster der SLAC/SLAHs untersucht und zudem Mikroskopieanwendungen im Pflanzengewebe etabliert und verbessert. In Bezug auf die Mikroskopieanwendungen konnten wir in Arabidopsis thaliana (At) Wurzeln die polare Verteilung von PIN Proteinen mittels SIM best{\"a}tigen und die gruppierte Verteilung in der Plasmamembran am Zellpol aufl{\"o}sen. In Wurzel-querschnitten war es m{\"o}glich, Zellw{\"a}nde zu vermessen, den Aufbau der Pflanzenwurzel mit den verschiedenen Zelltypen zu rekonstruieren und diesen in Zusammenhang mit Zellwanddicken zu bringen. Anhand dieser Aufnahmen ließ sich die Aufl{\"o}sungsgrenze eines SIM-Mikroskops bestimmen, weshalb diese Probe als Modellstruktur f{\"u}r Aufl{\"o}sungsanalysen, zur Kontrolle f{\"u}r die korrekte Bildverarbeitung bei hochaufl{\"o}sender Bildgebung und andere Fragestellungen empfohlen werden kann. F{\"u}r die Expansionsmikroskopie in pflanzlichen Proben konnten ein enzym- und ein denaturierungsbasiertes Pr{\"a}parationsprotokoll etabliert werden. Dabei wurden ganze At Setzlinge, Wurzelabschnitte und Blattst{\"u}cke gef{\"a}rbt, expandiert und mit zwei bis drei Mal verbesserter Aufl{\"o}sung bildlich dargestellt. In diesem Zusammenhang waren Aufnahmen ganzer Wurzel- und Blattproben mit beeindruckender Eindringtiefe und extrem geringem Hintergrundsignal m{\"o}glich. Zudem wurden die Daten kritisch betrachtet, Probleme aufgezeigt, gewebespezifische Ver{\"a}nderungen dargestellt und limitierende Faktoren f{\"u}r die ExM in Pflanzenproben thematisiert. Im Fokus dieser Arbeit stand die Untersuchung der SLAC/SLAH Proteine. SLAH2 wird in den Wurzeln vornehmlich in Endodermis- und Perizykelzellen exprimiert, was anhand verschiedener At SLAH2 YFP Mutanten untersucht werden konnte. Dies unterst{\"u}tzt die Annahme, dass SLAH2 bei der Beladung der Leitgef{\"a}ße mit Nitrat maßgeblich beteiligt ist. Es ist denkbar, dass SLAH2 ebenfalls eine wachstumsbeeinflussende Funktion {\"u}ber die Regulation von Nitratkonzentrationen zugeschrieben werden kann. Darauf deuten vor allem die verst{\"a}rkte Expression von SLAH2 im Bereich der Seitenwurzeln und die heterogene Expression in der Elongations-, Differenzierungs- und meristematischen Zone hin. Die Membranst{\"a}ndigkeit von SLAH4 konnte nachgewiesen werden und FRET FLIM Untersuchungen zeigten eine hohe Affinit{\"a}t von SLAH4 zu SLAH3, was die beiden Homologe als Interaktionspartner identifiziert. F{\"u}r die Bestimmung des Oligomerisierungsgrades mittels PALM wurden die pflanzlichen Anionenkan{\"a}le in tierischen COS7-Zellen exprimiert. Die elektrophysiologische Funktionalit{\"a}t der mEOS2-SLAC/SLAH-Konstrukte wurde mit Hilfe von Patch-Clamp-Versuchen in COS7-Zellen {\"u}berpr{\"u}ft. Um Expressionslevel, Membranst{\"a}ndigkeit und die Verteilung {\"u}ber die Membran der SLAC/SLAHs zu verifizieren, wurden dSTORM-Aufnahmen herangezogen Schließlich erm{\"o}glichten PALM-Aufnahmen die Bestimmung des Polymerisierungs-grades der SLAC/SLAH Anionenkan{\"a}le, die st{\"o}chiometrischen Ver{\"a}nderungen bei Heteromerisierung von SLAH3 mit SLAH1 oder SLAH4 und auch der Einfluss einer zytosolischer Ans{\"a}uerung auf den Polymerisierungsgrad von SLAH3 Homomeren. Zudem weisen die Oligomerisierungsanalysen von SLAH3 Mutanten darauf hin, dass die Aminos{\"a}uren Histidin His330 und His454 entscheidend an der pH sensitiven Regulierung von SLAH3 beteiligt sind. Durch die erhobenen Daten konnten also entscheidende, neue Erkenntnisse {\"u}ber die Regulationsmechanismen von pflanzlichen Anionenkan{\"a}len auf molekularer Ebene gewonnen werden: Unter Standardbedingungen liegen SLAC1, SLAH2 und SLAH3 haupts{\"a}chlich als Dimer vor. Auf eine zytosolische Ans{\"a}uerung reagiert ausschließlich SLAH3 mit einer signifikanten st{\"o}chiometrischen Ver{\"a}nderung und liegt im aktiven Zustand vor Allem als Monomer vor. Der Oligomerisierungsgrad von SLAC1 und SLAH2 bleibt hingegen bei einer zytosolischen Ans{\"a}uerung unver{\"a}ndert. Ferner kommt es bei der Interaktion von SLAH3 mit SLAH1 oder SLAH4 zur Formierung eines Heterodimers, welches unbeeinflusst durch den zytosolischen pH bleibt. Im Gegensatz dazu bleiben die elektrisch inaktiven Untereinheiten SLAH1 und SLAH4 monomerisch und assemblieren ganz spezifisch nur mit SLAH3. Die hochaufl{\"o}sende Fluoreszenz-mikroskopie, insbesondere PALM erlaubt es also Heteromerisierungsereignisse und {\"A}nderungen im Poylmerisierungsgrad von Membranproteinen wie den SLAC/SLAHs auf molekularer Ebene zu untersuchen und l{\"a}sst so R{\"u}ckschl{\"u}sse auf physiologische Ereignisse zu.}, subject = {Fluoreszenzmikroskopie}, language = {de} } @article{RequierJowanowitschKallniketal.2020, author = {Requier, Fabrice and Jowanowitsch, Kim K. and Kallnik, Katharina and Steffan-Dewenter, Ingolf}, title = {Limitation of complementary resources affects colony growth, foraging behavior, and reproduction in bumble bees}, series = {Ecology}, volume = {101}, journal = {Ecology}, number = {3}, doi = {10.1002/ecy.2946}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211891}, pages = {e02946}, year = {2020}, abstract = {Resource availability in agricultural landscapes has been disturbed for many organisms, including pollinator species. Abundance and diversity in flower availability benefit bee populations; however, little is known about which of protein or carbohydrate resources may limit their growth and reproductive performance. Here, we test the hypothesis of complementary resource limitation using a supplemental feeding approach. We applied this assumption with bumble bees (Bombus terrestris), assuming that colony growth and reproductive performance should depend on the continuous supply of carbohydrates and proteins, through the foraging for nectar and pollen, respectively. We placed wild-caught bumble bee colonies along a landscape gradient of seminatural habitats, and monitored the colonies' weight, foraging activity, and reproductive performance during the whole colony cycle. We performed supplemental feeding as an indicator of landscape resource limitation, using a factorial design consisting of the addition of sugar water (carbohydrate, supplemented or not) crossed by pollen (protein, supplemented or not). Bumble bee colony dynamics showed a clear seasonal pattern with a period of growth followed by a period of stagnation. Higher abundance of seminatural habitats resulted in reducing the proportion of pollen foragers relative to all foragers in both periods, and in improving the reproductive performance of bumble bees. Interestingly, the supplemental feeding of sugar water positively affected the colony weight during the stagnation period, and the supplemental feeding of pollen mitigated the landscape effect on pollen collection investment. Single and combined supplementation of sugar water and pollen increased the positive effect of seminatural habitats on reproductive performance. This study reveals a potential colimitation in pollen and nectar resources affecting foraging behavior and reproductive performance in bumble bees, and indicates that even in mixed agricultural landscapes with higher proportions of seminatural habitats, bumble bee populations face resource limitations. We conclude that the seasonal management of floral resources must be considered in conservation to support bumble bee populations and pollination services in farmlands.}, language = {en} } @article{RuedenauerRaubenheimerKessnerBeierleinetal.2020, author = {Ruedenauer, Fabian A. and Raubenheimer, David and Kessner-Beierlein, Daniela and Grund-Mueller, Nils and Noack, Lisa and Spaethe, Johannes and Leonhardt, Sara D.}, title = {Best be(e) on low fat: linking nutrient perception, regulation and fitness}, series = {Ecology Letters}, volume = {23}, journal = {Ecology Letters}, number = {3}, doi = {10.1111/ele.13454}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208709}, pages = {545-554}, year = {2020}, abstract = {Preventing malnutrition through consuming nutritionally appropriate resources represents a challenge for foraging animals. This is due to often high variation in the nutritional quality of available resources. Foragers consequently need to evaluate different food sources. However, even the same food source can provide a plethora of nutritional and non-nutritional cues, which could serve for quality assessment. We show that bumblebees, Bombus terrestris , overcome this challenge by relying on lipids as nutritional cue when selecting pollen. The bees 'prioritised' lipid perception in learning experiments and avoided lipid consumption in feeding experiments, which supported survival and reproduction. In contrast, survival and reproduction were severely reduced by increased lipid contents. Our study highlights the importance of fat regulation for pollen foraging bumblebees. It also reveals that nutrient perception, nutrient regulation and reproductive fitness can be linked, which represents an effective strategy enabling quick foraging decisions that prevent malnutrition and maximise fitness.}, language = {en} } @article{AuerHuegelschaefferFischeretal.2020, author = {Auer, Daniela and H{\"u}gelsch{\"a}ffer, Sophie D. and Fischer, Annette B. and Rudel, Thomas}, title = {The chlamydial deubiquitinase Cdu1 supports recruitment of Golgi vesicles to the inclusion}, series = {Cellular Microbiology}, volume = {22}, journal = {Cellular Microbiology}, number = {5}, doi = {10.1111/cmi.13136}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208675}, pages = {e13136}, year = {2020}, abstract = {Chlamydia trachomatis is the main cause of sexually transmitted diseases worldwide. As obligate intracellular bacteria Chlamydia replicate in a membrane bound vacuole called inclusion and acquire nutrients for growth and replication from their host cells. However, like all intracellular bacteria, Chlamydia have to prevent eradication by the host's cell autonomous system. The chlamydial deubiquitinase Cdu1 is secreted into the inclusion membrane, facing the host cell cytosol where it deubiquitinates cellular proteins. Here we show that inactivation of Cdu1 causes a growth defect of C. trachomatis in primary cells. Moreover, ubiquitin and several autophagy receptors are recruited to the inclusion membrane of Cdu1-deficient Chlamydia . Interestingly, the growth defect of cdu1 mutants is not rescued when autophagy is prevented. We find reduced recruitment of Golgi vesicles to the inclusion of Cdu1 mutants indicating that vesicular trafficking is altered in bacteria without active deubiquitinase (DUB). Our work elucidates an important role of Cdu1 in the functional preservation of the chlamydial inclusion surface.}, language = {en} } @article{MayrPetersEardleyetal.2020, author = {Mayr, Antonia V. and Peters, Marcell K. and Eardley, Connal D. and Renner, Marion E. and R{\"o}der, Juliane and Steffan-Dewenter, Ingolf}, title = {Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera}, series = {Journal of Biogeography}, volume = {47}, journal = {Journal of Biogeography}, number = {4}, doi = {10.1111/jbi.13753}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208101}, pages = {854-865}, year = {2020}, abstract = {Aim: Temperature, food resources and top-down regulation by antagonists are considered as major drivers of insect diversity, but their relative importance is poorly understood. Here, we used cavity-nesting communities of bees, wasps and their antagonists to reveal the role of temperature, food resources, parasitism rate and land use as drivers of species richness at different trophic levels along a broad elevational gradient. Location: Mt. Kilimanjaro, Tanzania. Taxon: Cavity-nesting Hymenoptera (Hymenoptera: Apidae, Colletidae, Megachilidae, Crabronidae, Sphecidae, Pompilidae, Vespidae). Methods: We established trap nests on 25 study sites that were distributed over similar large distances in terms of elevation along an elevational gradient from 866 to 1788 m a.s.l., including both natural and disturbed habitats. We quantified species richness and abundance of bees, wasps and antagonists, parasitism rates and flower or arthropod food resources. Data were analysed with generalized linear models within a multi-model inference framework. Results: Elevational species richness patterns changed with trophic level from monotonically declining richness of bees to increasingly humped-shaped patterns for caterpillar-hunting wasps, spider-hunting wasps and antagonists. Parasitism rates generally declined with elevation but were higher for wasps than for bees. Temperature was the most important predictor of both bee and wasp host richness patterns. Antagonist richness patterns were also well predicted by temperature, but in contrast to host richness patterns, additionally by resource abundance and diversity. The conversion of natural habitats through anthropogenic land use, which included biomass removal, agricultural inputs, vegetation structure and percentage of surrounding agricultural habitats, had no significant effects on bee and wasp communities. Main conclusions: Our study underpins the importance of temperature as a main driver of diversity gradients in ectothermic organisms and reveals the increasingly important role of food resources at higher trophic levels. Higher parasitism rates at higher trophic levels and at higher temperatures indicated that the relative importance of bottom-up and top-down drivers of species richness change across trophic levels and may respond differently to future climate change.}, language = {en} } @phdthesis{HornneeBunz2020, author = {Horn [n{\´e}e Bunz], Melanie}, title = {The impact of Drosophila melanogaster`s endogenous clock on fitness: Influence of day length, humidity and food composition}, doi = {10.25972/OPUS-21141}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211415}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {We are living in a system that underlies permanent environmental changes due to the rotation of our planet. These changes are rhythmic with the most prominent one having a period of about 24 hours, but also shorter and longer rhythms characterize our environment. To cope with the ever-changing environmental conditions, it is thought to be beneficial if an organism can track and anticipate these changes. The so called endogenous clocks enable this and might provide a fitness advantage. To investigate and unravel the mechanism of endogenous clocks Chronobiologists have used different model organisms. In this thesis Drosophila melanogaster was used as model organism with its about 150 clock neurons representing the main endogenous clock of the fly in the central brain. The molecular mechanisms and the interlocked feedback loops with the main circadian key players like period, timeless, clock or cycle are under investigation since the 1970s and are characterized quite well so far. But the impact of a functional endogenous clock in combination with diverse factors and the resulting fitness advantages were analysed in only a few studies and remains for the most part unknown. Therefore the aim of this thesis was to unravel the impact of Drosophila melanogaster`s endogenous clock on the fitness of the fly. To achieve this goal different factors - like day length, humidity and food composition - were analyzed in wild type CS and three different period mutants, namely perL, perS and per01, that carry a point mutation altering or abolishing the free-running period of the fruit fly as well as a second arrhythmic strain, clkAR. In competition assay experiments wild type and clock mutant flies competed for up to 63 generations under a normal 24 hour rhythm with 12 hours light/day and 12 hours darkness/night (LD12:12) or T-cycles with 19 or 29 hours, according to the mutants free-running period, or constant light (LL) in case of the arrhythmic mutant as well as under natural-like outdoor conditions in two consecutive years. Overall the wild type CS strain was outcompeting the clock mutant strains independent of the environmental conditions. As the perL fly strain elongated their free-running period, the competition experiments were repeated with naturally cantonized new fly strains. With these experiments it could be shown that the genetic background of the fly strains - which are kept for decades in the lab, with backcrosses every few years - is very important and influences the fitness of flies. But also the day length impacts the fitness of the flies, enabling them to persist in higher percentage in a population under competition. Further factors that might influence the survival in a competing population were investigated, like e.g. mating preferences and locomotor activity of homo- and heterozygous females or sperm number of males transferred per mating. But these factors can still not explain the results in total and play no or only minor roles and show the complexity of the whole system with still unknown characteristics. Furthermore populations of flies were recorded to see if the flies exhibit a common locomotor activity pattern or not and indeed a population activity pattern could be recorded for the first time and social contact as a Zeitgeber could be verified for Drosophila melanogaster. In addition humidity and its impact on the flies´ fitness as well as a potential Zeitgeber was examined in this thesis. The flies experienced different relative humidities for eclosion and wing expansion and humidity cycle phase shifting experiments were performed to address these two different questions of fitness impact and potential Zeitgeber. The fruit fly usually ecloses in the morning hours when the relative humidity is quite high and the general assumption was that they do so to prevent desiccation. The results of this thesis were quite clear and demonstrate that the relative humidity has no great effect on the fitness of the flies according to successful eclosion or wing expansion and that temperature might be the more important factor. In the humidity cycle phase shifting experiments it could be revealed that relative humidity cannot act as a Zeitgeber for Drosophila melanogaster, but it influences and therefore masks the activity of flies by allowing or surpressing activity at specific relative humidity values. As final experiments the lifespan of wild type and clock mutant flies was investigated under different day length and with different food qualities to unravel the impact of these factors on the fitness and therefore survival of the flies on the long run. As expected the flies with nutrient-poor minimum medium died earlier than on the nutrient-rich maximum medium, but a small effect of day length could also be seen with flies living slightly longer when they experience environmental day length conditions resembling their free-running period. The experiments also showed a fitness advantage of the wild type fly strain against the clock mutant strains for long term, but not short term (about the first 2-3 weeks). As a conclusion it can be said that genetic variation is important to be able to adapt to changing environmental conditions and to optimize fitness and therefore survival. Having a functional endogenous clock with a free-running period of about 24 hours provides fitness advantages for the fruit fly, at least under competition. The whole system is very complex and many factors - known and unknown ones - play a role in this system by interacting on different levels, e.g. physiology, metabolism and/or behavior.}, subject = {Taufliege}, language = {en} } @article{AurastGradlPernesetal.2016, author = {Aurast, Anna and Gradl, Tobias and Pernes, Stefan and Pielstr{\"o}m, Steffen}, title = {Big Data und Smart Data in den Geisteswissenschaften}, series = {Bibliothek Forschung und Praxis}, volume = {40}, journal = {Bibliothek Forschung und Praxis}, number = {2}, issn = {1865-7648}, doi = {10.1515/bfp-2016-0033}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195237}, pages = {200-206}, year = {2016}, abstract = {Kein Abstract verf{\"u}gbar.}, language = {de} } @article{TrinklKaluzaWallaceetal.2020, author = {Trinkl, Moritz and Kaluza, Benjamin F. and Wallace, Helen and Heard, Tim A. and Keller, Alexander and Leonhardt, Sara D.}, title = {Floral Species Richness Correlates with Changes in the Nutritional Quality of Larval Diets in a Stingless Bee}, series = {Insects}, volume = {11}, journal = {Insects}, number = {2}, issn = {2075-4450}, doi = {10.3390/insects11020125}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200605}, pages = {125}, year = {2020}, abstract = {Bees need food of appropriate nutritional quality to maintain their metabolic functions. They largely obtain all required nutrients from floral resources, i.e., pollen and nectar. However, the diversity, composition and nutritional quality of floral resources varies with the surrounding environment and can be strongly altered in human-impacted habitats. We investigated whether differences in plant species richness as found in the surrounding environment correlated with variation in the floral diversity and nutritional quality of larval provisions (i.e., mixtures of pollen, nectar and salivary secretions) composed by the mass-provisioning stingless bee Tetragonula carbonaria (Apidae: Meliponini). We found that the floral diversity of larval provisions increased with increasing plant species richness. The sucrose and fat (total fatty acid) content and the proportion and concentration of the omega-6 fatty acid linoleic acid decreased, whereas the proportion of the omega-3 fatty acid linolenic acid increased with increasing plant species richness. Protein (total amino acid) content and amino acid composition did not change. The protein to fat (P:F) ratio, known to affect bee foraging, increased on average by more than 40\% from plantations to forests and gardens, while the omega-6:3 ratio, known to negatively affect cognitive performance, decreased with increasing plant species richness. Our results suggest that plant species richness may support T. carbonaria colonies by providing not only a continuous resource supply (as shown in a previous study), but also floral resources of high nutritional quality.}, language = {en} } @article{PrustyChowdhuryGulveetal.2018, author = {Prusty, Bhupesh K. and Chowdhury, Suvagata R. and Gulve, Nitish and Rudel, Thomas}, title = {Peptidase Inhibitor 15 (PI15) Regulates Chlamydial CPAF Activity}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {8}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {183}, issn = {2235-2988}, doi = {10.3389/fcimb.2018.00183}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196918}, year = {2018}, abstract = {Obligate intracellular pathogenic Chlamydia trachomatis express several serine proteases whose roles in chlamydial development and pathogenicity are not completely understood. The chlamydial protease CPAF is expressed during the replicative phase of the chlamydial developmental cycle and is secreted into the lumen of the Chlamydia-containing vacuole called inclusion. How the secreted protease is activated in the inclusion lumen is currently not fully understood. We have identified human serine peptidase inhibitor PI15 as a potential host factor involved in the regulation of CPAF activation. Silencing expression as well as over expression of PI15 affected normal development of Chlamydia. PI15 was transported into the chlamydial inclusion lumen where it co-localized with CPAF aggregates. We show that PI15 binds to the CPAF zymogen and potentially induces CPAF protease activity at low concentrations. However, at high concentrations PI15 inhibits CPAF activity possibly by blocking its protease domain. Our findings shed light on a new aspect of chlamydial host co-evolution which involves the recruitment of host cell proteins into the inclusion to control the activation of bacterial proteases like CPAF that are important for the normal development of Chlamydia.}, language = {en} } @article{AnelliOrdasKneitzetal.2018, author = {Anelli, Viviana and Ordas, Anita and Kneitz, Susanne and Sagredo, Leonel Munoz and Gourain, Victor and Schartl, Manfred and Meijer, Annemarie H. and Mione, Marina}, title = {Ras-Induced miR-146a and 193a Target Jmjd6 to Regulate Melanoma Progression}, series = {Frontiers in Genetics}, volume = {9}, journal = {Frontiers in Genetics}, number = {675}, issn = {1664-8021}, doi = {10.3389/fgene.2018.00675}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196963}, year = {2018}, abstract = {Ras genes are among the most commonly mutated genes in human cancer; yet our understanding of their oncogenic activity at the molecular mechanistic level is incomplete. To identify downstream events that mediate ras-induced cellular transformation in vivo, we analyzed global microRNA expression in three different models of Ras-induction and tumor formation in zebrafish. Six microRNAs were found increased in Ras-induced melanoma, glioma and in an inducible model of ubiquitous Ras expression. The upregulation of the microRNAs depended on the activation of the ERK and AKT pathways and to a lesser extent, on mTOR signaling. Two Ras-induced microRNAs (miR-146a and 193a) target Jmjd6, inducing downregulation of its mRNA and protein levels at the onset of Ras expression during melanoma development. However, at later stages of melanoma progression, jmjd6 levels were found elevated. The dynamic of Jmjd6 levels during progression of melanoma in the zebrafish model suggests that upregulation of the microRNAs targeting Jmjd6 may be part of an anti-cancer response. Indeed, triple transgenic fish engineered to express a microRNA-resistant Jmjd6 from the onset of melanoma have increased tumor burden, higher infiltration of leukocytes and shorter melanoma-free survival. Increased JMJD6 expression is found in several human cancers, including melanoma, suggesting that the up-regulation of Jmjd6 is a critical event in tumor progression. The following link has been created to allow review of record GSE37015: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=jjcrbiuicyyqgpc\&acc=GSE37015.}, language = {en} } @article{DandekarEisenreich2015, author = {Dandekar, Thomas and Eisenreich, Wolfgang}, title = {Host-adapted metabolism and its regulation in bacterial pathogens}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {5}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {28}, issn = {2235-2988}, doi = {10.3389/fcimb.2015.00028}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196876}, year = {2015}, abstract = {No abstract available.}, language = {en} } @article{GrebinykPrylutskaBuchelnikovetal.2019, author = {Grebinyk, Anna and Prylutska, Svitlana and Buchelnikov, Anatoliy and Tverdokhleb, Nina and Grebinyk, Sergii and Evstigneev, Maxim and Matyshevska, Olga and Cherepanov, Vsevolod and Prylutskyy, Yuriy and Yashchuk, Valeriy and Naumovets, Anton and Ritter, Uwe and Dandekar, Thomas and Frohme, Marcus}, title = {C60 fullerene as an effective nanoplatform of alkaloid Berberine delivery into leukemic cells}, series = {Pharmaceutics}, volume = {11}, journal = {Pharmaceutics}, number = {11}, issn = {1999-4923}, doi = {10.3390/pharmaceutics11110586}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193216}, pages = {586}, year = {2019}, abstract = {A herbal alkaloid Berberine (Ber), used for centuries in Ayurvedic, Chinese, Middle-Eastern, and native American folk medicines, is nowadays proved to function as a safe anticancer agent. Yet, its poor water solubility, stability, and bioavailability hinder clinical application. In this study, we have explored a nanosized carbon nanoparticle—C60 fullerene (C60)—for optimized Ber delivery into leukemic cells. Water dispersions of noncovalent C60-Ber nanocomplexes in the 1:2, 1:1, and 2:1 molar ratios were prepared. UV-Vis spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM) evidenced a complexation of the Ber cation with the negatively charged C60 molecule. The computer simulation showed that π-stacking dominates in Ber and C\(_{60}\) binding in an aqueous solution. Complexation with C\(_{60}\) was found to promote Ber intracellular uptake. By increasing C\(_{60}\) concentration, the C\(_{60}\)-Ber nanocomplexes exhibited higher antiproliferative potential towards CCRF-CEM cells, in accordance with the following order: free Ber < 1:2 < 1:1 < 2:1 (the most toxic). The activation of caspase 3/7 and accumulation in the sub-G1 phase of CCRF-CEM cells treated with C\(_{60}\)-Ber nanocomplexes evidenced apoptosis induction. Thus, this study indicates that the fast and easy noncovalent complexation of alkaloid Ber with C\(_{60}\) improved its in vitro efficiency against cancer cells.}, language = {en} } @article{PaponovDindas Krol etal.2019, author = {Paponov, Ivan A. and Dindas , Julian and Kr{\´o}l , Elżbieta and Friz, Tatyana and Budnyk, Vadym and Teale, William and Paponov, Martina and Hedrich , Rainer and Palme, Klaus}, title = {Auxin-Induced plasma membrane depolarization is regulated by Auxin transport and not by AUXIN BINDING PROTEIN1}, series = {Frontiers in Plant Science}, volume = {9}, journal = {Frontiers in Plant Science}, issn = {1664-462X}, doi = {10.3389/fpls.2018.01953}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195914}, year = {2019}, abstract = {Auxin is a molecule, which controls many aspects of plant development through both transcriptional and non-transcriptional signaling responses. AUXIN BINDING PROTEIN1 (ABP1) is a putative receptor for rapid non-transcriptional auxin-induced changes in plasma membrane depolarization and endocytosis rates. However, the mechanism of ABP1-mediated signaling is poorly understood. Here we show that membrane depolarization and endocytosis inhibition are ABP1-independent responses and that auxin-induced plasma membrane depolarization is instead dependent on the auxin influx carrier AUX1. AUX1 was itself not involved in the regulation of endocytosis. Auxin-dependent depolarization of the plasma membrane was also modulated by the auxin efflux carrier PIN2. These data establish a new connection between auxin transport and non-transcriptional auxin signaling.}, language = {en} } @article{NadellaMohantySharmaetal.2018, author = {Nadella, Vinod and Mohanty, Aparna and Sharma, Lalita and Yellaboina, Sailu and Mollenkopf, Hans-Joachim and Mazumdar, Varadendra Balaji and Palaparthi, Ramesh and Mylavarapu, Madhavi B. and Maurya, Radheshyam and Kurukuti, Sreenivasulu and Rudel, Thomas and Prakash, Hridayesh}, title = {Inhibitors of Apoptosis Protein Antagonists (Smac Mimetic Compounds) Control Polarization of Macrophages during Microbial Challenge and Sterile Inflammatory Responses}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {1792}, issn = {1664-3224}, doi = {10.3389/fimmu.2017.01792}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197484}, year = {2018}, abstract = {Apoptosis is a physiological cell death process essential for development, tissue homeostasis, and for immune defense of multicellular animals. Inhibitors of apoptosis proteins (IAPs) regulate apoptosis in response to various cellular assaults. Using both genetic and pharmacological approaches we demonstrate here that the IAPs not only support opportunistic survival of intracellular human pathogens like Chlamydia pneumoniae but also control plasticity of iNOS+ M1 macrophage during the course of infection and render them refractory for immune stimulation. Treatment of Th1 primed macrophages with birinapant (IAP-specific antagonist) inhibited NO generation and relevant proteins involved in innate immune signaling. Accordingly, birinapant promoted hypoxia, angiogenesis, and tumor-induced M2 polarization of iNOS+ M1 macrophages. Interestingly, birinapant-driven changes in immune signaling were accompanied with changes in the expression of various proteins involved in the metabolism, and thus revealing the new role of IAPs in immune metabolic reprogramming in committed macrophages. Taken together, our study reveals the significance of IAP targeting approaches (Smac mimetic compounds) for the management of infectious and inflammatory diseases relying on macrophage plasticity.}, language = {en} } @phdthesis{OlivaresBaerwald2020, author = {Olivares-Baerwald, Silvana}, title = {Die Rolle von Calcineurin im Nukleus von Kardiomyozyten und ein innovativer Inhibitor als neuer therapeutischer Ansatz bei kardialer Hypertrophie}, doi = {10.25972/OPUS-20808}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208080}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Die Calcineurin/NFAT-Signalkaskade spielt eine wichtige Rolle bei der Entwicklung einer kardialen Hypertrophie. Im Zytoplasma von Kardiomyozyten wird die Phosphatase Calcineurin nach Stimulierung der Zellen, z. B. durch Dehnungsreize, Angiotensin II (Ang II) oder Endothelin I (ET-1), und einen daraus folgenden intrazellul{\"a}ren Ca2+-Strom aktiviert. Dies f{\"u}hrt zur Dephosphorylierung von NFAT und zu dessen nukle{\"a}rer Translokation. In fr{\"u}heren Arbeiten von Ritter et al. wurden sowohl eine nukle{\"a}re Lokalisationssequenz (NLS) als auch eine nukle{\"a}re Exportsequenz (NES) innerhalb von Calcineurin identifiziert, die den Transport von Calcineurin zwischen dem Zytoplasma und dem Nukleus erm{\"o}glichen. Basierend auf diesen Ergebnissen wurde das Import Blocking Peptid (IBP) entwickelt. Dieses Peptid entspricht der NLS von Calcineurin und blockiert die Calcineurin-Bindungsstellen des Shuttleproteins (Karyopherins) Importin β1. So wird die Translokation von Calcineurin in den Nukleus unterbunden und die Signalkaskade zur Aktivierung von Hypertrophie-Genen in Kardiomyozyten unterbrochen. Dabei blieb die Phosphatase-Aktivit{\"a}t von Calcineurin unbeeinflusst. Eines der Ziele dieser Arbeit war, IBP weiter zu optimieren und den „proof of principle" auch in vivo zu f{\"u}hren. Hierf{\"u}r wurden u. a. ein geeignetes L{\"o}sungsmittel bestimmt (biokompatibel und an die Peptidcharakteristika angepasst), die Peptidstruktur modifiziert (Erh{\"o}hung der Spezifit{\"a}t/Wirksamkeit) und die erforderliche Dosis weiter eingegrenzt (Belastungs- und Kostenreduktion). Unter Verwendung einer TAMRA-markierten Wirkstoffvariante konnten der Weg des Peptids in M{\"a}usen nachverfolgt und die Ausscheidung quantifiziert werden. Aufbauend auf den Ergebnissen von Burkard et al., die die Entstehung einer konstitutiv-aktiven und nukle{\"a}ren Calcineurin-Isoform nach proteolytischer Spaltung durch Calpain nachwiesen, wurde die Rolle von Calcineurin im Zellkern genauer untersucht. Außerdem sollte die Frage beantwortet werden, wie ({\"u}ber Calcineurin?) die Herzmuskelzelle zwischen Calciumschwankungen im Zuge der Exzitations-Kontraktions-Kopplung (ECC) und vergleichsweise schwachen Calciumsignalen zur Transkriptionsteuerung unterscheidet. Mit Hilfe von nukle{\"a}ren Calcineurin-Mutanten, die einen Defekt in der Ca2+-Bindung aufwiesen, konnte die Bedeutung von Calcineurin als Calciumsensor f{\"u}r die NFAT-abh{\"a}ngige Transkription nachgewiesen werden. Im Mausmodell waren unter Hypertrophie-Bedingungen die Ca2+-Transienten in der nukle{\"a}ren Mikrodom{\"a}ne signifikant st{\"a}rker als im Zytosol, wodurch die Hypothese, dass die Aktivierung der Calcineurin/NFAT-Signalkaskade unabh{\"a}ngig von zytosolischem Ca2+ erfolgt, gest{\"u}tzt wird. Messungen von nukle{\"a}ren und zytosolischen Ca2+-Transienten in IP3-Sponge-M{\"a}usen zeigten im Vergleich zu Wildtyp-M{\"a}usen keine Erh{\"o}hung des Ca2+-Spiegels w{\"a}hrend der Diastole, was auf eine Rolle von Inositoltrisphosphat (IP3) in der Signalkaskade deutet. Außerdem zeigten isolierte Zellkerne ventrikul{\"a}rer adulter Kardiomyozyten eine erh{\"o}hte Expression des IP3-Rezeptors 2 (IP3R2) nach Ang II-Stimulierung. Diese gesteigerte Expression war abh{\"a}ngig von der Calcineurin/NFAT-Kaskade und bestand sogar 3 Wochen nach Entfernung des Ang II-Stimulus fort. Zusammenfassend l{\"a}sst sich sagen, dass nukle{\"a}res Calcineurin als ein Ca2+-Sensor agiert, dass die lokale Ca2+-Freisetzung im Kern {\"u}ber IP3-Rezeptoren detektiert wird und dass dies im Zusammenspiel mit NFAT die Transkription von Hypertrophiegenen initiiert.}, subject = {kardiale Hypertrophie}, language = {de} } @phdthesis{Hofrichter2020, author = {Hofrichter, Michaela Angelika Hedwig}, title = {Charakterisierung von angeborenen H{\"o}rst{\"o}rungen mit Hilfe von Hochdurchsatz-Sequenziermethoden}, doi = {10.25972/OPUS-18533}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-185331}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Fast 500 Millionen Menschen weltweit sind von einer H{\"o}rst{\"o}rung betroffen. Es wird sogar angenommen, dass diese Anzahl laut der Weltgesundheitsorganisation (WHO) noch steigen und 2050 jeder zehnte Mensch eine H{\"o}rst{\"o}rung aufweisen wird. Mindestens in 50\% aller F{\"a}lle ist die H{\"o}rst{\"o}rung genetisch bedingt. Durch die j{\"u}ngsten Fortschritte der Sequenzierungstechnologien hat die genetische Analyse von H{\"o}rst{\"o}rungen an Bedeutung gewonnen, vor allem hinsichtlich Familienplanung, geeigneter Therapien und zuk{\"u}nftiger m{\"o}glichen Therapieans{\"a}tzen, um das H{\"o}rverm{\"o}gen wiederherzustellen. Die folgende Arbeit stellt 155 famili{\"a}re F{\"a}lle vor, die genetisch untersucht wurden. Diese F{\"a}lle konnten in zwei Kohorten unterteilt werden. Eine Kohorte (n = 74) umfasste Patienten mit kaukasischem Hintergrund, w{\"a}hrend die andere Kohorte (n = 81) Patienten beinhaltete, die aus dem Iran rekrutiert wurden. F{\"u}r die Untersuchung wurde zum einen eine Panel-Analyse mit dem TruSight One Panel (Illumina, San Diego, USA) und zum anderen eine Exom-Sequenzierung durchgef{\"u}hrt. Anschließend wurden die Daten mit Analyse-Programmen wie GensearchNGS (PhenoSystems, Wallonia, Belgien) ausgewertet. Insgesamt konnte f{\"u}r 55\% aller F{\"a}lle eine pathogene oder wahrscheinlich pathogene Variante durch Next Generation Sequencing diagnostiziert werden. Die meisten der gel{\"o}sten F{\"a}lle (ca. 73\%) stammten aus der iranischen Kohorte, was durch elterliche Blutsverwandtschaft und erh{\"o}hte Inzidenz von H{\"o}rst{\"o}rungen im Iran zu erkl{\"a}ren ist. 27\% der gel{\"o}sten F{\"a}lle geh{\"o}rten der zweiten Kohorte an. Mutationen in den Genen MYO15A, LHFPL5, TECTA und SLC26A4 konnten {\"u}berwiegend bei iranischen Patienten identifiziert werden. Varianten im Gen TECTA als auch im Gen SLC26A4 wurden ebenfalls in der kaukasischen Kohorte identifiziert. Beide Ethnien wiesen jeweils ein eigenes Mutationsspektrum auf. Jedoch wurden in beiden Gruppen {\"U}berschneidungen im klinischen Bild durch pathogene Varianten in einer Vielzahl von H{\"o}rst{\"o}rungsgenen, sowie unterschiedliche klinische Ph{\"a}notypen, deren Ursache pathogene Varianten im gleichen H{\"o}rst{\"o}rungsgen zugrunde liegen, und famili{\"a}re Locus-Heterogenit{\"a}t beobachtet.. In dieser Arbeit konnte eine De Novo Mutation im CEACAM16-Gen (DFNA4B) best{\"a}tigt und der Effekt von einer wiederholt betroffenen Aminos{\"a}ure im S1PR2-Gen (DFNB68) beschrieben werden. Dar{\"u}ber hinaus wurden mehrere Patienten mit X-chromosomalem H{\"o}rverlust aufgrund von Defekten im POU3F4-Gen (DFNX2) und Deletionen im SMPX-Gen (DFNX4) diagnostiziert. Zus{\"a}tzlich konnte mit Hilfe einer Exom-basierten Copy Number Variation-Analyse eine Deletion im OTOA-Gen (DFNB22) gefunden werden, welche sich bis in die Tandempseudogenregion erstreckte. Diese Untersuchung zeigt die enormen M{\"o}glichkeiten zur Detektion von Mutationen bei heterogenen Erkrankungen durch Anwendung von Next Generation Sequencing. Weiterhin konnte eine intragenische Deletion im Gen COL9A1 identifiziert werden, die im Zusammenhang mit einer scheinbar isolierten H{\"o}rst{\"o}rung steht und durch den komplexen Umlagerungsmechanismus FoSTeS/MMBIR (Fork Stalling und Template Switching/Microhomology-mediated Break-induced Replication) entstand, der so bei H{\"o}rst{\"o}rungen noch nicht beschrieben wurde. Auf der Suche nach Genen, die bisher noch nicht mit H{\"o}rst{\"o}rungen assoziiert werden konnten, wurden acht Familien in eine Kandidatengenuntersuchung miteinbezogen und eine Exom-weite Analyse durchgef{\"u}hrt. Bei f{\"u}nf Familien konnte noch keine urs{\"a}chliche Variante identifiziert werden. Jedoch wurde bei drei Familien mit einer autosomal dominanten Schwerh{\"o}rigkeit eine genetische Ursache identifiziert und TECTB, ATP11A und THBS2 konnten als Kandidatengene ermittelt werden. Diese Arbeit zeigt, wie wichtig es ist, die kausale Variante bei H{\"o}rst{\"o}rungspatienten zu detektieren. Eine genetische Diagnostik erm{\"o}glicht eine endg{\"u}ltige Diagnose eines Syndroms, ist f{\"u}r die Klassifizierung der H{\"o}rst{\"o}rung notwendig und tr{\"a}gt zu einer zuk{\"u}nftigen Therapie der Patienten bei.}, subject = {H{\"o}rst{\"o}rungen}, language = {de} } @phdthesis{Rost2020, author = {Rost, Isabell}, title = {Gezielte Anreicherungs- und neue DNA-Sequenzierungsstrategien f{\"u}r die molekulare Analyse von Fanconi-An{\"a}mie-Genen}, doi = {10.25972/OPUS-15109}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151096}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Fanconi-An{\"a}mie (FA) ist, mit Ausnahme von Mutationen in FANCR/RAD51, eine autosomal-rezessive oder X-chromosomal vererbte Krankheit, die sich durch eine ausgesprochene klinische als auch genetische Heterogenit{\"a}t auszeichnet. Neben einem fortschreitenden Knochenmarksversagen z{\"a}hlen zu den typischen Merkmalen eine Vielzahl an angeborenen Fehlbildungen, wie beispielsweise Radialstrahlanomalien, Minderwuchs oder Pigmentierungsst{\"o}rungen. Zudem besteht f{\"u}r FA-Patienten ein {\"u}berdurchschnittlich hohes Risiko bereits in jungen Jahren an akuter myeloischer Leuk{\"a}mie oder soliden Tumoren zu erkranken. Bislang konnten in 21 FA-Genen (FANCA, -B, -C, - D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U oder -V) krankheitsverursachende Mutationen identifiziert werden, deren Proteinprodukte maßgeblich an der Aufrechterhaltung der Genomstabilit{\"a}t beteiligt sind und Komponenten des FA/BRCA-DNA-Reparaturweges darstellen. In der klassischen FA-Mutationsanalyse kommen meist Sanger-Sequenzierungen sowie MLPA- und Immunblot-Analysen zum Einsatz. Da im Wesentlichen keine Genotyp-Ph{\"a}notyp-Korrelation besteht, gestaltet sich, gerade bei seltenen FA-Komplementationsgruppen, der Nachweis von krankheitsverursachenden Mutationen oftmals sehr zeit- und kostenintensiv. W{\"a}hrend der letzten Jahre wurden verschiedene Strategien zur Anreicherung und Sequenzierung entwickelt, welche die parallele Sequenzanalyse einzelner ausgew{\"a}hlter Gene, ganzer Exome oder sogar des gesamten Genoms und somit eine kosten- und zeiteffiziente Mutationsanalyse erm{\"o}glichen. In der vorliegenden Arbeit wurden unterschiedliche Anreicherungsmethoden mit anschließender Hochdurchsatzsequenzierung auf ihre Anwendbarkeit in der molekulargenetischen FA-Diagnostik getestet, um klassische Mutationsanalyse-Methoden zu erg{\"a}nzen oder m{\"o}glicherweise sogar ganz ersetzen zu k{\"o}nnen. Der erste Teil der Arbeit befasste sich mit der Etablierung eines FA-spezifischen Genpanels zur Genotypisierung von FA-Patienten. Nachdem die Methode zun{\"a}chst anhand von FA-Patienten mit bekannten Mutationen optimiert werden musste, erwies sie sich als effizienter Ansatz zum Nachweis krankheitsverursachender Mutationen bei FA-Patienten unbekannter Komplementationsgruppe. Durch die FA-Panelanalyse konnten 37 von 47 unklassifizierten Patienten einer FA-Komplementationsgruppe zugeordnet werden, indem deren kausalen Mutationen bestimmt wurden. In einem weiteren Ansatz sollte die Anwendbarkeit eines kommerziellen Anreicherungspanels zur FA-Diagnostik untersucht werden. Auch hier konnte ein Großteil der krankheitsverursachenden Mutationen von f{\"u}nf bekannten wie auch 13 nicht zugeordneten FA-Patienten detektiert und somit eine molekulargenetische Diagnose bei neun weiteren, zuvor unklassifizierten FA-Patienten, gestellt werden. Ferner wurden sechs ausgew{\"a}hlte Patienten, zus{\"a}tzlich zur Panelanreicherung, per Exomanalyse untersucht. Zum einen konnten Mutationen in bekannten FA-Genen best{\"a}tigt oder neu identifiziert werden. Zum anderen wurden auch potentiell pathogene Mutationen in DNA-Reparaturgenen außerhalb des FA/BRCA-Signalweges bei zwei Patienten mit unbest{\"a}tigter Verdachtsdiagnose FA verifiziert. So wurde bei mehreren Mitgliedern einer Familie mit unterschiedlichen Tumorerkrankungen eine zuvor unbeschriebene homozygote Nonsense-Mutation in der BER-Glykosylase NTHL1 nachgewiesen, f{\"u}r welche bislang erst zwei pathogene Mutationen als Ausl{\"o}ser eines neuen Krebssyndroms bekannt sind. Bei einem weiteren Patienten wurden compound-heterozygote Mutationen in RPA1 detektiert, ein Gen f{\"u}r das bislang noch kein Krankheitsbild bekannt ist. Mit Hilfe der drei verschiedenen Anreicherungsstrategien konnten insgesamt 47 von 60 unklassifizierten FA-Patienten 13 verschiedenen Komplementationsgruppen eindeutig zugeordnet werden. Es zeigte sich dabei ein breites Spektrum an neuen, bislang unbeschriebenen FA-Mutationen. Den gr{\"o}ßten Anteil an der Gesamtzahl der nachgewiesenen Mutationen hatten Spleißmutationen, die auf eine Auswirkung auf das kanonische Spleißmuster untersucht wurden, um einen pathogenen Effekt nachweisen zu k{\"o}nnen. Weiterhin schloss die Arbeit die Charakterisierung einzelner FA-Patienten bzw. Komplementationsgruppen mit ein. Dazu z{\"a}hlen die seltenen Untergruppen FA-T und FA-Q, f{\"u}r die jeweils ein neuer Patient identifiziert werden konnte. Durch die funktionelle Charakterisierung der dritten jemals beschriebenen FA-Q-Patientin konnten Einblicke in das Zusammenspiel der Reparatur von DNA-Quervernetzungen und der Nukleotidexzisionsreparatur gewonnen und die ph{\"a}notypische Variabilit{\"a}t von FA durch die subjektive als auch zellul{\"a}re UV-Sensitivit{\"a}t der Patientin erg{\"a}nzt werden. Dar{\"u}ber hinaus konnte das Mutationsspektrum in FA-I sowie FA-D2 erweitert werden. Eine genauere Untersuchung der Pseudogenregionen von FANCD2 erm{\"o}glichte dabei die gezielte Mutationsanalyse des Gens. Insgesamt konnten die Ergebnisse dieser Arbeit dazu beitragen, das Mutationsspektrum in FA zu erweitern und durch die Identifizierung und Charakterisierung einzelner Patienten neue Einblicke in verschiedene Komponenten des FA/BRCA-Signalweges zu erhalten. Es zeigte sich, dass neue DNA-Sequenzierungsstrategien in der FA-Diagnostik eingesetzt werden k{\"o}nnen, um eine effiziente Mutationsanalyse zu gew{\"a}hrleisten und klassische Methoden in Teilbereichen zu ersetzen.}, subject = {Fanconi-An{\"a}mie}, language = {de} } @phdthesis{Eidel2020, author = {Eidel, Matthias T. A. M.}, title = {Training Effects of a Tactile Brain-Computer Interface System During Prolonged Use by Healthy And Motor-Impaired People}, doi = {10.25972/OPUS-20851}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208511}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Background - Brain-Computer Interfaces (BCI) enable their users to interact and communicate with the environment without requiring intact muscle control. To this end, brain activity is directly measured, digitized and interpreted by the computer. Thus, BCIs may be a valuable tool to assist severely or even completely paralysed patients. Many BCIs, however, rely on neurophysiological potentials evoked by visual stimulation, which can result in usability issues among patients with impaired vision or gaze control. Because of this, several non-visual BCI paradigms have been developed. Most notably, a recent study revealed promising results from a tactile BCI for wheelchair control. In this multi-session approach, healthy participants used the BCI to navigate a simulated wheelchair through a virtual apartment, which revealed not only that the BCI could be operated highly efficiently, but also that it could be trained over five sessions. The present thesis continues the research on this paradigm in order to - confirm its previously reported high performance levels and trainability - reveal the underlying factors responsible for observed performance increases - establish its feasibility among potential impaired end-users Methods - To approach these goals, three studies were conducted with both healthy participants and patients with amyotrophic lateral sclerosis (ALS). Brain activity during BCI operation was recorded via electroencephalography (EEG) and interpreted using a machine learning-based linear classifier. Wheelchair navigation was executed according to the classification results and visualized on a monitor. For offline statistical analysis, neurophysiological features were extracted from EEG data. Subjective data on usability were collected from all participants. Two specialized experiments were conducted to identify factors for training. Results and Discussion - Healthy participants: Results revealed positive effects of training on BCI performances and their underlying neurophysiological potentials. The paradigm was confirmed to be feasible and (for a non-visual BCI) highly efficient for most participants. However, some had to be excluded from analysis of the training effects because they could not achieve meaningful BCI control. Increased somatosensory sensitivity was identified as a possible mediator for training-related performance improvements. Participants with ALS: Out of seven patients with various stages of ALS, five could operate the BCI with accuracies significantly above chance level. Another ALS patient in a state of near-complete paralysis trained with the BCI for several months. Although no effects of training were observed, he was consistently able to operate the system above chance level. Subjective data regarding workload, satisfaction and other parameters were reported. Significance - The tactile BCI was evaluated on the example of wheelchair control. In the future, it could help impaired patients to regain some lost mobility and self-sufficiency. Further, it has the potential to be adapted to other purposes, including communication. Once visual BCIs and other assistive technologies fail for patients with (progressive) motor impairments, vision-independent paradigms such as the tactile BCI may be among the last remaining alternatives to interact with the environment. The present thesis has strongly confirmed the general feasibility of the tactile paradigm for healthy participants and provides first clues about the underlying factors of training. More importantly, the BCI was established among potential end-users with ALS, providing essential external validity.}, subject = {Myatrophische Lateralsklerose}, language = {en} } @phdthesis{Seibold2020, author = {Seibold, Marcel}, title = {Funktionelle Charakterisierung des Ras family small GTP binding protein RAL im Multiplen Myelom}, doi = {10.25972/OPUS-20800}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208003}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Die monoklonale Proliferation maligner Plasmazellen im Knochenmark ist charakteristisch f{\"u}r das multiple Myelom (MM) und kann bei Erkrankten zu St{\"o}rungen in der H{\"a}matopoese sowie zu Knochenl{\"a}sionen und Niereninsuffizienz f{\"u}hren. Die Weiterentwicklung und der Einsatz neuer Therapieoptionen konnten das {\"U}berleben von MM-Patienten zwar erheblich verbessern, jedoch gilt diese Krankheit weiterhin als unheilbar. Onkogene Mutationen und das Knochenmarkmikromilieu f{\"u}hren in MM-Zellen zur Entstehung eines onkogenen Signalnetzwerks, das das Wachstum und {\"U}berleben der Zellen aufrechterh{\"a}lt. Mutationen der GTPase RAS treten bei bis zu 50 \% der MM-Patienten auf und tragen zum {\"U}berleben von MM-Zellen bei. Trotz der H{\"a}ufigkeit und Bedeutsamkeit von onkogenem RAS, auch in anderen Tumorentit{\"a}ten, ist die GTPase nach wie vor therapeutisch nicht angreifbar. Die GTPase RAL aus der Familie der RAS-GTPasen wird als Downstream-Effektor von RAS angesehen, der damit ebenfalls zur Aufrechterhaltung des Tumorzell{\"u}berlebens beitragen k{\"o}nnte. In einigen Tumorentit{\"a}ten konnte bisher gezeigt werden, dass eine {\"U}berexpression von RAL in den Tumorzellen vorliegt und die Proliferation und Apoptose von Tumorzellen durch RAL beeinflusst wird. Daher stellte sich die Frage, ob RAL im MM ebenfalls das {\"U}berleben von Tumorzellen beeinflusst und ob eine direkte Verbindung zwischen onkogenem RAS und RAL besteht. In dieser Arbeit wurde die funktionelle Rolle von RAL sowie dessen Zusammenhang mit onkogenem RAS im MM untersucht. Hierbei konnte eine {\"U}berexpression von RAL in MM-Zellen im Vergleich zu MGUS oder normalen Plasmazellen beobachtet werden. In Knockdown-Analysen wurde gezeigt, dass RAL {\"u}berlebensnotwendig f{\"u}r MM-Zellen ist. Dabei wurde in Western Blot-Analysen festgestellt, dass diese {\"U}berlebenseffekte unabh{\"a}ngig von MAPK/ERK-Signaling vermittelt werden. Es konnte teilweise jedoch eine Abh{\"a}ngigkeit von der AKT-Aktivit{\"a}t beobachtet werden. Da RAL-Knockdown Einfluss auf das {\"U}berleben von MM-Zellen hat, wurde eine pharmakologische Inhibition von RAL durch den Inhibitor RBC8 untersucht. RBC8 zeigte in h{\"o}heren Dosen nur bei einem Teil der MM-Zelllinien eine Wirkung auf das Zell{\"u}berleben sowie auf die RAL-Aktivierung. Die Weiterentwicklung potenter RAL-Inhibitoren ist daher f{\"u}r eine klinische Translation einer RAL-Inhibition von großer Bedeutung. Zur Untersuchung des Zusammenhangs zwischen onkogenem RAS und der RAL-Aktivierung wurden RAL-Pulldown-Analysen nach Knockdown von onkogenem RAS durchgef{\"u}hrt. In diesen Experimenten wurde keine Abh{\"a}ngigkeit der RAL-Aktivierung von onkogenem RAS festgestellt. Dar{\"u}ber hinaus zeigten Genexpressionsanalysen nach RAS- bzw. RAL-Knockdown unterschiedliche Genexpressionsprofile. In Massenspektrometrie-Analysen wurden m{\"o}gliche Effektoren, die mit RAL an der Beeinflussung des Zell{\"u}berlebens beteiligt sein k{\"o}nnten, untersucht. Hierbei wurden die Komponenten des Exozyst-Komplexes EXO84 und SEC5 als Interaktionspartner von RAL identifiziert. Nachdem gezeigt wurde, dass RAL ausschlaggebend f{\"u}r das {\"U}berleben von MM-Zellen ist, wurde eine Kombination von RAL-Knockdown mit klinisch relevanten Wirkstoffen analysiert. Diese zeigte bei der Kombination mit PI3K oder AKT-Inhibitoren verst{\"a}rkte Effekte auf das Zell{\"u}berleben der MM-Zellen. Zusammenfassend wurde die Bedeutung von RAL f{\"u}r das {\"U}berleben von Tumorzellen im MM gezeigt und RAL als potentielles therapeutisches Target im MM beschrieben, welches unabh{\"a}ngig von onkogenem RAS reguliert wird.}, subject = {Kleine GTP-bindende Proteine}, language = {de} } @phdthesis{Seitz2020, author = {Seitz, Nicola}, title = {Bee demise and bee rise: From honey bee colony losses to finding measures for advancing entire bee communities}, doi = {10.25972/OPUS-18418}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184180}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {My dissertation comprises three studies: (1) an assessment of honey bee colony losses in the USA between 2014 and 2015, (2) an exploration of the potential of reclaimed sand mines as bee habitat, and (3) an evaluation of native and non-native pollinator friendly plants in regard to their attraction to bees. While the first study focuses on honey bees, the latter two studies primarily take wild bees or entire bee communities in focus. The study on honey bee colony losses was conducted within the framework of the Bee Informed Partnership (BIP, beeinformed.org) and aligns with the annual colony loss surveys which have been conducted in the USA since the winter of 2006/2007. It was the fourth year for which summer and annual losses were calculated in addition to winter losses. Among participants, backyard beekeepers were the largest group (n = 5690), although sideline (n = 169) and commercial (n = 78) beekeepers managed the majority (91.7 \%) of the 414 267 surveyed colonies. Overall, 15.1 \% of the estimated 2.74 million managed colonies in the USA were included in the study. Total honey bee colony losses (based on the entirety of included colonies) were higher in summer (25.3 \%) than in winter (22.3 \%) and amounted to 40.6 \% for the entire 2014/2015 beekeeping year. Average colony losses per beekeeper or operation were higher in winter (43.7 \%) than in summer (14.7 \%) and amounted to 49 \% for the entire 2014/2015 beekeeping year. Due to the dominance of backyard beekeepers among participants, average losses per operation (or unweighted loss) stronger reflected this smaller type of beekeeper. Backyard beekeepers mainly named colony management issues (e.g., starvation, weak colony in the fall) as causes for mortality, while sideline and commercial beekeepers stronger emphasized parasites or factors outside their control (e.g., varroa, nosema, queen failure). The second study took place at reclaimed sand mines. Sand mines represent anthropogenically impacted habitats found worldwide, which bear potential for bee conservation. Although floral resources can be limited at these habitats, vegetation free patches of open sandy soils and embankments may offer good nesting possibilities for sand restricted and other bees. We compared bee communities as found in three reclaimed sand mines and at adjacent roadside meadows in Maryland, USA, over two years. Both sand mines and roadsides hosted diverse bee communities with 111 and 88 bee species, respectively. Bee abundances as well as richness and Shannon diversity of bee species were higher in sand mines than at roadsides and negatively correlated with the percentage of vegetational ground cover. Species composition also differed significantly between habitats. Sand mines hosted a higher proportion of ground nesters, more uncommon and more 'sand loving' bees similar to natural sandy areas of Maryland. Despite the destruction of the original pre-mining habitat, sand mines thus appear to represent a unique habitat for wild bees, particularly when natural vegetation and open sand spots are encouraged. Considering habitat loss, the lack of natural disturbance regimes, and ongoing declines of wild bees, sand mines could add promising opportunities for bee conservation which has hitherto mainly focused on agricultural and urban habitats. The third study was an experimental field study on pollinator friendly plants. Bees rely on the pollen and nectar of plants as their food source. Therefore, pollinator friendly plantings are often used for habitat enhancements in bee conservation. Non-native pollinator friendly plants may aid in bee conservation efforts, but have not been tested and compared with native pollinator friendly plants in a common garden experiment. In this study, we seeded mixes of 20 native and 20 non-native pollinator friendly plants in two separate plots at three sites in Maryland, USA. For two years, we recorded flower visitors to the plants throughout the blooming period and additionally sampled bees with pan traps. A total of 3744 bees (120 species) were sampled in the study. Of these, 1708 bees (72 species) were hand netted directly from flowers for comparisons between native and non-native plants. Depending on the season, bee abundance and species richness was either similar or lower (early season and for richness also late season) at native plots compared to non-native plots. Additionally, the overall bee community composition differed significantly between native and non-native plots. Furthermore, native plants were associated with more specialized plant-bee visitation networks compared to non-native plants. In general, visitation networks were more specialized in the early season than the later seasons. Four species (Bombus impatiens, Halictus poeyi/ligatus, Lasioglossum pilosum, and Xylocopa virginica) out of the five most abundant bee species (also including Apis mellifera) foraged more specialized on native than non-native plants. Our study showed that non-native plants were well accepted by a diverse bee community and had a similar to higher attraction for bees compared to native plants. However, we also demonstrated alterations in foraging behavior, bee community assemblage, and visitation networks. As long as used with caution, non-native plants can be a useful addition to native pollinator friendly plantings. This study gives a first example of a direct comparison between native and non-native pollinator friendly plants.}, subject = {Biene}, language = {en} } @phdthesis{Schneider2020, author = {Schneider, Felicitas Maria Hannelore}, title = {Vergleichende Evaluierung verschiedener Ans{\"a}tze des Memory Enhancement bei neurodegenerativen Prozessen}, doi = {10.25972/OPUS-20756}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207562}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Angesichts des dramatischen, weltweiten Anstiegs der Pr{\"a}valenz von Demenzerkrankungen und der aktuellen, unzureichenden Therapieans{\"a}tze ist die Bereitstellung neuer, wirkungsvoller Behandlungsoptionen von gr{\"o}ßter Bedeutung. Technologische, pharmakologische und verhaltensbasierte Verfahren des Memory Enhancement k{\"o}nnten zur L{\"o}sung dieses Problems beitragen: Hierzu z{\"a}hlt die Stammzelltransplantation, die in mehreren Tierstudien zu einer Verbesserung der Ged{\"a}chtnisfunktion f{\"u}hrte. Zudem wird seit L{\"a}ngerem an einer Impfung gegen die Alzheimer-Krankheit mittels β-Amyloid-Antik{\"o}rpern geforscht. Ein weiterer therapeutischer Ansatz f{\"u}r die Alzheimer-Krankheit besteht in der optogenetischen Stimulation spezifischer hippocampaler Engramm-Zellen, durch die bei einem Maus-Modell verloren gegangene Erinnerungen wiederhergestellt werden konnten. Unkonventionelle Pharmazeutika wie Erythropoetin f{\"u}hrten in Tierstudien und bei Patienten mit neuropsychiatrischen Erkrankungen zu einer Verbesserung der kognitiven F{\"a}higkeiten und des Ged{\"a}chtnisses. Eine Modifikation der Ern{\"a}hrung und der Einsatz von Pro- und Pr{\"a}biotika beeinflussen das Ged{\"a}chtnis {\"u}ber eine Manipulation der Darm-Hirn-Achse. Verhaltensbasierte Maßnahmen wie k{\"o}rperliche Aktivit{\"a}t und der Einsatz von Mnemotechniken stellen effektive Ans{\"a}tze des Memory Enhancement dar, welche bereits heute von gesunden Individuen implementiert werden k{\"o}nnen. F{\"u}r die Anwendung von Augmented Reality (AR) konnten kognitionsf{\"o}rdernde Wirkungen beim Lernen neuroanatomischer Themen und dem Zusammenbau von Objekten nachgewiesen werden. Besonders vielversprechend stellt sich die Entwicklung einer Ged{\"a}chtnisprothese dar, durch die vergessene Informationen bei Personen mit stattgehabtem Sch{\"a}del-Hirn-Trauma und apoplektischem Insult reaktiviert werden k{\"o}nnten. Memory Enhancement ist prinzipiell bereits heute bei gesunden und kranken Individuen anwendbar und verspricht wirksame zuk{\"u}nftige Pr{\"a}ventions- und Therapieoptionen. Ein realer Einsatz in der klinischen Praxis ist in naher Zukunft jedoch noch nicht zu erwarten.}, subject = {Neurodegeneration}, language = {de} } @phdthesis{Goetz2020, author = {G{\"o}tz, Ralph}, title = {Super-resolution microscopy of plasma membrane receptors and intracellular pathogens}, doi = {10.25972/OPUS-20716}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207165}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Humans tend to believe in what they can see with their own eyes. Hence, visualization methods like microscopy have always been extremely popular since their invention in the 17th century. With the advent of super-resolution microscopy, the diffraction limit of ~200 - 250 nm could be overcome to enable more detailed insights into biological samples. Especially the single molecule localization microscopy method dSTORM offers the possibility of quantitative bioimaging. Hereby, the repetitive photoswitching of organic dyes in the presence of thiols is exploited to enable a lateral resolution of 20 nm. Another, recently introduced super-resolution method is expansion microscopy (ExM) which physically expands the sample to increase the resolution by the expansion factor from four to even twenty. To enable this, the sample is embedded into a hydrogel, homogenized using an unspecific proteinase and expanded in distilled water. Within this thesis, both methods were used to shed light on plasma membrane receptor distributions and different bacterial and fungal pathogens. In the first part of this thesis dSTORM was used to elucidate the "Receptome", the entirety of all membrane receptors, of the cell line Jurkat T-cells and primary T-cells. Within this project we could successfully visualize and quantify the distribution of the plasma membrane receptors CD2, CD3, CD4, CD5, CD7, CD11a, CD20, CD28, CD45, CD69 and CD105 with receptor densities ranging from 0.8 cluster/µm² in case of CD20 and 81.4 cluster/µm² for the highly abundant CD45 in activated primary T-cells at the basal membrane. Hereby, we could also demonstrate a homogeneous distribution of most receptors, while only few were clustered. In the case of CD3-clusters were detected in Jurkat T-cells and in primary activated T-cells, but not in na{\"i}ve ones, demonstrating the activation of this receptor. This was followed by the application of dSTORM to three different clinical projects involving the receptors CD38, BCMA and CD20 which are immunotherapeutic targets by monoclonal antibodies and CAR T-cells. In the first two projects dSTORM was applied to determine the receptor upregulation upon exposure of various drugs to MM1.S cells or primary multiple myeloma patient cells. This increase in membrane receptor expression can subsequently enhance the efficacy of therapies directed against these receptors. Within the CD20-project, the superior sensitivity of dSTORM compared to flow cytometry could be demonstrated. Hereby, a substantially higher fraction of CD20-positive patient cells was detected by dSTORM than by flow cytometry. In addition, we could show that by dSTORM CD20-positive evaluated cells were eradicated by immunotherapeutic CAR T-cell treatment. These studies were followed by whole cell super-resolution imaging using both LLS-3D dSTORM and 10x ExM to exclude any artifacts caused by interactions with the glass surface. In 10x ExM signal amplification via biotinylated primary antibodies and streptavidin ATTO 643 was essential to detect even single antibodies directed against the heterodimer CD11a with standard confocal microscopes. Albeit probably not quantitative due to the process of gelation, digestion and expansion during the ExM protocol, even some putative dimers of the receptor CD2 could be visualized using 10x ExM-SIM, similar to dSTORM experiments. Within the second part of this thesis, expansion microscopy was established in bacterial and fungal pathogens. ExM enabled not only an isotropic fourfold expansion of Chlamydia trachomatis, but also allowed the discrimination between the two developmental forms by the chlamydial size after expansion into reticulate and elementary bodies. Hereafter, a new α-NH2-ω-N3-C6-ceramide was introduced enabling an efficient fixation and for the first time the use of lipids in both, 4x and 10x ExM, termed sphingolipid ExM. This compound was used to investigate the ceramide uptake and incorporation into the cell membrane of Chlamydia trachomatis and Simkania negevensis. For Chlamydia trachomatis the combined resolution power of 10x ExM and SIM even allowed the visualization of both bacterial membranes within a distance of ~30 nm. Finally, ExM was applied to the three different fungi Ustilago maydis, Fusarium oxysporum and Aspergillus fumigatus after enzymatic removal of the fungal cell wall. In case of Ustilago maydis sporidia this digestion could be applied to both, living cells resulting in protoplasts and to fixed cells, preserving the fungal morphology. This new protocol could be demonstrated for immunostainings and fluorescent proteins of the three different fungi.}, subject = {Mikroskopie}, language = {en} } @article{GebertSteffanDewenterMorettoetal.2019, author = {Gebert, Friederike and Steffan-Dewenter, Ingolf and Moretto, Philippe and Peters, Marcell K.}, title = {Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro}, series = {Journal of Biogeography}, volume = {47}, journal = {Journal of Biogeography}, number = {2}, doi = {10.1111/jbi.13710}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204701}, pages = {371 -- 381}, year = {2019}, abstract = {Aim: While elevational gradients in species richness constitute some of the best depicted patterns in ecology, there is a large uncertainty concerning the role of food resource availability for the establishment of diversity gradients in insects. Here, we analysed the importance of climate, area, land use and food resources for determining diversity gradients of dung beetles along extensive elevation and land use gradients on Mt. Kilimanjaro, Tanzania. Location: Mt. Kilimanjaro, Tanzania. Taxon: Scarabaeidae (Coleoptera). Methods: Dung beetles were recorded with baited pitfall traps at 66 study plots along a 3.6 km elevational gradient. In order to quantify food resources for the dung beetle community in form of mammal defecation rates, we assessed mammalian diversity and biomass with camera traps. Using a multi-model inference framework and path analysis, we tested the direct and indirect links between climate, area, land use and mammal defecation rates on the species richness and abundance of dung beetles. Results: We found that the species richness of dung beetles declined exponentially with increasing elevation. Human land use diminished the species richness of functional groups exhibiting complex behaviour but did not have a significant influence on total species richness. Path analysis suggested that climate, in particular temperature and to a lesser degree precipitation, were the most important predictors of dung beetle species richness while mammal defecation rate was not supported as a predictor variable. Main conclusions: Along broad climatic gradients, dung beetle diversity is mainly limited by climatic factors rather than by food resources. Our study points to a predominant role of temperature-driven processes for the maintenance and origination of species diversity of ectothermic organisms, which will consequently be subject to ongoing climatic changes.}, language = {en} } @article{HovestadtThomasMitesseretal.2019, author = {Hovestadt, Thomas and Thomas, Jeremy A. and Mitesser, Oliver and Sch{\"o}nrogge, Karsten}, title = {Multiple host use and the dynamics of host-switching in host-parasite systems}, series = {Insect Conservation and Diversity}, volume = {12}, journal = {Insect Conservation and Diversity}, number = {6}, doi = {10.1111/icad.12374}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204747}, pages = {511-522}, year = {2019}, abstract = {The link between multi-host use and host switching in host-parasite interactions is a continuing area of debate. Lycaenid butterflies in the genus Maculinea, for example, exploit societies of different Myrmica ant species across their ranges, but there is only rare evidence that they simultaneously utilise multiple hosts at a local site, even where alternative hosts are present. We present a simple population-genetic model accounting for the proportion of two alternative hosts and the fitness of parasite genotypes on each host. In agreement with standard models, we conclude that simultaneous host use is possible whenever fitness of heterozygotes on alternative hosts is not too low. We specifically focus on host-shifting dynamics when the frequency of hosts changes. We find that (i) host shifting may proceed so rapidly that multiple host use is unlikely to be observed, (ii) back and forth transition in host use can exhibit a hysteresis loop, (iii) the parasites' host use may not be proportional to local host frequencies and be restricted to the rarer host under some conditions, and (iv) that a substantial decline in parasite abundance may typically precede a shift in host use. We conclude that focusing not just on possible equilibrium conditions but also considering the dynamics of host shifting in non-equilibrium situations may provide added insights into host-parasite systems.}, language = {en} } @article{BoetzlKonleKrauss2019, author = {Boetzl, Fabian A. and Konle, Antonia and Krauss, Jochen}, title = {Aphid cards - useful model for assessing predation rates or bias prone nonsense?}, series = {Journal of Applied Entomology}, volume = {144}, journal = {Journal of Applied Entomology}, number = {1-2}, doi = {10.1111/jen.12692}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204798}, pages = {74-80}, year = {2019}, abstract = {Predation on pest organisms is an essential ecosystem function supporting yields in modern agriculture. However, assessing predation rates is intricate, and they can rarely be linked directly to predator densities or functions. We tested whether sentinel prey aphid cards are useful tools to assess predation rates in the field. Therefore, we looked at aphid cards of different sizes on the ground level as well as within the vegetation. Additionally, by trapping ground-dwelling predators, we examined whether obtained predation rates could be linked to predator densities and traits. Predation rates recorded with aphid cards were independent of aphid card size. However, predation rates on the ground level were three times higher than within the vegetation. We found both predatory carabid activity densities as well as community weighted mean body size to be good predictors for predation rates. Predation rates obtained from aphid cards are stable over card type and related to predator assemblages. Aphid cards, therefore, are a useful, efficient method for rapidly assessing the ecosystem function predation. Their use might especially be recommended for assessments on the ground level and when time and resource limitations rule out more elaborate sentinel prey methods using exclosures with living prey animals.}, language = {en} } @article{FigueiredoKraussSteffanDewenteretal.2019, author = {Figueiredo, Ludmilla and Krauss, Jochen and Steffan-Dewenter, Ingolf and Cabral, Juliano Sarmento}, title = {Understanding extinction debts: spatio-temporal scales, mechanisms and a roadmap for future research}, series = {Ecography}, volume = {42}, journal = {Ecography}, number = {12}, doi = {10.1111/ecog.04740}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204859}, pages = {1973-1990}, year = {2019}, abstract = {Extinction debt refers to delayed species extinctions expected as a consequence of ecosystem perturbation. Quantifying such extinctions and investigating long-term consequences of perturbations has proven challenging, because perturbations are not isolated and occur across various spatial and temporal scales, from local habitat losses to global warming. Additionally, the relative importance of eco-evolutionary processes varies across scales, because levels of ecological organization, i.e. individuals, (meta)populations and (meta)communities, respond hierarchically to perturbations. To summarize our current knowledge of the scales and mechanisms influencing extinction debts, we reviewed recent empirical, theoretical and methodological studies addressing either the spatio-temporal scales of extinction debts or the eco-evolutionary mechanisms delaying extinctions. Extinction debts were detected across a range of ecosystems and taxonomic groups, with estimates ranging from 9 to 90\% of current species richness. The duration over which debts have been sustained varies from 5 to 570 yr, and projections of the total period required to settle a debt can extend to 1000 yr. Reported causes of delayed extinctions are 1) life-history traits that prolong individual survival, and 2) population and metapopulation dynamics that maintain populations under deteriorated conditions. Other potential factors that may extend survival time such as microevolutionary dynamics, or delayed extinctions of interaction partners, have rarely been analyzed. Therefore, we propose a roadmap for future research with three key avenues: 1) the microevolutionary dynamics of extinction processes, 2) the disjunctive loss of interacting species and 3) the impact of multiple regimes of perturbation on the payment of debts. For their ability to integrate processes occurring at different levels of ecological organization, we highlight mechanistic simulation models as tools to address these knowledge gaps and to deepen our understanding of extinction dynamics.}, language = {en} } @article{PaulsHamaratTrufasuetal.2019, author = {Pauls, Dennis and Hamarat, Yasmin and Trufasu, Luisa and Schendzielorz, Tim M. and Gramlich, Gertrud and Kahnt, J{\"o}rg and Vanselow, Jens and Schlosser, Andreas and Wegener, Christian}, title = {Drosophila carboxypeptidase D (SILVER) is a key enzyme in neuropeptide processing required to maintain locomotor activity levels and survival rate}, series = {European Journal of Neuroscience}, volume = {50}, journal = {European Journal of Neuroscience}, number = {9}, doi = {10.1111/ejn.14516}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204863}, pages = {3502-3519}, year = {2019}, abstract = {Neuropeptides are processed from larger preproproteins by a dedicated set of enzymes. The molecular and biochemical mechanisms underlying preproprotein processing and the functional importance of processing enzymes are well-characterised in mammals, but little studied outside this group. In contrast to mammals, Drosophila melanogaster lacks a gene for carboxypeptidase E (CPE ), a key enzyme for mammalian peptide processing. By combining peptidomics and neurogenetics, we addressed the role of carboxypeptidase D (dCPD ) in global neuropeptide processing and selected peptide-regulated behaviours in Drosophila . We found that a deficiency in dCPD results in C-terminally extended peptides across the peptidome, suggesting that dCPD took over CPE function in the fruit fly. dCPD is widely expressed throughout the nervous system, including peptidergic neurons in the mushroom body and neuroendocrine cells expressing adipokinetic hormone. Conditional hypomorphic mutation in the dCPD -encoding gene silver in the larva causes lethality, and leads to deficits in starvation-induced hyperactivity and appetitive gustatory preference, as well as to reduced viability and activity levels in adults. A phylogenomic analysis suggests that loss of CPE is not common to insects, but only occurred in Hymenoptera and Diptera. Our results show that dCPD is a key enzyme for neuropeptide processing and peptide-regulated behaviour in Drosophila . dCPD thus appears as a suitable target to genetically shut down total neuropeptide production in peptidergic neurons. The persistent occurrence of CPD in insect genomes may point to important further CPD functions beyond neuropeptide processing which cannot be fulfilled by CPE.}, language = {en} } @article{ZielewskaBuettnerHeurichMuelleretal.2018, author = {Zielewska-B{\"u}ttner, Katarzyna and Heurich, Marco and M{\"u}ller, J{\"o}rg and Braunisch, Veronika}, title = {Remotely Sensed Single Tree Data Enable the Determination of Habitat Thresholds for the Three-Toed Woodpecker (Picoides tridactylus)}, series = {Remote Sensing}, volume = {10}, journal = {Remote Sensing}, number = {12}, issn = {2072-4292}, doi = {10.3390/rs10121972}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197565}, year = {2018}, abstract = {Forest biodiversity conservation requires precise, area-wide information on the abundance and distribution of key habitat structures at multiple spatial scales. We combined airborne laser scanning (ALS) data with color-infrared (CIR) aerial imagery for identifying individual tree characteristics and quantifying multi-scale habitat requirements using the example of the three-toed woodpecker (Picoides tridactylus) (TTW) in the Bavarian Forest National Park (Germany). This bird, a keystone species of boreal and mountainous forests, is highly reliant on bark beetles dwelling in dead or dying trees. While previous studies showed a positive relationship between the TTW presence and the amount of deadwood as a limiting resource, we hypothesized a unimodal response with a negative effect of very high deadwood amounts and tested for effects of substrate quality. Based on 104 woodpecker presence or absence locations, habitat selection was modelled at four spatial scales reflecting different woodpecker home range sizes. The abundance of standing dead trees was the most important predictor, with an increase in the probability of TTW occurrence up to a threshold of 44-50 dead trees per hectare, followed by a decrease in the probability of occurrence. A positive relationship with the deadwood crown size indicated the importance of fresh deadwood. Remote sensing data allowed both an area-wide prediction of species occurrence and the derivation of ecological threshold values for deadwood quality and quantity for more informed conservation management.}, language = {en} } @article{BeerSteffanDewenterHaerteletal.2016, author = {Beer, Katharina and Steffan-Dewenter, Ingolf and H{\"a}rtel, Stephan and Helfrich-F{\"o}rster, Charlotte}, title = {A new device for monitoring individual activity rhythms of honey bees reveals critical effects of the social environment on behavior}, series = {Journal of Comparative Physiology A}, volume = {202}, journal = {Journal of Comparative Physiology A}, number = {8}, doi = {10.1007/s00359-016-1103-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188030}, pages = {555-565}, year = {2016}, abstract = {Chronobiological studies of individual activity rhythms in social insects can be constrained by the artificial isolation of individuals from their social context. We present a new experimental set-up that simultaneously measures the temperature rhythm in a queen-less but brood raising mini colony and the walking activity rhythms of singly kept honey bees that have indirect social contact with it. Our approach enables monitoring of individual bees in the social context of a mini colony under controlled laboratory conditions. In a pilot experiment, we show that social contact with the mini colony improves the survival of monitored young individuals and affects locomotor activity patterns of young and old bees. When exposed to conflicting Zeitgebers consisting of a light-dark (LD) cycle that is phase-delayed with respect to the mini colony rhythm, rhythms of young and old bees are socially synchronized with the mini colony rhythm, whereas isolated bees synchronize to the LD cycle. We conclude that the social environment is a stronger Zeitgeber than the LD cycle and that our new experimental set-up is well suited for studying the mechanisms of social entrainment in honey bees.}, language = {en} } @article{YadavSelvarajBenderetal.2016, author = {Yadav, Preeti and Selvaraj, Bhuvaneish T. and Bender, Florian L. P. and Behringer, Marcus and Moradi, Mehri and Sivadasan, Rajeeve and Dombert, Benjamin and Blum, Robert and Asan, Esther and Sauer, Markus and Julien, Jean-Pierre and Sendtner, Michael}, title = {Neurofilament depletion improves microtubule dynamics via modulation of Stat3/stathmin signaling}, series = {Acta Neuropathologica}, volume = {132}, journal = {Acta Neuropathologica}, number = {1}, doi = {10.1007/s00401-016-1564-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188234}, pages = {93-110}, year = {2016}, abstract = {In neurons, microtubules form a dense array within axons, and the stability and function of this microtubule network is modulated by neurofilaments. Accumulation of neurofilaments has been observed in several forms of neurodegenerative diseases, but the mechanisms how elevated neurofilament levels destabilize axons are unknown so far. Here, we show that increased neurofilament expression in motor nerves of pmn mutant mice, a model of motoneuron disease, causes disturbed microtubule dynamics. The disease is caused by a point mutation in the tubulin-specific chaperone E (Tbce) gene, leading to an exchange of the most C-terminal amino acid tryptophan to glycine. As a consequence, the TBCE protein becomes instable which then results in destabilization of axonal microtubules and defects in axonal transport, in particular in motoneurons. Depletion of neurofilament increases the number and regrowth of microtubules in pmn mutant motoneurons and restores axon elongation. This effect is mediated by interaction of neurofilament with the stathmin complex. Accumulating neurofilaments associate with stathmin in axons of pmn mutant motoneurons. Depletion of neurofilament by Nefl knockout increases Stat3-stathmin interaction and stabilizes the microtubules in pmn mutant motoneurons. Consequently, counteracting enhanced neurofilament expression improves axonal maintenance and prolongs survival of pmn mutant mice. We propose that this mechanism could also be relevant for other neurodegenerative diseases in which neurofilament accumulation and loss of microtubules are prominent features.}, language = {en} } @article{BemmBeckerLarischetal.2016, author = {Bemm, Felix and Becker, Dirk and Larisch, Christina and Kreuzer, Ines and Escalante-Perez, Maria and Schulze, Waltraud X. and Ankenbrand, Markus and Van de Weyer, Anna-Lena and Krol, Elzbieta and Al-Rasheid, Khaled A. and Mith{\"o}fer, Axel and Weber, Andreas P. and Schultz, J{\"o}rg and Hedrich, Rainer}, title = {Venus flytrap carnivorous lifestyle builds on herbivore defense strategies}, series = {Genome Research}, volume = {26}, journal = {Genome Research}, number = {6}, doi = {10.1101/gr.202200.115}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188799}, pages = {812-825}, year = {2016}, abstract = {Although the concept of botanical carnivory has been known since Darwin's time, the molecular mechanisms that allow animal feeding remain unknown, primarily due to a complete lack of genomic information. Here, we show that the transcriptomic landscape of the Dionaea trap is dramatically shifted toward signal transduction and nutrient transport upon insect feeding, with touch hormone signaling and protein secretion prevailing. At the same time, a massive induction of general defense responses is accompanied by the repression of cell death-related genes/processes. We hypothesize that the carnivory syndrome of Dionaea evolved by exaptation of ancient defense pathways, replacing cell death with nutrient acquisition.}, language = {en} } @article{KupperStigloherFeldhaaretal.2016, author = {Kupper, Maria and Stigloher, Christian and Feldhaar, Heike and Gross, Roy}, title = {Distribution of the obligate endosymbiont Blochmannia floridanus and expression analysis of putative immune genes in ovaries of the carpenter ant Camponotus floridanus}, series = {Arthropod Structure \& Development}, volume = {45}, journal = {Arthropod Structure \& Development}, number = {5}, doi = {10.1016/j.asd.2016.09.004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187482}, pages = {475-487}, year = {2016}, abstract = {The bacterial endosymbiont Blochmannia floridanus of the carpenter ant Camponotus floridanus contributes to its hosts' ontogeny via nutritional upgrading during metamorphosis. This primary endosymbiosis is essential for both partners and vertical transmission of the endosymbionts is guaranteed by bacterial infestation of oocytes. Here we present a detailed analysis of the presence and localisation of B. floridanus in the ants' ovaries obtained by FISH and TEM analyses. The most apical part of the germarium harbouring germ-line stem cells (GSCs) is not infected by the bacteria. The bacteria are detectable for the first time in lower parts of the germarium when cystocytes undergo the 4th and 5th division and B. floridanus infects somatic cells lying under the basal lamina surrounding the ovarioles. With the beginning of cystocyte differentiation, the endosymbionts are exclusively transported from follicle cells into the growing oocytes. This infestation of the oocytes by bacteria very likely involves exocytosis endocytosis processes between follicle cells and the oocytes. Nurse cells were never found to harbour the endosymbionts. Furthermore we present first gene expression data in C floridanus ovaries. These data indicate a modulation of immune gene expression which may facilitate tolerance towards the endosymbionts and thus may contribute to their transovarial transmission.}, language = {en} } @article{ChagtaiZillDaineseetal.2016, author = {Chagtai, Tasnim and Zill, Christina and Dainese, Linda and Wegert, Jenny and Savola, Suvi and Popov, Sergey and Mifsud, William and Vujanic, Gordan and Sebire, Neil and Le Bouc, Yves and Ambros, Peter F. and Kager, Leo and O`Sullivan, Maureen J. and Blaise, Annick and Bergeron, Christophe and Holmquist Mengelbier, Linda and Gisselsson, David and Kool, Marcel and Tytgat, Godelieve A.M. and van den Heuvel-Eibrink, Marry M. and Graf, Norbert and van Tinteren, Harm and Coulomb, Aurore and Gessler, Manfred and Williams, Richard Dafydd and Pritchard-Jones, Kathy}, title = {Gain of 1q As a Prognostic Biomarker in Wilms Tumors (WTs) Treated With Preoperative Chemotherapy in the International Society of Paediatric Oncology (SIOP) WT 2001 Trial: a SIOP Renal Tumours Biology Consortium Study}, series = {Journal of Clinical Oncology}, volume = {34}, journal = {Journal of Clinical Oncology}, number = {26}, doi = {10.1200/JCO.2015.66.0001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187478}, pages = {3195-3205}, year = {2016}, abstract = {Purpose Wilms tumor (WT) is the most common pediatric renal tumor. Treatment planning under International Society of Paediatric Oncology (SIOP) protocols is based on staging and histologic assessment of response to preoperative chemotherapy. Despite high overall survival (OS), many relapses occur in patients without specific risk factors, and many successfully treated patients are exposed to treatments with significant risks of late effects. To investigate whether molecular biomarkers could improve risk stratification, we assessed 1q status and other potential copy number biomarkers in a large WT series. Materials and Methods WT nephrectomy samples from 586 SIOP WT 2001 patients were analyzed using a multiplex ligation-dependent probe amplification (MLPA) assay that measured the copy number of 1q and other regions of interest. Results One hundred sixty-seven (28\%) of 586 WTs had 1q gain. Five-year event-free survival (EFS) was 75.0\% in patients with 1q gain (95\% CI, 68.5\% to 82.0\%) and 88.2\% in patients without gain (95\% CI, 85.0\% to 91.4\%). OS was 88.4\% with gain (95\% CI, 83.5\% to 93.6\%) and 94.4\% without gain (95\% CI, 92.1\% to 96.7\%). In univariable analysis, 1q gain was associated with poorer EFS (P<.001; hazard ratio, 2.33) and OS (P=.01; hazard ratio, 2.16). The association of 1q gain with poorer EFS retained significance in multivariable analysis adjusted for 1p and 16q loss, sex, stage, age, and histologic risk group. Gain of 1q remained associated with poorer EFS in tumor subsets limited to either intermediate-risk localized disease or nonanaplastic localized disease. Other notable aberrations associated with poorer EFS included MYCN gain and TP53 loss. Conclusion Gain of 1q is a potentially valuable prognostic biomarker in WT, in addition to histologic response to preoperative chemotherapy and tumor stage.}, language = {en} } @article{HolzschuhDaineseGonzalezVaroetal.2016, author = {Holzschuh, Andrea and Dainese, Matteo and Gonzalez-Varo, Juan P. and Mudri-Stojnic, Sonja and Riedinger, Verena and Rundl{\"o}f, Maj and Scheper, Jeroen and Wickens, Jennifer B. and Wickens, Victoria J. and Bommarco, Riccardo and Kleijn, David and Potts, Simon G. and Roberts, Stuart P. M. and Smith, Henrik G. and Vil{\`a}, Montserrat and Vujic, Ante and Steffan-Dewenter, Ingolf}, title = {Mass-flowering crops dilute pollinator abundance in agricultural landscapes across Europe}, series = {Ecology Letters}, volume = {19}, journal = {Ecology Letters}, number = {10}, doi = {10.1111/ele.12657}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187356}, pages = {1228-1236}, year = {2016}, abstract = {Mass-flowering crops (MFCs) are increasingly cultivated and might influence pollinator communities in MFC fields and nearby semi-natural habitats (SNHs). Across six European regions and 2 years, we assessed how landscape-scale cover of MFCs affected pollinator densities in 408 MFC fields and adjacent SNHs. In MFC fields, densities of bumblebees, solitary bees, managed honeybees and hoverflies were negatively related to the cover of MFCs in the landscape. In SNHs, densities of bumblebees declined with increasing cover of MFCs but densities of honeybees increased. The densities of all pollinators were generally unrelated to the cover of SNHs in the landscape. Although MFC fields apparently attracted pollinators from SNHs, in landscapes with large areas of MFCs they became diluted. The resulting lower densities might negatively affect yields of pollinator- dependent crops and the reproductive success of wild plants. An expansion of MFCs needs to be accompanied by pollinator-supporting practices in agricultural landscapes.}, language = {en} } @article{MarkertBritzProppertetal.2016, author = {Markert, Sebastian Matthias and Britz, Sebastian and Proppert, Sven and Lang, Marietta and Witvliet, Daniel and Mulcahy, Ben and Sauer, Markus and Zhen, Mei and Bessereau, Jean-Louis and Stigloher, Christian}, title = {Filling the gap: adding super-resolution to array tomography for correlated ultrastructural and molecular identification of electrical synapses at the C. elegans connectome}, series = {Neurophotonics}, volume = {3}, journal = {Neurophotonics}, number = {4}, doi = {10.1117/1.NPh.3.4.041802}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187292}, pages = {041802}, year = {2016}, abstract = {Correlating molecular labeling at the ultrastructural level with high confidence remains challenging. Array tomography (AT) allows for a combination of fluorescence and electron microscopy (EM) to visualize subcellular protein localization on serial EM sections. Here, we describe an application for AT that combines near-native tissue preservation via high-pressure freezing and freeze substitution with super-resolution light microscopy and high-resolution scanning electron microscopy (SEM) analysis on the same section. We established protocols that combine SEM with structured illumination microscopy (SIM) and direct stochastic optical reconstruction microscopy (dSTORM). We devised a method for easy, precise, and unbiased correlation of EM images and super-resolution imaging data using endogenous cellular landmarks and freely available image processing software. We demonstrate that these methods allow us to identify and label gap junctions in Caenorhabditis elegans with precision and confidence, and imaging of even smaller structures is feasible. With the emergence of connectomics, these methods will allow us to fill in the gap-acquiring the correlated ultrastructural and molecular identity of electrical synapses.}, language = {en} } @article{ScharawIskarOrietal.2016, author = {Scharaw, Sandra and Iskar, Murat and Ori, Alessandro and Boncompain, Gaelle and Laketa, Vibor and Poser, Ina and Lundberg, Emma and Perez, Franck and Beck, Martin and Bork, Peer and Pepperkok, Rainer}, title = {The endosomal transcriptional regulator RNF11 integrates degradation and transport of EGFR}, series = {Journal of Cell Biology}, volume = {215}, journal = {Journal of Cell Biology}, number = {4}, doi = {10.1083/jcb.201601090}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186731}, pages = {543-558}, year = {2016}, abstract = {Stimulation of cells with epidermal growth factor (EGF) induces internalization and partial degradation of the EGF receptor (EGFR) by the endo-lysosomal pathway. For continuous cell functioning, EGFR plasma membrane levels are maintained by transporting newly synthesized EGFRs to the cell surface. The regulation of this process is largely unknown. In this study, we find that EGF stimulation specifically increases the transport efficiency of newly synthesized EGFRs from the endoplasmic reticulum to the plasma membrane. This coincides with an up-regulation of the inner coat protein complex II (COP II) components SEC23B, SEC24B, and SEC24D, which we show to be specifically required for EGFR transport. Up-regulation of these COP II components requires the transcriptional regulator RNF11, which localizes to early endosomes and appears additionally in the cell nucleus upon continuous EGF stimulation. Collectively, our work identifies a new regulatory mechanism that integrates the degradation and transport of EGFR in order to maintain its physiological levels at the plasma membrane.}, language = {en} } @article{BertChmielewskaBergmannetal.2016, author = {Bert, Bettina and Chmielewska, Justyna and Bergmann, Sven and Busch, Maximilian and Driever, Wolfgang and Finger-Baier, Karin and H{\"o}ßler, Johanna and K{\"o}hler, Almut and Leich, Nora and Misgeld, Thomas and N{\"o}ldner, Torsten and Reiher, Annegret and Schartl, Manfred and Seebach-Sproedt, Anja and Thumberger, Thomas and Sch{\"o}nfelder, Gilbert and Grune, Barbara}, title = {Considerations for a European animal welfare standard to evaluate adverse phenotypes in teleost fish}, series = {The EMBO Journal}, volume = {35}, journal = {The EMBO Journal}, number = {11}, doi = {10.15252/embj.201694448}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188783}, pages = {1151-1154}, year = {2016}, abstract = {No abstract available.}, language = {en} } @article{SchneiderDittrichBoecketal.2016, author = {Schneider, Eberhard and Dittrich, Marcus and B{\"o}ck, Julia and Nanda, Indrajit and M{\"u}ller, Tobias and Seidmann, Larissa and Tralau, Tim and Galetzka, Danuta and El Hajj, Nady and Haaf, Thomas}, title = {CpG sites with continuously increasing or decreasing methylation from early to late human fetal brain development}, series = {Gene}, volume = {592}, journal = {Gene}, number = {1}, doi = {10.1016/j.gene.2016.07.058}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186936}, pages = {110-118}, year = {2016}, abstract = {Normal human brain development is dependent on highly dynamic epigenetic processes for spatial and temporal gene regulation. Recent work identified wide-spread changes in DNA methylation during fetal brain development. We profiled CpG methylation in frontal cortex of 27 fetuses from gestational weeks 12-42, using Illumina 450K methylation arrays. Sites showing genome-wide significant correlation with gestational age were compared to a publicly available data set from gestational weeks 3-26. Altogether, we identified 2016 matching developmentally regulated differentially methylated positions (m-dDMPs): 1767 m-dDMPs were hypermethylated and 1149 hypomethylated during fetal development. M-dDMPs are underrepresented in CpG islands and gene promoters, and enriched in gene bodies. They appear to cluster in certain chromosome regions. M-dDMPs are significantly enriched in autism-associated genes and CpGs. Our results promote the idea that reduced methylation dynamics during fetal brain development may predispose to autism. In addition, m-dDMPs are enriched in genes with human-specific brain expression patterns and/or histone modifications. Collectively, we defined a subset of dDMPs exhibiting constant methylation changes from early to late pregnancy. The same epigenetic mechanisms involving methylation changes in cis-regulatory regions may have been adopted for human brain evolution and ontogeny.}, language = {en} } @article{DotterweichSchlegelmilchKelleretal.2016, author = {Dotterweich, Julia and Schlegelmilch, Katrin and Keller, Alexander and Geyer, Beate and Schneider, Doris and Zeck, Sabine and Tower, Robert J. J. and Ebert, Regina and Jakob, Franz and Sch{\"u}tze, Norbert}, title = {Contact of myeloma cells induces a characteristic transcriptome signature in skeletal precursor cells-implications for myeloma bone disease}, series = {Bone}, volume = {93}, journal = {Bone}, doi = {10.1016/j.bone.2016.08.006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186688}, pages = {155-166}, year = {2016}, abstract = {Physical interaction of skeletal precursors with multiple myeloma cells has been shown to suppress their osteogenic potential while favoring their tumor-promoting features. Although several transcriptome analyses of myeloma patient-derived mesenchymal stem cells have displayed differences compared to their healthy counterparts, these analyses insufficiently reflect the signatures mediated by tumor cell contact, vary due to different methodologies, and lack results in lineage-committed precursors. To determine tumor cell contact-mediated changes on skeletal precursors, we performed transcriptome analyses of mesenchymal stem cells and osteogenic precursor cells cultured in contact with the myeloma cell line INA-6. Comparative analyses confirmed dysregulation of genes which code for known disease-relevant factors and additionally revealed upregulation of genes that are associated with plasma cell homing, adhesion, osteoclastogenesis, and angiogenesis. Osteoclast-derived coupling factors, a dysregulated adipogenic potential, and an imbalance in favor of anti-anabolic factors may play a role in the hampered osteoblast differentiation potential of mesenchymal stem cells. Angiopoietin-Like 4 (ANGPTL4) was selected from a list of differentially expressed genes as a myeloma cell contact-dependent target in skeletal precursor cells which warranted further functional analyses. Adhesion assays with full-length ANGPTL4-coated plates revealed a potential role of this protein in INA6 cell attachment. This study expands knowledge of the myeloma cell contact-induced signature in the stromal compartment of myelomatous bones and thus offers potential targets that may allow detection and treatment of myeloma bone disease at an early stage.}, language = {en} } @article{HassounaOttWuestefeldetal.2016, author = {Hassouna, I. and Ott, C. and W{\"u}stefeld, L. and Offen, N. and Neher, R. A. and Mitkovski, M. and Winkler, D. and Sperling, S. and Fries, L. and Goebbels, S. and Vreja, I. C. and Hagemeyer, N. and Dittrich, M. and Rossetti, M. F. and Kr{\"o}hnert, K. and Hannke, K. and Boretius, S. and Zeug, A. and H{\"o}schen, C. and Dandekar, T. and Dere, E. and Neher, E. and Rizzoli, S. O. and Nave, K.-A. and Sir{\´e}n, A.-L. and Ehrenreich, H.}, title = {Revisiting adult neurogenesis and the role of erythropoietin for neuronal and oligodendroglial differentiation in the hippocampus}, series = {Molecular Psychiatry}, volume = {21}, journal = {Molecular Psychiatry}, number = {12}, doi = {10.1038/mp.2015.212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186669}, pages = {1752-1767}, year = {2016}, abstract = {Recombinant human erythropoietin (EPO) improves cognitive performance in neuropsychiatric diseases ranging from schizophrenia and multiple sclerosis to major depression and bipolar disease. This consistent EPO effect on cognition is independent of its role in hematopoiesis. The cellular mechanisms of action in brain, however, have remained unclear. Here we studied healthy young mice and observed that 3-week EPO administration was associated with an increased number of pyramidal neurons and oligodendrocytes in the hippocampus of similar to 20\%. Under constant cognitive challenge, neuron numbers remained elevated until >6 months of age. Surprisingly, this increase occurred in absence of altered cell proliferation or apoptosis. After feeding a \(^{15}\)N-leucine diet, we used nanoscopic secondary ion mass spectrometry, and found that in EPO-treated mice, an equivalent number of neurons was defined by elevated \(^{15}\)N-leucine incorporation. In EPO-treated NG2-Cre-ERT2 mice, we confirmed enhanced differentiation of preexisting oligodendrocyte precursors in the absence of elevated DNA synthesis. A corresponding analysis of the neuronal lineage awaits the identification of suitable neuronal markers. In cultured neurospheres, EPO reduced Sox9 and stimulated miR124, associated with advanced neuronal differentiation. We are discussing a resulting working model in which EPO drives the differentiation of non-dividing precursors in both (NG2+) oligodendroglial and neuronal lineages. As endogenous EPO expression is induced by brain injury, such a mechanism of adult neurogenesis may be relevant for central nervous system regeneration.}, language = {en} } @article{VazeHelfrichFoerster2016, author = {Vaze, Koustubh M. and Helfrich-F{\"o}rster, Charlotte}, title = {Drosophila ezoana uses an hour-glass or highly damped circadian clock for measuring night length and inducing diapause}, series = {Physiological Entomology}, volume = {41}, journal = {Physiological Entomology}, number = {4}, doi = {10.1111/phen.12165}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204278}, pages = {378-389}, year = {2016}, abstract = {Insects inhabiting the temperate zones measure seasonal changes in day or night length to enter the overwintering diapause. Diapause induction occurs after the duration of the night exceeds a critical night length (CNL). Our understanding of the time measurement mechanisms is continuously evolving subsequent to B{\"u}nning's proposal that circadian systems play the clock role in photoperiodic time measurement (B{\"u}nning, 1936). Initially, the photoperiodic clocks were considered to be either based on circadian oscillators or on simple hour-glasses, depending on 'positive' or 'negative' responses in Nanda-Hamner and B{\"u}nsow experiments (Nanda \& Hammer, 1958; B{\"u}nsow, 1960). However, there are also species whose responses can be regarded as neither 'positive', nor as 'negative', such as the Northern Drosophila species Drosophila ezoana, which is investigated in the present study. In addition, modelling efforts show that the 'positive' and 'negative' Nanda-Hamner responses can also be provoked by circadian oscillators that are damped to different degrees: animals with highly sustained circadian clocks will respond 'positive' and those with heavily damped circadian clocks will respond 'negative'. In the present study, an experimental assay is proposed that characterizes the photoperiodic oscillators by determining the effects of non-24-h light/dark cycles (T-cycles) on critical night length. It is predicted that there is (i) a change in the critical night length as a function of T-cycle period in sustained-oscillator-based clocks and (ii) a fxed night-length measurement (i.e. no change in critical night length) in damped-oscillator-based clocks. Drosophila ezoana flies show a critical night length of approximately 7 h irrespective of T-cycle period, suggesting a damped-oscillator-based photoperiodic clock. The conclusion is strengthened by activity recordings revealing that the activity rhythm of D. ezoana flies also dampens in constant darkness.}, language = {en} } @article{RequierPailletLarocheetal.2019, author = {Requier, Fabrice and Paillet, Yoan and Laroche, Fabienne and Rutschmann, Benjamin and Zhang, Jie and Lombardi, Fabio and Svoboda, Miroslav and Steffan-Dewenter, Ingolf}, title = {Contribution of European forests to safeguard wild honeybee populations}, series = {Conservation Letters}, volume = {13}, journal = {Conservation Letters}, number = {2}, doi = {10.1111/conl.12693}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204407}, pages = {e12693}, year = {2019}, abstract = {Abstract Recent studies reveal the use of tree cavities by wild honeybee colonies in European forests. This highlights the conservation potential of forests for a highly threatened component of the native entomofauna in Europe, but currently no estimate of potential wild honeybee population sizes exists. Here, we analyzed the tree cavity densities of 106 forest areas across Europe and inferred an expected population size of wild honeybees. Both forest and management types affected the density of tree cavities. Accordingly, we estimated that more than 80,000 wild honeybee colonies could be sustained in European forests. As expected, potential conservation hotspots were identified in unmanaged forests, and, surprisingly, also in other large forest areas across Europe. Our results contribute to the EU policy strategy to halt pollinator declines and reveal the potential of forest areas for the conservation of so far neglected wild honeybee populations in Europe.}, language = {en} } @article{DiersWagnerBaumetal.2019, author = {Diers, J. and Wagner, J. and Baum, P. and Lichthardt, S. and Kastner, C. and Matthes, N. and L{\"o}b, S. and Matthes, H. and Germer, C.-T. and Wiegering, A.}, title = {Nationwide in-hospital mortality following colonic cancer resection according to hospital volume in Germany}, series = {BJS Open}, volume = {3}, journal = {BJS Open}, number = {5}, doi = {10.1002/bjs5.50173}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204385}, pages = {672-677}, year = {2019}, abstract = {Background: Colonic cancer is the most common cancer of the gastrointestinal tract. The aim of this study was to determine mortality rates following colonic cancer resection and the effect of hospital caseload on in-hospital mortality in Germany. Methods: Patients admitted with a diagnosis of colonic cancer undergoing colonic resection from 2012 to 2015 were identifed from a nationwide registry using procedure codes. The outcome measure was in-hospital mortality. Hospitals were ranked according to their caseload for colonic cancer resection, and patients were categorized into five subgroups on the basis of hospital volume. Results: Some 129 196 colonic cancer resections were reviewed. The overall in-house mortality rate was 5⋅8 per cent, ranging from 6⋅9 per cent (1775 of 25 657 patients) in very low-volume hospitals to 4⋅8 per cent (1239 of 25 825) in very high-volume centres (P < 0⋅001). In multivariable logistic regression analysis the risk-adjusted odds ratio for in-house mortality was 0⋅75 (95 per cent c.i. 0⋅66 to 0⋅84) in very high-volume hospitals performing a mean of 85⋅0 interventions per year, compared with that in very low-volume hospitals performing a mean of only 12⋅7 interventions annually, after adjustment for sex, age, co-morbidity, emergency procedures, prolonged mechanical ventilation and transfusion. Conclusion: In Germany, patients undergoing colonic cancer resections in high-volume hospitals had with improved outcomes compared with patients treated in low-volume hospitals}, language = {en} } @phdthesis{Thelen2020, author = {Thelen, David}, title = {Erstellung eines genregulatorischen Netzwerkes zur Simulation der Entstehung von Zahnhartsubstanz}, doi = {10.25972/OPUS-20406}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204068}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {In this dissertation, the author describes the creation of a basic bioinformatic model of human enamel maturation. Supported by the interactions found in the KEGG Pathway database, we were able to establish a gene regulatory network (GRN) that focuses primarily on the signal transduction pathways apoptosis, cell cycle, hedgehog signaling pathway, MAP kinase pathway, mTOR signaling pathway, Notch signaling pathway, TGF-β signaling pathway and Wnt signaling pathway. We extended this through further verified interactions and implicated the tooth-specific genes AMELX, AMELY, AMBN, ENAM and DSPP. In the subsequent simulation of the network by the simulation tool Jimena, six stable states could be identified. These are examined in more detail and juxtaposed with results of a GEO dataset. The long-term goal is to draw conclusions about the odontogenesis of humans through consistent optimization of the bioinformatics network.}, subject = {Universit{\"a}t W{\"u}rzburg. Lehrstuhl f{\"u}r Bioinformatik}, language = {de} } @article{DuquePoelmanSteffanDewenter2019, author = {Duque, Laura and Poelman, Erik H. and Steffan-Dewenter, Ingolf}, title = {Plant-mediated effects of ozone on herbivores depend on exposure duration and temperature}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-56234-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202805}, pages = {19891}, year = {2019}, abstract = {Abiotic stress by elevated tropospheric ozone and temperature can alter plants' metabolism, growth, and nutritional value and modify the life cycle of their herbivores. We investigated how the duration of exposure of Sinapis arvensis plants to high ozone and temperature levels affect the life cycle of the large cabbage white, Pieris brassicae. Plants were exposed to ozone-clean (control) or ozone-enriched conditions (120 ppb) for either 1 or 5 days and were afterwards kept in a greenhouse with variable temperature conditions. When given the choice, P. brassicae butterflies laid 49\% fewer eggs on ozone-exposed than on control plants when the exposure lasted for 5 days, but showed no preference when exposure lasted for 1 day. The caterpillars took longer to hatch on ozone-exposed plants and at lower ambient temperatures. The ozone treatment had a positive effect on the survival of the eggs. Ozone decreased the growth of caterpillars reared at higher temperatures on plants exposed for 5 days, but not on plants exposed for 1 day. Overall, longer exposure of the plants to ozone and higher temperatures affected the life cycle of the herbivore more strongly. With global warming, the indirect impacts of ozone on herbivores are likely to become more common.}, language = {en} } @article{MaierhoferFlunkertOshimaetal.2019, author = {Maierhofer, Anna and Flunkert, Julia and Oshima, Junko and Martin, George M. and Poot, Martin and Nanda, Indrajit and Dittrich, Marcus and M{\"u}ller, Tobias and Haaf, Thomas}, title = {Epigenetic signatures of Werner syndrome occur early in life and are distinct from normal epigenetic aging processes}, series = {Aging Cell}, volume = {18}, journal = {Aging Cell}, doi = {10.1111/acel.12995}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202733}, pages = {e12995}, year = {2019}, abstract = {Werner Syndrome (WS) is an adult-onset segmental progeroid syndrome. Bisulfite pyrosequencing of repetitive DNA families revealed comparable blood DNA methylation levels between classical (18 WRN-mutant) or atypical WS (3 LMNA-mutant and 3 POLD1-mutant) patients and age- and sex-matched controls. WS was not associated with either age-related accelerated global losses of ALU, LINE1, and α-satellite DNA methylations or gains of rDNA methylation. Single CpG methylation was analyzed with Infinium MethylationEPIC arrays. In a correspondence analysis, atypical WS samples clustered together with the controls and were clearly separated from classical WS, consistent with distinct epigenetic pathologies. In classical WS, we identified 659 differentially methylated regions (DMRs) comprising 3,656 CpG sites and 613 RefSeq genes. The top DMR was located in the HOXA4 promoter. Additional DMR genes included LMNA, POLD1, and 132 genes which have been reported to be differentially expressed in WRN-mutant/depleted cells. DMRs were enriched in genes with molecular functions linked to transcription factor activity and sequence-specific DNA binding to promoters transcribed by RNA polymerase II. We propose that transcriptional misregulation of downstream genes by the absence of WRN protein contributes to the variable premature aging phenotypes of WS. There were no CpG sites showing significant differences in DNA methylation changes with age between WS patients and controls. Genes with both WS- and age-related methylation changes exhibited a constant offset of methylation between WRN-mutant patients and controls across the entire analyzed age range. WS-specific epigenetic signatures occur early in life and do not simply reflect an acceleration of normal epigenetic aging processes.}, language = {en} } @article{BeerSchenkHelfrichFoersteretal.2019, author = {Beer, Katharina and Schenk, Mariela and Helfrich-F{\"o}rster, Charlotte and Holzschuh, Andrea}, title = {The circadian clock uses different environmental time cues to synchronize emergence and locomotion of the solitary bee Osmia bicornis}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-54111-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202721}, pages = {17748}, year = {2019}, abstract = {Life on earth adapted to the daily reoccurring changes in environment by evolving an endogenous circadian clock. Although the circadian clock has a crucial impact on survival and behavior of solitary bees, many aspects of solitary bee clock mechanisms remain unknown. Our study is the first to show that the circadian clock governs emergence in Osmia bicornis, a bee species which overwinters as adult inside its cocoon. Therefore, its eclosion from the pupal case is separated by an interjacent diapause from its emergence in spring. We show that this bee species synchronizes its emergence to the morning. The daily rhythms of emergence are triggered by temperature cycles but not by light cycles. In contrast to this, the bee's daily rhythms in locomotion are synchronized by light cycles. Thus, we show that the circadian clock of O. bicornis is set by either temperature or light, depending on what activity is timed. Light is a valuable cue for setting the circadian clock when bees have left the nest. However, for pre-emerged bees, temperature is the most important cue, which may represent an evolutionary adaptation of the circadian system to the cavity-nesting life style of O. bicornis.}, language = {en} } @article{WagnerKunzChowdhuryetal.2019, author = {Wagner, Fabienne and Kunz, Tobias C. and Chowdhury, Suvagata R. and Thiede, Bernd and Fraunholz, Martin and Eger, Debora and Kozjak-Pavlovic, Vera}, title = {Armadillo repeat-containing protein 1 is a dual localization protein associated with mitochondrial intermembrane space bridging complex}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0218303}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202670}, pages = {e0218303}, year = {2019}, abstract = {Cristae architecture is important for the function of mitochondria, the organelles that play the central role in many cellular processes. The mitochondrial contact site and cristae organizing system (MICOS) together with the sorting and assembly machinery (SAM) forms the mitochondrial intermembrane space bridging complex (MIB), a large protein complex present in mammalian mitochondria that partakes in the formation and maintenance of cristae. We report here a new subunit of the mammalian MICOS/MIB complex, an armadillo repeat-containing protein 1 (ArmC1). ArmC1 localizes both to cytosol and mitochondria, where it associates with the outer mitochondrial membrane through its carboxy-terminus. ArmC1 interacts with other constituents of the MICOS/MIB complex and its amounts are reduced upon MICOS/MIB complex depletion. Mitochondria lacking ArmC1 do not show defects in cristae structure, respiration or protein content, but appear fragmented and with reduced motility. ArmC1 represents therefore a peripheral MICOS/MIB component that appears to play a role in mitochondrial distribution in the cell.}, language = {en} } @article{AkhoonGuptaTiwarietal.2019, author = {Akhoon, Bashir A. and Gupta, Shishir K. and Tiwari, Sudeep and Rathor, Laxmi and Pant, Aakanksha and Singh, Nivedita and Gupta, Shailendra K. and Dandekar, Thomas and Pandey, Rakesh}, title = {C. elegans protein interaction network analysis probes RNAi validated pro-longevity effect of nhr-6, a human homolog of tumor suppressor Nr4a1}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-51649-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202666}, pages = {15711}, year = {2019}, abstract = {Protein-protein interaction (PPI) studies are gaining momentum these days due to the plethora of various high-throughput experimental methods available for detecting PPIs. Proteins create complexes and networks by functioning in harmony with other proteins and here in silico network biology hold the promise to reveal new functionality of genes as it is very difficult and laborious to carry out experimental high-throughput genetic screens in living organisms. We demonstrate this approach by computationally screening C. elegans conserved homologs of already reported human tumor suppressor and aging associated genes. We select by this nhr-6, vab-3 and gst-23 as predicted longevity genes for RNAi screen. The RNAi results demonstrated the pro-longevity effect of these genes. Nuclear hormone receptor nhr-6 RNAi inhibition resulted in a C. elegans phenotype of 23.46\% lifespan reduction. Moreover, we show that nhr-6 regulates oxidative stress resistance in worms and does not affect the feeding behavior of worms. These findings imply the potential of nhr-6 as a common therapeutic target for aging and cancer ailments, stressing the power of in silico PPI network analysis coupled with RNAi screens to describe gene function.}, language = {en} } @article{KehrbergerHolzschuh2019, author = {Kehrberger, Sandra and Holzschuh, Andrea}, title = {How does timing of flowering affect competition for pollinators, flower visitation and seed set in an early spring grassland plant?}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-51916-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202549}, pages = {15593}, year = {2019}, abstract = {Knowledge on how the timing of flowering is related to plant fitness and species interactions is crucial to understand consequences of phenological shifts as they occur under climate change. Early flowering plants may face advantages of low competition for pollinators and disadvantages of low pollinator abundances and unfavourable weather conditions. However, it is unknown how this trade-off changes over the season and how the timing affects reproductive success. On eight grasslands we recorded intra-seasonal changes in pollinators, co-flowering plants, weather conditions, flower visitation rates, floral longevity and seed set of Pulsatilla vulgaris. Although bee abundances and the number of pollinator-suitable hours were low at the beginning of the season, early flowers of P. vulgaris received higher flower visitation rates and estimated total number of bee visits than later flowers, which was positively related to seed set. Flower visitation rates decreased over time and with increasing number of co-flowering plants, which competed with P. vulgaris for pollinators. Low interspecific competition for pollinators seems to be a major driver for early flowering dates. Thus, non-synchronous temporal shifts of co-flowering plants as they may occur under climate warming can be expected to strongly affect plant-pollinator interactions and the fitness of the involved plants.}, language = {en} }