@article{BakariSoaleIkengaScheibeetal.2021, author = {Bakari-Soale, Majeed and Ikenga, Nonso Josephat and Scheibe, Marion and Butter, Falk and Jones, Nicola G. and Kramer, Susanne and Engstler, Markus}, title = {The nucleolar DExD/H protein Hel66 is involved in ribosome biogenesis in Trypanosoma brucei}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-97020-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-263872}, year = {2021}, abstract = {The biosynthesis of ribosomes is a complex cellular process involving ribosomal RNA, ribosomal proteins and several further trans-acting factors. DExD/H box proteins constitute the largest family of trans-acting protein factors involved in this process. Several members of this protein family have been directly implicated in ribosome biogenesis in yeast. In trypanosomes, ribosome biogenesis differs in several features from the process described in yeast. Here, we have identified the DExD/H box helicase Hel66 as being involved in ribosome biogenesis. The protein is unique to Kinetoplastida, localises to the nucleolus and its depletion via RNAi caused a severe growth defect. Loss of the protein resulted in a decrease of global translation and accumulation of rRNA processing intermediates for both the small and large ribosomal subunits. Only a few factors involved in trypanosome rRNA biogenesis have been described so far and our findings contribute to gaining a more comprehensive picture of this essential process.}, language = {en} } @article{LaswayKinaboMremietal.2021, author = {Lasway, Julius V. and Kinabo, Neema R. and Mremi, Rudolf F. and Martin, Emanuel H. and Nyakunga, Oliver C. and Sanya, John J. and Rwegasira, Gration M. and Lesio, Nicephor and Gideon, Hulda and Pauly, Alain and Eardley, Connal and Peters, Marcell K. and Peterson, Andrew T. and Steffan-Dewenter, Ingolf and Njovu, Henry K.}, title = {A synopsis of the Bee occurrence data of northern Tanzania}, series = {Biodiversity Data Journal}, volume = {9}, journal = {Biodiversity Data Journal}, doi = {10.3897/BDJ.9.e68190}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265018}, year = {2021}, abstract = {Background Bees (Hymenoptera: Apoidea: Anthophila) are the most important group of pollinators with about 20,507 known species worldwide. Despite the critical role of bees in providing pollination services, studies aiming at understanding which species are present across disturbance gradients are scarce. Limited taxononomic information for the existing and unidentified bee species in Tanzania make their conservation haphazard. Here, we present a dataset of bee species records obtained from a survey in nothern Tanzania i.e. Kilimanjaro, Arusha and Manyara regions. Our findings serve as baseline data necessary for understanding the diversity and distribution of bees in the northern parts of the country, which is a critical step in devising robust conservation and monitoring strategies for their populations. New information In this paper, we present information on 45 bee species belonging to 20 genera and four families sampled using a combination of sweep-netting and pan trap methods. Most species (27, ~ 60\%) belong to the family Halictidae followed by 16 species (35.5\%) from the family Apidae. Megachilidae and Andrenidae were the least represented, each with only one species (2.2\%). Additional species of Apidae and Megachilidae sampled during this survey are not yet published on Global Biodiversity Information Facility (GBIF), once they will be available on GBIF, they will be published in a subsequent paper. From a total of 953 occurrences, highest numbers were recorded in Kilimanjaro Region (n = 511), followed by Arusha (n = 410) and Manyara (n = 32), but this pattern reflects the sampling efforts of the research project rather than real bias in the distributions of bee species in northern Tanzania.}, language = {en} } @article{KhayenkoMaric2021, author = {Khayenko, Vladimir and Maric, Hans Michael}, title = {Innovative affinit{\"a}tsbasierte Markierungen f{\"u}r die High-End-Mikroskopie}, series = {BIOspektrum}, volume = {27}, journal = {BIOspektrum}, doi = {10.1007/s12268-021-1672-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287377}, pages = {709-712}, year = {2021}, abstract = {Advanced tissue imaging techniques and super resolution microscopy are opening new avenues of investigations in life sciences. These mainly instrumentation-driven innovations require the development of appropriate molecular labelling tools. Here, we discuss currently used and upcoming manipulation-free protein labelling strategies and their potential for the precise and interference-free visualization of endogenous proteins.}, language = {de} } @article{MayrKellerPetersetal.2021, author = {Mayr, Antonia V. and Keller, Alexander and Peters, Marcell K. and Grimmer, Gudrun and Krischke, Beate and Geyer, Mareen and Schmitt, Thomas and Steffan-Dewenter, Ingolf}, title = {Cryptic species and hidden ecological interactions of halictine bees along an elevational gradient}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {12}, doi = {10.1002/ece3.7605}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238853}, pages = {7700 -- 7712}, year = {2021}, abstract = {Changes of abiotic and biotic conditions along elevational gradients represent serious challenges to organisms which may promote the turnover of species, traits and biotic interaction partners. Here, we used molecular methods to study cuticular hydrocarbon (CHC) profiles, biotic interactions and phylogenetic relationships of halictid bees of the genus Lasioglossum along a 2,900 m elevational gradient at Mt. Kilimanjaro, Tanzania. We detected a strong species turnover of morphologically indistinguishable taxa with phylogenetically clustered cryptic species at high elevations, changes in CHC profiles, pollen resource diversity, and a turnover in the gut and body surface microbiome of bees. At high elevations, increased proportions of saturated compounds in CHC profiles indicate physiological adaptations to prevent desiccation. More specialized diets with higher proportions of low-quality Asteraceae pollen imply constraints in the availability of food resources. Interactive effects of climatic conditions on gut and surface microbiomes, CHC profiles, and pollen diet suggest complex feedbacks among abiotic conditions, ecological interactions, physiological adaptations, and phylogenetic constraints as drivers of halictid bee communities at Mt. Kilimanjaro.}, language = {en} } @article{DuquePoelmanSteffanDewenter2021, author = {Duque, Laura and Poelman, Erik H. and Steffan-Dewenter, Ingolf}, title = {Plant age at the time of ozone exposure affects flowering patterns, biotic interactions and reproduction of wild mustard}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-02878-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265742}, year = {2021}, abstract = {Exposure of plants to environmental stressors can modify their metabolism, interactions with other organisms and reproductive success. Tropospheric ozone is a source of plant stress. We investigated how an acute exposure to ozone at different times of plant development affects reproductive performance, as well as the flowering patterns and the interactions with pollinators and herbivores, of wild mustard plants. The number of open flowers was higher on plants exposed to ozone at earlier ages than on the respective controls, while plants exposed at later ages showed a tendency for decreased number of open flowers. The changes in the number of flowers provided a good explanation for the ozone-induced effects on reproductive performance and on pollinator visitation. Ozone exposure at earlier ages also led to either earlier or extended flowering periods. Moreover, ozone tended to increase herbivore abundance, with responses depending on herbivore taxa and the plant age at the time of ozone exposure. These results suggest that the effects of ozone exposure depend on the developmental stage of the plant, affecting the flowering patterns in different directions, with consequences for pollination and reproduction of annual crops and wild species.}, language = {en} } @article{UhlerRedlichZhangetal.2021, author = {Uhler, Johannes and Redlich, Sarah and Zhang, Jie and Hothorn, Torsten and Tobisch, Cynthia and Ewald, J{\"o}rg and Thorn, Simon and Seibold, Sebastian and Mitesser, Oliver and Morin{\`e}re, J{\´e}r{\^o}me and Bozicevic, Vedran and Benjamin, Caryl S. and Englmeier, Jana and Fricke, Ute and Ganuza, Cristina and Haensel, Maria and Riebl, Rebekka and Rojas-Botero, Sandra and Rummler, Thomas and Uphus, Lars and Schmidt, Stefan and Steffan-Dewenter, Ingolf and M{\"u}ller, J{\"o}rg}, title = {Relationships of insect biomass and richness with land use along a climate gradient}, series = {Nature Communications}, volume = {12}, journal = {Nature Communications}, number = {1}, doi = {10.1038/s41467-021-26181-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265058}, year = {2021}, abstract = {Recently reported insect declines have raised both political and social concern. Although the declines have been attributed to land use and climate change, supporting evidence suffers from low taxonomic resolution, short time series, a focus on local scales, and the collinearity of the identified drivers. In this study, we conducted a systematic assessment of insect populations in southern Germany, which showed that differences in insect biomass and richness are highly context dependent. We found the largest difference in biomass between semi-natural and urban environments (-42\%), whereas differences in total richness (-29\%) and the richness of threatened species (-56\%) were largest from semi-natural to agricultural environments. These results point to urbanization and agriculture as major drivers of decline. We also found that richness and biomass increase monotonously with increasing temperature, independent of habitat. The contrasting patterns of insect biomass and richness question the use of these indicators as mutual surrogates. Our study provides support for the implementation of more comprehensive measures aimed at habitat restoration in order to halt insect declines.}, language = {en} } @article{HartkeWaldvogelSprengeretal.2021, author = {Hartke, Juliane and Waldvogel, Ann-Marie and Sprenger, Philipp P. and Schmitt, Thomas and Menzel, Florian and Pfenninger, Markus and Feldmeyer, Barbara}, title = {Little parallelism in genomic signatures of local adaptation in two sympatric, cryptic sister species}, series = {Journal of Evolutionary Biology}, volume = {34}, journal = {Journal of Evolutionary Biology}, number = {6}, doi = {10.1111/jeb.13742}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228355}, pages = {937 -- 952}, year = {2021}, abstract = {Species living in sympatry and sharing a similar niche often express parallel phenotypes as a response to similar selection pressures. The degree of parallelism within underlying genomic levels is often unexplored, but can give insight into the mechanisms of natural selection and adaptation. Here, we use multi-dimensional genomic associations to assess the basis of local and climate adaptation in two sympatric, cryptic Crematogaster levior ant species along a climate gradient. Additionally, we investigate the genomic basis of chemical communication in both species. Communication in insects is mainly mediated by cuticular hydrocarbons (CHCs), which also protect against water loss and, hence, are subject to changes via environmental acclimation or adaptation. The combination of environmental and chemical association analyses based on genome-wide Pool-Seq data allowed us to identify single nucleotide polymorphisms (SNPs) associated with climate and with chemical differences. Within species, CHC changes as a response to climate seem to be driven by phenotypic plasticity, since there is no overlap between climate- and CHC-associated SNPs. The only exception is the odorant receptor OR22c, which may be a candidate for population-specific CHC recognition in one of the species. Within both species, climate is significantly correlated with CHC differences, as well as to allele frequency differences. However, associated candidate SNPs, genes and functions are largely species-specific and we find evidence for minimal parallel evolution only on the level of genomic regions (J = 0.04). This highlights that even closely related species may follow divergent evolutionary trajectories when expressing similar adaptive phenotypes.}, language = {en} } @article{YeKeicherGentschevetal.2021, author = {Ye, Mingyu and Keicher, Markus and Gentschev, Ivaylo and Szalay, Aladar A.}, title = {Efficient selection of recombinant fluorescent vaccinia virus strains and rapid virus titer determination by using a multi-well plate imaging system}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {8}, issn = {2227-9059}, doi = {10.3390/biomedicines9081032}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245104}, year = {2021}, abstract = {Engineered vaccinia virus (VACV) strains are used extensively as vectors for the development of novel cancer vaccines and cancer therapeutics. In this study, we describe for the first time a high-throughput approach for both fluorescent rVACV generation and rapid viral titer measurement with the multi-well plate imaging system, IncuCyte\(^®\)S3. The isolation of a single, well-defined plaque is critical for the generation of novel recombinant vaccinia virus (rVACV) strains. Unfortunately, current methods of rVACV engineering via plaque isolation are time-consuming and laborious. Here, we present a modified fluorescent viral plaque screening and selection strategy that allows one to generally obtain novel fluorescent rVACV strains in six days, with a minimum of just four days. The standard plaque assay requires chemicals for fixing and staining cells. Manual plaque counting based on visual inspection of the cell culture plates is time-consuming. Here, we developed a fluorescence-based plaque assay for quantifying the vaccinia virus that does not require a cell staining step. This approach is less toxic to researchers and is reproducible; it is thus an improvement over the traditional assay. Lastly, plaque counting by virtue of a fluorescence-based image is very convenient, as it can be performed directly on the computer.}, language = {en} } @phdthesis{Eiring2021, author = {Eiring, Patrick}, title = {Super-resolution microscopy of plasma membrane receptors}, doi = {10.25972/OPUS-25004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250048}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Plasma membrane receptors are the most crucial and most commonly studied components of cells, since they not only ensure communication between the extracellular space and cells, but are also responsible for the regulation of cell cycle and cell division. The composition of the surface receptors, the so-called "Receptome", differs and is characteristic for certain cell types. Due to their significance, receptors have been important target structures for diagnostic and therapy in cancer medicine and often show aberrant expression patterns in various cancers compared to healthy cells. However, these aberrations can also be exploited and targeted by different medical approaches, as in the case of personalized immunotherapy. In addition, advances in modern fluorescence microscopy by so-called single molecule techniques allow for unprecedented sensitive visualization and quantification of molecules with an attainable spatial resolution of 10-20 nm, allowing for the detection of both stoichiometric and expression density differences. In this work, the single molecule sensitive method dSTORM was applied to quantify the receptor composition of various cell lines as well as in primary samples obtained from patients with hematologic malignancies. The focus of this work lies on artefact free quantification, stoichiometric analyses of oligomerization states and co localization analyses of membrane receptors. Basic requirements for the quantification of receptors are dyes with good photoswitching properties and labels that specifically mark the target structure without generating background through non-specific binding. To ensure this, antibodies with a predefined DOL (degree of labeling) were used, which are also standard in flow cytometry. First background reduction protocols were established on cell lines prior analyses in primary patient samples. Quantitative analyses showed clear expression differences between the cell lines and the patient cells, but also between individual patients. An important component of this work is the ability to detect the oligomerization states of receptors, which enables a more accurate quantification of membrane receptor densities compared to standard flow cytometry. It also provides information about the activation of a certain receptor, for example of FLT3, a tyrosine kinase, dimerizing upon activation. For this purpose, different well-known monomers and dimers were compared to distinguish the typical localization statistics of single bound antibodies from two or more antibodies that are in proximity. Further experiments as well as co localization analyses proved that antibodies can bind to closely adjacent epitopes despite their size. These analytical methods were subsequently applied for quantification and visualization of receptors in two clinically relevant examples. Firstly, various therapeutically relevant receptors such as CD38, BCMA and SLAMF7 for multiple myeloma, a malignant disease of plasma cells, were analyzed and quantified on patient cells. Furthermore, the influence of TP53 and KRAS mutations on receptor expression levels was investigated using the multiple myeloma cell lines OPM2 and AMO1, showing clear differences in certain receptor quantities. Secondly, FLT3 which is a therapeutic target receptor for acute myeloid leukemia, was quantified and stoichiometrically analyzed on both cell lines and patient cells. In addition, cells that have developed resistance against midostaurin were compared with cells that still respond to this type I tyrosine-kinase-inhibitor for their FLT3 receptor expression and oligomerization state.}, subject = {Fluoreszenzmikroskopie}, language = {en} } @phdthesis{CruzGarcia2021, author = {Cruz Garcia, Yiliam}, title = {Interactome of the β2b subunit of L-type voltage-gated calcium channels in cardiomyocytes}, doi = {10.25972/OPUS-20857}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208579}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {L-type voltage-gated calcium channels (LTCC) are heteromultimeric membrane proteins that allow Ca2+ entry into the cell upon plasma membrane depolarization. The β subunit of voltage-dependent calcium channels (Cavβ) binds to the α-interaction domain in the pore-forming α1 subunit and regulates the trafficking and biophysical properties of these channels. Of the four Cavβ isoforms, Cavβ2 is predominantly expressed in cardiomyocytes. This subunit associates with diverse proteins besides LTCC, but the molecular composition of the Cavβ2 nanoenvironments in cardiomyocytes is yet unresolved. Here, we used a protein-labeling technique in living cells based on an engineered ascorbate peroxidase 2 (APEX2). In this strategy, Cavβ2b was fused to APEX2 and expressed in adult rat cardiomyocytes using an adenovirus system. Nearby proteins covalently labeled with biotin-phenol were purified using streptavidin-coated beads and identified by mass spectrometry (MS). Analysis of the in situ APEX2-based biotin labeling by MS revealed 61 proteins located in the nanoenvironments of Cavβ2b, with a high specificity and consistency in all the replicates. These proteins are involved in diverse cellular functions such as cellular trafficking, sarcomere organization and excitation-contraction coupling. Among these proteins, we demonstrated an interaction between the ryanodine receptor 2 (RyR2) and Cavβ2b, probably coupling LTCC and the RyR2 into a supramolecular complex at the dyads. This interaction is mediated by the Src homology 3 (SH3) domain of Cavβ2b and is necessary for an effective pacing frequency-dependent increase in Ca2+-induced Ca2+ release in cardiomyocytes.}, subject = {Calciumkanal}, language = {en} } @article{WelterWagnerFurtwaengleretal.2021, author = {Welter, Nils and Wagner, Angelo and Furtw{\"a}ngler, Rhoikos and Melchior, Patrick and Kager, Leo and Vokuhl, Christian and Schenk, Jens-Peter and Meier, Clemens Magnus and Siemer, Stefan and Gessler, Manfred and Graf, Norbert}, title = {Correction: Welter et al. Characteristics of nephroblastoma/nephroblastomatosis in children with a clinically reported underlying malformation or cancer predisposition syndrome. Cancers 2021, 13, 5016}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {22}, issn = {2072-6694}, doi = {10.3390/cancers13225743}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250135}, year = {2021}, abstract = {In the original article [1] there was a mistake in Table 2 as published. Table 2 contains wrong percentages in lines Bilateral disease and Patients with CPS or GU. For this reason the table should be replaced with the correct one as shown below.}, language = {en} } @article{GuptaSrivastavaOsmanogluetal.2021, author = {Gupta, Shishir K. and Srivastava, Mugdha and Osmanoglu, {\"O}zge and Xu, Zhuofei and Brakhage, Axel A. and Dandekar, Thomas}, title = {Aspergillus fumigatus versus genus Aspergillus: conservation, adaptive evolution and specific virulence genes}, series = {Microorganisms}, volume = {9}, journal = {Microorganisms}, number = {10}, issn = {2076-2607}, doi = {10.3390/microorganisms9102014}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246318}, year = {2021}, abstract = {Aspergillus is an important fungal genus containing economically important species, as well as pathogenic species of animals and plants. Using eighteen fungal species of the genus Aspergillus, we conducted a comprehensive investigation of conserved genes and their evolution. This also allows us to investigate the selection pressure driving the adaptive evolution in the pathogenic species A. fumigatus. Among single-copy orthologs (SCOs) for A. fumigatus and the closely related species A. fischeri, we identified 122 versus 50 positively selected genes (PSGs), respectively. Moreover, twenty conserved genes of unknown function were established to be positively selected and thus important for adaption. A. fumigatus PSGs interacting with human host proteins show over-representation of adaptive, symbiosis-related, immunomodulatory and virulence-related pathways, such as the TGF-β pathway, insulin receptor signaling, IL1 pathway and interfering with phagosomal GTPase signaling. Additionally, among the virulence factor coding genes, secretory and membrane protein-coding genes in multi-copy gene families, 212 genes underwent positive selection and also suggest increased adaptation, such as fungal immune evasion mechanisms (aspf2), siderophore biosynthesis (sidD), fumarylalanine production (sidE), stress tolerance (atfA) and thermotolerance (sodA). These genes presumably contribute to host adaptation strategies. Genes for the biosynthesis of gliotoxin are shared among all the close relatives of A. fumigatus as an ancient defense mechanism. Positive selection plays a crucial role in the adaptive evolution of A. fumigatus. The genome-wide profile of PSGs provides valuable targets for further research on the mechanisms of immune evasion, antimycotic targeting and understanding fundamental virulence processes.}, language = {en} } @article{WagnerSlaghuisGoebeletal.2021, author = {Wagner, Martin and Slaghuis, J{\"o}rg and G{\"o}bel, Werner and V{\´a}zquez-Boland, Jos{\´e} Antonio and Rychli, Kathrin and Schmitz-Esser, Stephan}, title = {Virulence pattern analysis of three Listeria monocytogenes lineage I epidemic strains with distinct outbreak histories}, series = {Microorganisms}, volume = {9}, journal = {Microorganisms}, number = {8}, issn = {2076-2607}, doi = {10.3390/microorganisms9081745}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245093}, year = {2021}, abstract = {Strains of the food-borne pathogen Listeria (L.) monocytogenes have diverse virulence potential. This study focused on the virulence of three outbreak strains: the CC1 strain PF49 (serovar 4b) from a cheese-associated outbreak in Switzerland, the clinical CC2 strain F80594 (serovar 4b), and strain G6006 (CC3, serovar 1/2a), responsible for a large gastroenteritis outbreak in the USA due to chocolate milk. We analysed the genomes and characterized the virulence in vitro and in vivo. Whole-genome sequencing revealed a high conservation of the major virulence genes. Minor deviations of the gene contents were found in the autolysins Ami, Auto, and IspC. Moreover, different ActA variants were present. Strain PF49 and F80594 showed prolonged survival in the liver of infected mice. Invasion and intracellular proliferation were similar for all strains, but the CC1 and CC2 strains showed increased spreading in intestinal epithelial Caco2 cells compared to strain G6006. Overall, this study revealed long-term survival of serovar 4b strains F80594 and PF49 in the liver of mice. Future work will be needed to determine the genes and molecular mechanism behind the long-term survival of L. monocytogenes strains in organs.}, language = {en} } @article{WelterWagnerFurtwaengleretal.2021, author = {Welter, Nils and Wagner, Angelo and Furtw{\"a}ngler, Rhoikos and Melchior, Patrick and Kager, Leo and Vokuhl, Christian and Schenk, Jens-Peter and Meier, Clemens Magnus and Siemer, Stefan and Gessler, Manfred and Graf, Norbert}, title = {Characteristics of nephroblastoma/nephroblastomatosis in children with a clinically reported underlying malformation or cancer predisposition syndrome}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {19}, issn = {2072-6694}, doi = {10.3390/cancers13195016}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-248434}, year = {2021}, abstract = {(1) Background: about 10\% of Wilms Tumor (WT) patients have a malformation or cancer predisposition syndrome (CPS) with causative germline genetic or epigenetic variants. Knowledge on CPS is essential for genetic counselling. (2) Methods: this retrospective analysis focused on 2927 consecutive patients with WTs registered between 1989 and 2017 in the SIOP/GPOH studies. (3) Results: Genitourinary malformations (GU, N = 66, 2.3\%), Beckwith-Wiedemann spectrum (BWS, N = 32, 1.1\%), isolated hemihypertrophy (IHH, N = 29, 1.0\%), Denys-Drash syndrome (DDS, N = 24, 0.8\%) and WAGR syndrome (N = 20, 0.7\%) were reported most frequently. Compared to others, these patients were younger at WT diagnosis (median age 24.5 months vs. 39.0 months), had smaller tumors (349.4 mL vs. 487.5 mL), less often metastasis (8.2\% vs. 18\%), but more often nephroblastomatosis (12.9\% vs. 1.9\%). WT with IHH was associated with blastemal WT and DDS with stromal subtype. Bilateral WTs were common in WAGR (30\%), DDS (29\%) and BWS (31\%). Chemotherapy induced reduction in tumor volume was poor in DDS (0.4\% increase) and favorable in BWS (86.9\% reduction). The event-free survival (EFS) of patients with BWS was significantly (p = 0.002) worse than in others. (4) Conclusions: CPS should be considered in WTs with specific clinical features resulting in referral to a geneticist. Their outcome was not always favorable.}, language = {en} } @article{HempelmannHartlebvanStraatenetal.2021, author = {Hempelmann, Alexander and Hartleb, Laura and van Straaten, Monique and Hashemi, Hamidreza and Zeelen, Johan P. and Bongers, Kevin and Papavasiliou, F. Nina and Engstler, Markus and Stebbins, C. Erec and Jones, Nicola G.}, title = {Nanobody-mediated macromolecular crowding induces membrane fission and remodeling in the African trypanosome}, series = {Cell Reports}, volume = {37}, journal = {Cell Reports}, number = {5}, doi = {10.1016/j.celrep.2021.109923}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270285}, year = {2021}, abstract = {The dense variant surface glycoprotein (VSG) coat of African trypanosomes represents the primary host-pathogen interface. Antigenic variation prevents clearing of the pathogen by employing a large repertoire of antigenically distinct VSG genes, thus neutralizing the host's antibody response. To explore the epitope space of VSGs, we generate anti-VSG nanobodies and combine high-resolution structural analysis of VSG-nanobody complexes with binding assays on living cells, revealing that these camelid antibodies bind deeply inside the coat. One nanobody causes rapid loss of cellular motility, possibly due to blockage of VSG mobility on the coat, whose rapid endocytosis and exocytosis are mechanistically linked to Trypanosoma brucei propulsion and whose density is required for survival. Electron microscopy studies demonstrate that this loss of motility is accompanied by rapid formation and shedding of nanovesicles and nanotubes, suggesting that increased protein crowding on the dense membrane can be a driving force for membrane fission in living cells.}, language = {en} } @article{KriegelMatevskiSchuldt2021, author = {Kriegel, Peter and Matevski, Dragan and Schuldt, Andreas}, title = {Monoculture and mixture-planting of non-native Douglas fir alters species composition, but promotes the diversity of ground beetles in a temperate forest system}, series = {Biodiversity and Conservation}, volume = {30}, journal = {Biodiversity and Conservation}, number = {5}, issn = {1572-9710}, doi = {10.1007/s10531-021-02155-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269017}, pages = {1479-1499}, year = {2021}, abstract = {Planting non-native tree species, like Douglas fir in temperate European forest systems, is encouraged to mitigate effects of climate change. However, Douglas fir monocultures often revealed negative effects on forest biota, while effects of mixtures with native tree species on forest ecosystems are less well understood. We investigated effects of three tree species (Douglas fir, Norway spruce, native European beech), on ground beetles in temperate forests of Germany. Beetles were sampled in monocultures of each tree species and broadleaf-conifer mixtures with pitfall traps, and environmental variables were assessed around each trap. We used linear mixed models in a two-step procedure to disentangle effects of environment and tree species identity on ground beetle abundance, species richness, functional diversity and species assemblage structure. Contradictory to our expectations, ground beetle abundance and functional diversity was highest in pure Douglas fir stands, while tree mixtures showed intermediate values between pure coniferous and pure beech stands. The main drivers of these patterns were only partially dependent on tree species identity, which highlights the importance of structural features in forest stands. However, our study revealed distinct shifts in assemblage structure between pure beech and pure Douglas fir stands, which were only partially eased through mixture planting. Our findings suggest that effects of planting non-native trees on associated biodiversity can be actively modified by promoting beneficial forest structures. Nevertheless, integrating non-native tree species, even in mixtures with native trees, will invariably alter assemblage structures of associated biota, which can compromise conservation efforts targeted at typical species composition.}, language = {en} } @article{PeixotoJanakiRamanSchlickeretal.2021, author = {Peixoto, Joana and Janaki-Raman, Sudha and Schlicker, Lisa and Schmitz, Werner and Walz, Susanne and Winkelkotte, Alina M. and Herold-Mende, Christel and Soares, Paula and Schulze, Almut and Lima, Jorge}, title = {Integrated metabolomics and transcriptomics analysis of monolayer and neurospheres from established glioblastoma cell lines}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {6}, issn = {2072-6694}, doi = {10.3390/cancers13061327}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234110}, year = {2021}, abstract = {Altered metabolic processes contribute to carcinogenesis by modulating proliferation, survival and differentiation. Tumours are composed of different cell populations, with cancer stem-like cells being one of the most prominent examples. This specific pool of cells is thought to be responsible for cancer growth and recurrence and plays a particularly relevant role in glioblastoma (GBM), the most lethal form of primary brain tumours. Here, we have analysed the transcriptome and metabolome of an established GBM cell line (U87) and a patient-derived GBM stem-like cell line (NCH644) exposed to neurosphere or monolayer culture conditions. By integrating transcriptome and metabolome data, we identified key metabolic pathways and gene signatures that are associated with stem-like and differentiated states in GBM cells, and demonstrated that neurospheres and monolayer cells differ substantially in their metabolism and gene regulation. Furthermore, arginine biosynthesis was identified as the most significantly regulated pathway in neurospheres, although individual nodes of this pathway were distinctly regulated in the two cellular systems. Neurosphere conditions, as opposed to monolayer conditions, cause a transcriptomic and metabolic rewiring that may be crucial for the regulation of stem-like features, where arginine biosynthesis may be a key metabolic pathway. Additionally, TCGA data from GBM patients showed significant regulation of specific components of the arginine biosynthesis pathway, providing further evidence for the importance of this metabolic pathway in GBM.}, language = {en} } @phdthesis{Staus2021, author = {Staus, Madlen}, title = {Glutathione-dependent reprogramming in melanoma}, doi = {10.25972/OPUS-16842}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168424}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {These days, treatment of melanoma patients relies on targeted therapy with BRAF/MEK inhibitors and on immunotherapy. About half of all patients initially respond to existing therapies. Nevertheless, the identification of alternative therapies for melanoma patients with intrinsic or acquired resistance is of great importance. In melanoma, antioxidants play an essential role in the maintenance of the redox homeostasis. Therefore, disruption of the redox homeostasis is regarded as highly therapeutically relevant and is the focus of the present work. An adequate supply of cysteine is essential for the production of the most important intracellular antioxidants, such as glutathione. In the present work, it was investigated whether the depletion of cysteine and glutathione is therapeutically useful. Depletion of glutathione in melanoma cells could be achieved by blocking cysteine supply, glutathione synthesis, and NADPH regeneration. As expected, this led to an increased level of reactive oxygen species (ROS). Surprisingly, however, these changes did not impair the proliferation and survival of the melanoma cells. In contrast, glutathione depletion led to cellular reprogramming which was characterized by the induction of mesenchymal genes and the repression of differentiation markers (phenotypic switch). This was accompanied by an increased migration and invasion potential which was favored by the induction of the transcription factor FOSL1. To study in vivo reprogramming, Gclc, the first and rate-limiting enzyme in glutathione synthesis, was knocked out by CRISPR/Cas9 in murine melanoma cells. The cells were devoid of glutathione, but were fully viable and showed a phenotypic switch, the latter only in MITF-expressing B16F1 cells and not in MITF-deficient D4M3A.781 cells. Following subcutaneous injection into immunocompetent C57BL/6 mice, Gclc knockout B16F1 cells grew more aggressively and resulted in an earlier tumor onset than B16F1 control cells. In summary, this work demonstrates that inhibition of cysteine supply and thus, glutathione synthesis leads to cellular reprogramming in melanoma. In this context, melanoma cells show metastatic capabilities, promoting a more aggressive form of the disease.}, subject = {Melanom}, language = {en} } @article{RotherKraftSmithetal.2021, author = {Rother, Lisa and Kraft, Nadine and Smith, Dylan B. and El Jundi, Basil and Gill, Richard J. and Pfeiffer, Keram}, title = {A micro-CT-based standard brain atlas of the bumblebee}, series = {Cell and Tissue Research}, volume = {386}, journal = {Cell and Tissue Research}, number = {1}, issn = {1432-0878}, doi = {10.1007/s00441-021-03482-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267783}, pages = {29-45}, year = {2021}, abstract = {In recent years, bumblebees have become a prominent insect model organism for a variety of biological disciplines, particularly to investigate learning behaviors as well as visual performance. Understanding these behaviors and their underlying neurobiological principles requires a clear understanding of brain anatomy. Furthermore, to be able to compare neuronal branching patterns across individuals, a common framework is required, which has led to the development of 3D standard brain atlases in most of the neurobiological insect model species. Yet, no bumblebee 3D standard brain atlas has been generated. Here we present a brain atlas for the buff-tailed bumblebee Bombus terrestris using micro-computed tomography (micro-CT) scans as a source for the raw data sets, rather than traditional confocal microscopy, to produce the first ever micro-CT-based insect brain atlas. We illustrate the advantages of the micro-CT technique, namely, identical native resolution in the three cardinal planes and 3D structure being better preserved. Our Bombus terrestris brain atlas consists of 30 neuropils reconstructed from ten individual worker bees, with micro-CT allowing us to segment neuropils completely intact, including the lamina, which is a tissue structure often damaged when dissecting for immunolabeling. Our brain atlas can serve as a platform to facilitate future neuroscience studies in bumblebees and illustrates the advantages of micro-CT for specific applications in insect neuroanatomy.}, language = {en} } @article{LeidingerVedderCabral2021, author = {Leidinger, Ludwig and Vedder, Daniel and Cabral, Juliano Sarmento}, title = {Temporal environmental variation may impose differential selection on both genomic and ecological traits}, series = {Oikos}, volume = {130}, journal = {Oikos}, number = {7}, doi = {10.1111/oik.08172}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238945}, pages = {1100 -- 1115}, year = {2021}, abstract = {The response of populations and species to changing conditions determines how community composition will change functionally, including via trait shifts. Selection from standing variation has been suggested to be more efficient than acquiring new mutations. Yet, studies on community trait composition and trait selection largely focus on phenotypic variation in ecological traits, whereas the underlying genomic traits remain understudied. Using a genome-explicit, niche- and individual-based model, we address the potential interactions between genomic and ecological traits shaping communities under an environmental selective forcing, namely temporal positively autocorrelated environmental fluctuation. In this model, all ecological traits are explicitly coded by the genome. For our experiments, we initialized 90 replicate communities, each with ca 350 initial species, characterized by random genomic and ecological trait combinations, on a 2D spatially explicit landscape with two orthogonal gradients (temperature and resource use). We exposed each community to two contrasting scenarios: without (i.e. static environments) and with temporal variation. We then analyzed emerging compositions of both genomic and ecological traits at the community, population and genomic levels. Communities in variable environments were species poorer than in static environments, and populations more abundant, whereas genomes had lower genetic linkage, mean genetic variation and a non-significant tendency towards higher numbers of genes. The surviving genomes (i.e. those selected by variable environments) coded for enhanced environmental tolerance and smaller biomass, which resulted in faster life cycles and thus also in increased potential for evolutionary rescue. Under temporal environmental variation, larger, less linked genomes retained more variation in mean dispersal ability at the population level than at genomic level, whereas the opposite trend emerged for biomass. Our results provide clues to how sexually-reproducing diploid plant communities might react to variable environments and highlights the importance of genomic traits and their interaction with ecological traits for eco-evolutionary responses to changing climates.}, language = {en} } @article{SponslerBratman2021, author = {Sponsler, Douglas B. and Bratman, Eve Z.}, title = {Beekeeping in, of or for the city? A socioecological perspective on urban apiculture}, series = {People and Nature}, volume = {3}, journal = {People and Nature}, number = {3}, doi = {10.1002/pan3.10206}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239949}, pages = {550 -- 559}, year = {2021}, abstract = {The term 'urban beekeeping' connotes a host of meanings—sociopolitical, commercial, ecological and personal—beyond the mere description of where bees and beekeepers happen to coincide. Yet, these meanings are seldom articulated explicitly or brought into critical engagement with the relevant fields of urban ecology and political ecology. Beginning with a brief account of the history of urban beekeeping in the United States, we draw upon urban ecological theory to construct a conceptual model of urban beekeeping that distinguishes beekeeping in, of and for the city. In our model, beekeeping in the city describes the mere importation of the traditionally rural practice of beekeeping into urban spaces for the private reasons of the individual beekeeper, whereas beekeeping of the city describes beekeeping that is consciously tailored to the urban context, often accompanied by (semi)professionalization of beekeepers and the formation of local expert communities (i.e. beekeeping associations). Beekeeping for the city describes a shift in mindset in which beekeeping is directed to civic ends beyond the boundaries of the beekeeping community per se. Using this framework, we identify and discuss specific socioecological assets and liabilities of urban beekeeping, and how these relate to beekeeping in, of and for the city. We then formulate actionable guidelines for maturing the practice of urban beekeeping into a beneficent and self-critical form of urban ecological citizenship; these include fostering self-regulation within the beekeeping community, harnessing beekeeping as a 'gateway' experience for a broader rapprochement between urban residents and nature, and recognizing the political-ecological context of beekeeping with respect to matters of socioecological justice.}, language = {en} } @article{KriegelFritzeThorn2021, author = {Kriegel, Peter and Fritze, Michael-Andreas and Thorn, Simon}, title = {Surface temperature and shrub cover drive ground beetle (Coleoptera: Carabidae) assemblages in short-rotation coppices}, series = {Agricultural and Forest Entomology}, volume = {23}, journal = {Agricultural and Forest Entomology}, number = {4}, doi = {10.1111/afe.12441}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239873}, pages = {400 -- 410}, year = {2021}, abstract = {Increasing demand for biomass has led to an on-going intensification of fuel wood plantations with possible negative effects on open land biodiversity. Hence, ecologists increasingly call for measures that reduce those negative effects on associated biodiversity. However, our knowledge about the efficiency of such measures remains scarce. We investigated the effects of gap implementation in short rotation coppices (SRCs) on carabid diversity and assemblage composition over 3 years, with pitfall traps in gaps, edges and interiors. In parallel, we quantified soil surface temperature, shrub- and herb cover. Edges had the highest number of species and abundances per trap, whereas rarefied species richness was significantly lower in short rotation coppice interiors than in other habitat types. Carabid community composition differed significantly between habitat types. The main environmental drivers were temperature for number of species and abundance and shrub cover for rarefied species richness. We found significantly higher rarefied species richness in gaps compared with interiors. Hence, we argue that gap implementation benefits overall diversity in short rotation coppices. Furthermore, the differences in species community composition between habitat types through increased species turnover support carabid diversity in short rotation coppices. These positive effects were largely attributed to microclimate conditions. However, to maintain positive effects, continuous management of herb layer might be necessary.}, language = {en} } @article{Wolf2021, author = {Wolf, Matthias}, title = {How to teach about what is a species}, series = {Biology}, volume = {10}, journal = {Biology}, number = {6}, issn = {2079-7737}, doi = {10.3390/biology10060523}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241052}, year = {2021}, abstract = {To ask students what a species is always has something rhetorical about it. Too quickly comes the rote answer, often learned by heart without ever thinking about it: "A species is a reproductive community of populations (reproductively isolated from others), which occupies a specific niche in nature" (Mayr 1982). However, do two people look alike because they are twins or are they twins because they look alike? "Two organisms do not belong to the same species because they mate and reproduce, but they only are able to do so because they belong to the same species" (Mahner and Bunge 1997). Unfortunately, most biology (pre-university) teachers have no opinion on whether species are real or conceptual, simply because they have never been taught the question themselves, but rather one answer they still pass on to their students today, learned by heart without ever thinking about it. Species are either real or conceptual and, in my opinion, it is this "or" that we should teach about. Only then can we discuss those fundamental questions such as who or what is selected, who or what evolves and, finally, what is biodiversity and phylogenetics all about? Individuals related to each other by the tree of life.}, language = {en} } @article{KouhestaniGeisAlsourietal.2021, author = {Kouhestani, Dina and Geis, Maria and Alsouri, Saed and Bumm, Thomas G. P. and Einsele, Hermann and Sauer, Markus and Stuhler, Gernot}, title = {Variant signaling topology at the cancer cell-T-cell interface induced by a two-component T-cell engager}, series = {Cellular \& Molecular Immunology}, volume = {18}, journal = {Cellular \& Molecular Immunology}, doi = {10.1038/s41423-020-0507-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241189}, pages = {1568-1570}, year = {2021}, abstract = {No abstract available.}, language = {en} } @article{LoosKraussLyonsetal.2021, author = {Loos, Jacqueline and Krauss, Jochen and Lyons, Ashley and F{\"o}st, Stephanie and Ohlendorf, Constanze and Racky, Severin and R{\"o}der, Marina and Hudel, Lennart and Herfert, Volker and Tscharntke, Teja}, title = {Local and landscape responses of biodiversity in calcareous grasslands}, series = {Biodiversity and Conservation}, volume = {30}, journal = {Biodiversity and Conservation}, number = {8-9}, issn = {0960-3115}, doi = {10.1007/s10531-021-02201-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308595}, pages = {2415-2432}, year = {2021}, abstract = {Across Europe, calcareous grasslands become increasingly fragmented and their quality deteriorates through abandonment and land use intensification, both affecting biodiversity. Here, we investigated local and landscape effects on diversity patterns of several taxonomic groups in a landscape of highly fragmented calcareous grassland remnants. We surveyed 31 grassland fragments near G{\"o}ttingen, Germany, in spring and summer 2017 for vascular plants, butterflies and birds, with sampling effort adapted to fragment area. Through regression modelling, we tested relationships between species richness and fragment size (from 314 to 51,395 m\(^2\)), successional stage, habitat connectivity and the per cent cover of arable land in the landscape at several radii. We detected 283 plant species, 53 butterfly species and 70 bird species. Of these, 59 plant species, 19 butterfly species and 9 bird species were grassland specialists. Larger fragments supported twice the species richness of plants than small ones, and hosted more species of butterflies, but not of birds. Larger grassland fragments contained more grassland specialist plants, but not butterfly or bird specialists. Increasing amounts of arable land in the landscape from 20 to 90\% was related to the loss of a third of species of plants, and less so, of butterflies, but not of birds. Per cent cover of arable land negatively correlated to richness of grassland specialist plants and butterflies, but positively to grassland specialist birds. We found no effect by successional stages and habitat connectivity. Our multi-taxa approach highlights the need for conservation management at the local scale, complemented by measures at the landscape scale.}, language = {en} } @article{RiedmeierDecarolisHaubitzetal.2021, author = {Riedmeier, Maria and Decarolis, Boris and Haubitz, Imme and M{\"u}ller, Sophie and Uttinger, Konstantin and B{\"o}rner, Kevin and Reibetanz, Joachim and Wiegering, Armin and H{\"a}rtel, Christoph and Schlegel, Paul-Gerhardt and Fassnacht, Martin and Wiegering, Verena}, title = {Adrenocortical carcinoma in childhood: a systematic review}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {21}, issn = {2072-6694}, doi = {10.3390/cancers13215266}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-248507}, year = {2021}, abstract = {Adrenocortical tumors are rare in children. This systematic review summarizes the published evidence on pediatric adrenocortical carcinoma (ACC) to provide a basis for a better understanding of the disease, investigate new molecular biomarkers and therapeutic targets, and define which patients may benefit from a more aggressive therapeutic approach. We included 137 studies with 3680 ACC patients (~65\% female) in our analysis. We found no randomized controlled trials, so this review mainly reflects retrospective data. Due to a specific mutation in the TP53 gene in ~80\% of Brazilian patients, that cohort was analyzed separately from series from other countries. Hormone analysis was described in 2569 of the 2874 patients (89\%). Most patients were diagnosed with localized disease, whereas 23\% had metastasis at primary diagnosis. Only 72\% of the patients achieved complete resection. In 334 children (23\%), recurrent disease was reported: 81\% — local recurrence, 19\% (n = 65) — distant metastases at relapse. Patients < 4 years old had a different distribution of tumor stages and hormone activity and better overall survival (p < 0.001). Although therapeutic approaches are typically multimodal, no consensus is available on effective standard treatments for advanced ACC. Thus, knowledge regarding pediatric ACC is still scarce and international prospective studies are needed to implement standardized clinical stratifications and risk-adapted therapeutic strategies.}, language = {en} } @article{FerreiraBoffVerzaetal.2021, author = {Ferreira, Eliana Aparecida and Boff, Samuel and Verza, Sandra S. and Mussury, Rosilda Mara}, title = {Bioecological and behavioral interaction between pollinating bees and the pioneer shrub Ludwigia nervosa in degraded area suggests an exotic bee as its major pollinator}, series = {Biology}, volume = {10}, journal = {Biology}, number = {2}, issn = {2079-7737}, doi = {10.3390/biology10020114}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228757}, year = {2021}, abstract = {The flowers of plants of the genus Ludwigia are an important source of food for several species of bees. In the current study, we conducted an experiment with the aim to describe the reproductive biology and phenology of L. nervosa; to identify the species of visiting bees; analyze the foraging behavior of bees; and to investigate whether the reproductive success of the species is related to the foraging activity of bees. We found that the flowers received visits from several native bee species (n = 7), in addition of the exotic honey bees which came to be the dominant species. During visits the majority of the bees foraged in both resources, pollen and nectar. The significantly higher production of fruits in open pollinated pollination experiment compared to artificial cross pollination, suggests honey bees as effective pollinator of this plant species in the study site. Pollen deposition occurs efficiently, given the absence of pollen limitation. Despite massive visitation of honey bees, Ludwigianervosa is attractive to native bees, and therefore it may help to sustain population of both native and exotic pollinators in fragmented humid areas.}, language = {en} } @article{BrosterReixFlorimondCayreletal.2021, author = {Broster Reix, Christine E. and Florimond, C{\´e}lia and Cayrel, Anne and Mailh{\´e}, Am{\´e}lie and Agnero-Rigot, Corentin and Landrein, Nicolas and Dacheux, Denis and Havlicek, Katharina and Bonhivers, M{\´e}lanie and Morriswood, Brooke and Robinson, Derrick R.}, title = {Bhalin, an essential cytoskeleton-associated protein of Trypanosoma brucei linking TbBILBO1 of the flagellar pocket collar with the hook complex}, series = {Microorganisms}, volume = {9}, journal = {Microorganisms}, number = {11}, issn = {2076-2607}, doi = {10.3390/microorganisms9112334}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250301}, year = {2021}, abstract = {Background: In most trypanosomes, endo and exocytosis only occur at a unique organelle called the flagellar pocket (FP) and the flagellum exits the cell via the FP. Investigations of essential cytoskeleton-associated structures located at this site have revealed a number of essential proteins. The protein TbBILBO1 is located at the neck of the FP in a structure called the flagellar pocket collar (FPC) and is essential for biogenesis of the FPC and parasite survival. TbMORN1 is a protein that is present on a closely linked structure called the hook complex (HC) and is located anterior to and overlapping the collar. TbMORN1 is essential in the bloodstream form of T. brucei. We now describe the location and function of BHALIN, an essential, new FPC-HC protein. Methodology/Principal Findings: Here, we show that a newly characterised protein, BHALIN (BILBO1 Hook Associated LINker protein), is localised to both the FPC and HC and has a TbBILBO1 binding domain, which was confirmed in vitro. Knockdown of BHALIN by RNAi in the bloodstream form parasites led to cell death, indicating an essential role in cell viability. Conclusions/Significance: Our results demonstrate the essential role of a newly characterised hook complex protein, BHALIN, that influences flagellar pocket organisation and function in bloodstream form T. brucei parasites.}, language = {en} } @article{UphusLuepkeYuanetal.2021, author = {Uphus, Lars and L{\"u}pke, Marvin and Yuan, Ye and Benjamin, Caryl and Englmeier, Jana and Fricke, Ute and Ganuza, Cristina and Schwindl, Michael and Uhler, Johannes and Menzel, Annette}, title = {Climate effects on vertical forest phenology of Fagus sylvatica L., sensed by Sentinel-2, time lapse camera, and visual ground observations}, series = {Remote Sensing}, volume = {13}, journal = {Remote Sensing}, number = {19}, issn = {2072-4292}, doi = {10.3390/rs13193982}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-248419}, year = {2021}, abstract = {Contemporary climate change leads to earlier spring phenological events in Europe. In forests, in which overstory strongly regulates the microclimate beneath, it is not clear if further change equally shifts the timing of leaf unfolding for the over- and understory of main deciduous forest species, such as Fagus sylvatica L. (European beech). Furthermore, it is not known yet how this vertical phenological (mis)match — the phenological difference between overstory and understory — affects the remotely sensed satellite signal. To investigate this, we disentangled the start of season (SOS) of overstory F.sylvatica foliage from understory F. sylvatica foliage in forests, within nine quadrants of 5.8 × 5.8 km, stratified over a temperature gradient of 2.5 °C in Bavaria, southeast Germany, in the spring seasons of 2019 and 2020 using time lapse cameras and visual ground observations. We explained SOS dates and vertical phenological (mis)match by canopy temperature and compared these to Sentinel-2 derived SOS in response to canopy temperature. We found that overstory SOS advanced with higher mean April canopy temperature (visual ground observations: -2.86 days per °C; cameras: -2.57 days per °C). However, understory SOS was not significantly affected by canopy temperature. This led to an increase of vertical phenological mismatch with increased canopy temperature (visual ground observations: +3.90 days per °C; cameras: +2.52 days per °C). These results matched Sentinel-2-derived SOS responses, as pixels of higher canopy height advanced more by increased canopy temperature than pixels of lower canopy height. The results may indicate that, with further climate change, spring phenology of F. sylvatica overstory will advance more than F. sylvatica understory, leading to increased vertical phenological mismatch in temperate deciduous forests. This may have major ecological effects, but also methodological consequences for the field of remote sensing, as what the signal senses highly depends on the pixel mean canopy height and the vertical (mis)match.}, language = {en} } @article{BerberichKurzReinhardetal.2021, author = {Berberich, Andreas and Kurz, Andreas and Reinhard, Sebastian and Paul, Torsten Johann and Burd, Paul Ray and Sauer, Markus and Kollmannsberger, Philip}, title = {Fourier Ring Correlation and anisotropic kernel density estimation improve deep learning based SMLM reconstruction of microtubules}, series = {Frontiers in Bioinformatics}, volume = {1}, journal = {Frontiers in Bioinformatics}, doi = {10.3389/fbinf.2021.752788}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261686}, year = {2021}, abstract = {Single-molecule super-resolution microscopy (SMLM) techniques like dSTORM can reveal biological structures down to the nanometer scale. The achievable resolution is not only defined by the localization precision of individual fluorescent molecules, but also by their density, which becomes a limiting factor e.g., in expansion microscopy. Artificial deep neural networks can learn to reconstruct dense super-resolved structures such as microtubules from a sparse, noisy set of data points. This approach requires a robust method to assess the quality of a predicted density image and to quantitatively compare it to a ground truth image. Such a quality measure needs to be differentiable to be applied as loss function in deep learning. We developed a new trainable quality measure based on Fourier Ring Correlation (FRC) and used it to train deep neural networks to map a small number of sampling points to an underlying density. Smooth ground truth images of microtubules were generated from localization coordinates using an anisotropic Gaussian kernel density estimator. We show that the FRC criterion ideally complements the existing state-of-the-art multiscale structural similarity index, since both are interpretable and there is no trade-off between them during optimization. The TensorFlow implementation of our FRC metric can easily be integrated into existing deep learning workflows.}, language = {en} } @article{AlnusaireSayedElmaidomyetal.2021, author = {Alnusaire, Taghreed S. and Sayed, Ahmed M. and Elmaidomy, Abeer H. and Al-Sanea, Mohammad M. and Albogami, Sarah and Albqmi, Mha and Alowaiesh, Bassam F. and Mostafa, Ehab M. and Musa, Arafa and Youssif, Khayrya A. and Refaat, Hesham and Othman, Eman M. and Dandekar, Thomas and Alaaeldin, Eman and Ghoneim, Mohammed M. and Abdelmohsen, Usama Ramadan}, title = {An in vitro and in silico study of the enhanced antiproliferative and pro-oxidant potential of Olea europaea L. cv. Arbosana leaf extract via elastic nanovesicles (spanlastics)}, series = {Antioxidants}, volume = {10}, journal = {Antioxidants}, number = {12}, issn = {2076-3921}, doi = {10.3390/antiox10121860}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250064}, year = {2021}, abstract = {The olive tree is a venerable Mediterranean plant and often used in traditional medicine. The main aim of the present study was to evaluate the effect of Olea europaea L. cv. Arbosana leaf extract (OLE) and its encapsulation within a spanlastic dosage form on the improvement of its pro-oxidant and antiproliferative activity against HepG-2, MCF-7, and Caco-2 human cancer cell lines. The LC-HRESIMS-assisted metabolomic profile of OLE putatively annotated 20 major metabolites and showed considerable in vitro antiproliferative activity against HepG-2, MCF-7, and Caco-2 cell lines with IC\(_{50}\) values of 9.2 ± 0.8, 7.1 ± 0.9, and 6.5 ± 0.7 µg/mL, respectively. The encapsulation of OLE within a (spanlastic) nanocarrier system, using a spraying method and Span 40 and Tween 80 (4:1 molar ratio), was successfully carried out (size 41 ± 2.4 nm, zeta potential 13.6 ± 2.5, and EE 61.43 ± 2.03\%). OLE showed enhanced thermal stability, and an improved in vitro antiproliferative effect against HepG-2, MCF-7, and Caco-2 (IC\(_{50}\) 3.6 ± 0.2, 2.3 ± 0.1, and 1.8 ± 0.1 µg/mL, respectively) in comparison to the unprocessed extract. Both preparations were found to exhibit pro-oxidant potential inside the cancer cells, through the potential inhibitory activity of OLE against glutathione reductase and superoxide dismutase (IC\(_{50}\) 1.18 ± 0.12 and 2.33 ± 0.19 µg/mL, respectively). These inhibitory activities were proposed via a comprehensive in silico study to be linked to the presence of certain compounds in OLE. Consequently, we assume that formulating such a herbal extract within a suitable nanocarrier would be a promising improvement of its therapeutic potential.}, language = {en} } @techreport{Dandekar2021, type = {Working Paper}, author = {Dandekar, Thomas}, title = {A new cosmology of a crystallization process (decoherence) from the surrounding quantum soup provides heuristics to unify general relativity and quantum physics by solid state physics}, doi = {10.25972/OPUS-23076}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230769}, pages = {42 Seiten}, year = {2021}, abstract = {We explore a cosmology where the Big Bang singularity is replaced by a condensation event of interacting strings. We study the transition from an uncontrolled, chaotic soup ("before") to a clearly interacting "real world". Cosmological inflation scenarios do not fit current observations and are avoided. Instead, long-range interactions inside this crystallization event limit growth and crystal symmetries ensure the same laws of nature and basic symmetries over our domain. Tiny mis-arrangements present nuclei of superclusters and galaxies and crystal structure leads to the arrangement of dark (halo regions) and normal matter (galaxy nuclei) so convenient for galaxy formation. Crystals come and go, allowing an evolutionary cosmology where entropic forces from the quantum soup "outside" of the crystal try to dissolve it. These would correspond to dark energy and leads to a big rip scenario in 70 Gy. Preference of crystals with optimal growth and most condensation nuclei for the next generation of crystals may select for multiple self-organizing processes within the crystal, explaining "fine-tuning" of the local "laws of nature" (the symmetry relations formed within the crystal, its "unit cell") to be particular favorable for self-organizing processes including life or even conscious observers in our universe. Independent of cosmology, a crystallization event may explain quantum-decoherence in general: The fact, that in our macroscopic everyday world we only see one reality. This contrasts strongly with the quantum world where you have coherence, a superposition of all quantum states. We suggest that a "real world" (so our everyday macroscopic world) happens only in our domain, i.e. inside a crystal. "Outside" of our domain and our observable universe there is the quantum soup of boiling quantum foam and superposition of all possibilities. In our crystallized world the vacuum no longer boils but is cooled down by the crystallization event and hence is 10**20 smaller, exactly as observed in our everyday world. As we live in a "solid" state, within a crystal, the different quanta which build our world have all their different states nicely separated. This theory postulates there are only n quanta and m states available for them (there is no Everett-like ever splitting multiverse after each decision). In the solid state we live in, there is decoherence, the states are nicely separated. The arrow of entropy for each edge of the crystal forms one fate, one worldline or clear development of a world, while the layers of the crystal are different system states. Some mathematical leads from loop quantum gravity point to required interactions and potentials. A complete mathematical treatment of this unified theory is far too demanding currently. Interaction potentials for strings or membranes of any dimension allow a solid state of quanta, so allowing decoherence in our observed world are challenging to calculate. However, if we introduce here the heuristic that any type of physical interaction of strings corresponds just to a type of calculation, there is already since 1898 the Hurwitz theorem showing that then only 1D, 2D, 4D and 8D (octonions) allow complex or hypercomplex number calculations. No other hypercomplex numbers and hence dimensions or symmetries are possible to allow calculations without yielding divisions by zero. However, the richest solution allowed by the Hurwitz theorem, octonions, is actually the observed symmetry of our universe, E8.  }, subject = {Kosmologie}, language = {en} } @article{LinkBorgesJonesetal.2021, author = {Link, Fabian and Borges, Alyssa R. and Jones, Nicola G. and Engstler, Markus}, title = {To the Surface and Back: Exo- and Endocytic Pathways in Trypanosoma brucei}, series = {Frontiers in Cell and Developmental Biology}, volume = {9}, journal = {Frontiers in Cell and Developmental Biology}, issn = {2296-634X}, doi = {10.3389/fcell.2021.720521}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244682}, year = {2021}, abstract = {Trypanosoma brucei is one of only a few unicellular pathogens that thrives extracellularly in the vertebrate host. Consequently, the cell surface plays a critical role in both immune recognition and immune evasion. The variant surface glycoprotein (VSG) coats the entire surface of the parasite and acts as a flexible shield to protect invariant proteins against immune recognition. Antigenic variation of the VSG coat is the major virulence mechanism of trypanosomes. In addition, incessant motility of the parasite contributes to its immune evasion, as the resulting fluid flow on the cell surface drags immunocomplexes toward the flagellar pocket, where they are internalized. The flagellar pocket is the sole site of endo- and exocytosis in this organism. After internalization, VSG is rapidly recycled back to the surface, whereas host antibodies are thought to be transported to the lysosome for degradation. For this essential step to work, effective machineries for both sorting and recycling of VSGs must have evolved in trypanosomes. Our understanding of the mechanisms behind VSG recycling and VSG secretion, is by far not complete. This review provides an overview of the trypanosome secretory and endosomal pathways. Longstanding questions are pinpointed that, with the advent of novel technologies, might be answered in the near future.}, language = {en} } @article{PanzerZhangKonteetal.2021, author = {Panzer, Sabine and Zhang, Chong and Konte, Tilen and Br{\"a}uer, Celine and Diemar, Anne and Yogendran, Parathy and Yu-Strzelczyk, Jing and Nagel, Georg and Gao, Shiqiang and Terpitz, Ulrich}, title = {Modified Rhodopsins From Aureobasidium pullulans Excel With Very High Proton-Transport Rates}, series = {Frontiers in Molecular Biosciences}, volume = {8}, journal = {Frontiers in Molecular Biosciences}, issn = {2296-889X}, doi = {10.3389/fmolb.2021.750528}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249248}, year = {2021}, abstract = {Aureobasidium pullulans is a black fungus that can adapt to various stressful conditions like hypersaline, acidic, and alkaline environments. The genome of A. pullulans exhibits three genes coding for putative opsins ApOps1, ApOps2, and ApOps3. We heterologously expressed these genes in mammalian cells and Xenopus oocytes. Localization in the plasma membrane was greatly improved by introducing additional membrane trafficking signals at the N-terminus and the C-terminus. In patch-clamp and two-electrode-voltage clamp experiments, all three proteins showed proton pump activity with maximal activity in green light. Among them, ApOps2 exhibited the most pronounced proton pump activity with current amplitudes occasionally extending 10 pA/pF at 0 mV. Proton pump activity was further supported in the presence of extracellular weak organic acids. Furthermore, we used site-directed mutagenesis to reshape protein functions and thereby implemented light-gated proton channels. We discuss the difference to other well-known proton pumps and the potential of these rhodopsins for optogenetic applications.}, language = {en} } @article{VogelPrinzingBussleretal.2021, author = {Vogel, Sebastian and Prinzing, Andreas and Bußler, Heinz and M{\"u}ller, J{\"o}rg and Schmidt, Stefan and Thorn, Simon}, title = {Abundance, not diversity, of host beetle communities determines abundance and diversity of parasitoids in deadwood}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {11}, doi = {10.1002/ece3.7535}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238892}, pages = {6881 -- 6888}, year = {2021}, abstract = {Most parasites and parasitoids are adapted to overcome defense mechanisms of their specific hosts and hence colonize a narrow range of host species. Accordingly, an increase in host functional or phylogenetic dissimilarity is expected to increase the species diversity of parasitoids. However, the local diversity of parasitoids may be driven by the accessibility and detectability of hosts, both increasing with increasing host abundance. Yet, the relative importance of these two mechanisms remains unclear. We parallelly reared communities of saproxylic beetle as potential hosts and associated parasitoid Hymenoptera from experimentally felled trees. The dissimilarity of beetle communities was inferred from distances in seven functional traits and from their evolutionary ancestry. We tested the effect of host abundance, species richness, functional, and phylogenetic dissimilarities on the abundance, species richness, and Shannon diversity of parasitoids. Our results showed an increase of abundance, species richness, and Shannon diversity of parasitoids with increasing beetle abundance. Additionally, abundance of parasitoids increased with increasing species richness of beetles. However, functional and phylogenetic dissimilarity showed no effect on the diversity of parasitoids. Our results suggest that the local diversity of parasitoids, of ephemeral and hidden resources like saproxylic beetles, is highest when resources are abundant and thereby detectable and accessible. Hence, in some cases, resources do not need to be diverse to promote parasitoid diversity.}, language = {en} } @article{MakbulKraftGriessmannetal.2021, author = {Makbul, Cihan and Kraft, Christian and Grießmann, Matthias and Rasmussen, Tim and Katzenberger, Kilian and Lappe, Melina and Pfarr, Paul and Stoffer, Cato and St{\"o}hr, Mara and Wandinger, Anna-Maria and B{\"o}ttcher, Bettina}, title = {Binding of a pocket factor to Hepatitis B virus capsids changes the rotamer conformation of Phenylalanine 97}, series = {Viruses}, volume = {13}, journal = {Viruses}, number = {11}, issn = {1999-4915}, doi = {10.3390/v13112115}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-248565}, year = {2021}, abstract = {(1) Background: During maturation of the Hepatitis B virus, a viral polymerase inside the capsid transcribes a pre-genomic RNA into a partly double stranded DNA-genome. This is followed by envelopment with surface proteins inserted into a membrane. Envelopment is hypothetically regulated by a structural signal that reports the maturation state of the genome. NMR data suggest that such a signal can be mimicked by the binding of the detergent Triton X 100 to hydrophobic pockets in the capsid spikes. (2) Methods: We have used electron cryo-microscopy and image processing to elucidate the structural changes that are concomitant with the binding of Triton X 100. (3) Results: Our maps show that Triton X 100 binds with its hydrophobic head group inside the pocket. The hydrophilic tail delineates the outside of the spike and is coordinated via Lys-96. The binding of Triton X 100 changes the rotamer conformation of Phe-97 in helix 4, which enables a π-stacking interaction with Trp-62 in helix 3. Similar changes occur in mutants with low secretion phenotypes (P5T and L60V) and in a mutant with a pre-mature secretion phenotype (F97L). (4) Conclusion: Binding of Triton X 100 is unlikely to mimic structural maturation because mutants with different secretion phenotypes show similar structural responses.}, language = {en} } @article{JanschZieglerForeroetal.2021, author = {Jansch, Charline and Ziegler, Georg C. and Forero, Andrea and Gredy, Sina and W{\"a}ldchen, Sina and Vitale, Maria Rosaria and Svirin, Evgeniy and Z{\"o}ller, Johanna E. M. and Waider, Jonas and G{\"u}nther, Katharina and Edenhofer, Frank and Sauer, Markus and Wischmeyer, Erhard and Lesch, Klaus-Peter}, title = {Serotonin-specific neurons differentiated from human iPSCs form distinct subtypes with synaptic protein assembly}, series = {Journal of Neural Transmission}, volume = {128}, journal = {Journal of Neural Transmission}, number = {2}, issn = {1435-1463}, doi = {10.1007/s00702-021-02303-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268519}, pages = {225-241}, year = {2021}, abstract = {Human induced pluripotent stem cells (hiPSCs) have revolutionized the generation of experimental disease models, but the development of protocols for the differentiation of functionally active neuronal subtypes with defined specification is still in its infancy. While dysfunction of the brain serotonin (5-HT) system has been implicated in the etiology of various neuropsychiatric disorders, investigation of functional human 5-HT specific neurons in vitro has been restricted by technical limitations. We describe an efficient generation of functionally active neurons from hiPSCs displaying 5-HT specification by modification of a previously reported protocol. Furthermore, 5-HT specific neurons were characterized using high-end fluorescence imaging including super-resolution microscopy in combination with electrophysiological techniques. Differentiated hiPSCs synthesize 5-HT, express specific markers, such as tryptophan hydroxylase 2 and 5-HT transporter, and exhibit an electrophysiological signature characteristic of serotonergic neurons, with spontaneous rhythmic activities, broad action potentials and large afterhyperpolarization potentials. 5-HT specific neurons form synapses reflected by the expression of pre- and postsynaptic proteins, such as Bassoon and Homer. The distribution pattern of Bassoon, a marker of the active zone along the soma and extensions of neurons, indicates functionality via volume transmission. Among the high percentage of 5-HT specific neurons (~ 42\%), a subpopulation of CDH13 + cells presumably designates dorsal raphe neurons. hiPSC-derived 5-HT specific neuronal cell cultures reflect the heterogeneous nature of dorsal and median raphe nuclei and may facilitate examining the association of serotonergic neuron subpopulations with neuropsychiatric disorders.}, language = {en} } @article{KronesRuehlingBeckeretal.2021, author = {Krones, David and R{\"u}hling, Marcel and Becker, Katrin Anne and Kunz, Tobias C. and Sehl, Carolin and Paprotka, Kerstin and Gulbins, Erich and Fraunholz, Martin}, title = {Staphylococcus aureus α-Toxin Induces Acid Sphingomyelinase Release From a Human Endothelial Cell Line}, series = {Frontiers in Microbiology}, volume = {12}, journal = {Frontiers in Microbiology}, issn = {1664-302X}, doi = {10.3389/fmicb.2021.694489}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244843}, year = {2021}, abstract = {Staphylococcus aureus (S. aureus) is well known to express a plethora of toxins of which the pore-forming hemolysin A (α-toxin) is the best-studied cytolysin. Pore-forming toxins (PFT) permeabilize host membranes during infection thereby causing concentration-dependent effects in host cell membranes ranging from disordered ion fluxes to cytolysis. Host cells possess defense mechanisms against PFT attack, resulting in endocytosis of the breached membrane area and delivery of repair vesicles to the insulted plasma membrane as well as a concurrent release of membrane repair enzymes. Since PFTs from several pathogens have been shown to recruit membrane repair components, we here investigated whether staphylococcal α-toxin is able to induce these mechanisms in endothelial cells. We show that S. aureus α-toxin induced increase in cytosolic Ca2+ in endothelial cells, which was accompanied by p38 MAPK phosphorylation. Toxin challenge led to increased endocytosis of an extracellular fluid phase marker as well as increased externalization of LAMP1-positive membranes suggesting that peripheral lysosomes are recruited to the insulted plasma membrane. We further observed that thereby the lysosomal protein acid sphingomyelinase (ASM) was released into the cell culture medium. Thus, our results show that staphylococcal α-toxin triggers mechanisms in endothelial cells, which have been implicated in membrane repair after damage of other cell types by different toxins.}, language = {en} } @phdthesis{Andreska2021, author = {Andreska, Thomas}, title = {Effects of dopamine on BDNF / TrkB mediated signaling and plasticity on cortico-striatal synapses}, doi = {10.25972/OPUS-17431}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174317}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Progressive loss of voluntary movement control is the central symptom of Parkinson's disease (PD). Even today, we are not yet able to cure PD. This is mainly due to a lack of understanding the mechanisms of movement control, network activity and plasticity in motor circuits, in particular between the cerebral cortex and the striatum. Brain-derived neurotrophic factor (BDNF) has emerged as one of the most important factors for the development and survival of neurons, as well as for synaptic plasticity. It is thus an important target for the development of new therapeutic strategies against neurodegenerative diseases. Together with its receptor, the Tropomyosin receptor kinase B (TrkB), it is critically involved in development and function of the striatum. Nevertheless, little is known about the localization of BDNF within presynaptic terminals in the striatum, as well as the types of neurons that produce BDNF in the cerebral cortex. Furthermore, the influence of midbrain derived dopamine on the control of BDNF / TrkB interaction in striatal medium spiny neurons (MSNs) remains elusive so far. Dopamine, however, appears to play an important role, as its absence leads to drastic changes in striatal synaptic plasticity. This suggests that dopamine could regulate synaptic activity in the striatum via modulation of BDNF / TrkB function. To answer these questions, we have developed a sensitive and reliable protocol for the immunohistochemical detection of endogenous BDNF. We find that the majority of striatal BDNF is provided by glutamatergic, cortex derived afferents and not dopaminergic inputs from the midbrain. In fact, we found BDNF in cell bodies of neurons in layers II-III and V of the primary and secondary motor cortex as well as layer V of the somatosensory cortex. These are the brain areas that send dense projections to the dorsolateral striatum for control of voluntary movement. Furthermore, we could show that these projection neurons significantly downregulate the expression of BDNF during the juvenile development of mice between 3 and 12 weeks. In parallel, we found a modulatory effect of dopamine on the translocation of TrkB to the cell surface in postsynaptic striatal Medium Spiny Neurons (MSNs). In MSNs of the direct pathway (dMSNs), which express dopamine receptor 1 (DRD1), we observed the formation of TrkB aggregates in the 6-hydroxydopamine (6-OHDA) model of PD. This suggests that DRD1 activity controls TrkB surface expression in these neurons. In contrast, we found that DRD2 activation has opposite effects in MSNs of the indirect pathway (iMSNs). Activation of DRD2 promotes a rapid decrease in TrkB surface expression which was reversible and depended on cAMP. In parallel, stimulation of DRD2 led to induction of phospho-TrkB (pTrkB). This effect was significantly slower than the effect on TrkB surface expression and indicates that TrkB is transactivated by DRD2. Together, our data provide evidence that dopamine triggers dual modes of plasticity on striatal MSNs by acting on TrkB surface expression in DRD1 and DRD2 expressing MSNs. This surface expression of the receptor is crucial for the binding of BDNF, which is released from corticostriatal afferents. This leads to the induction of TrkB-mediated downstream signal transduction cascades and long-term potentiation (LTP). Therefore, the dopamine-mediated translocation of TrkB could be a mediator that modulates the balance between dopaminergic and glutamatergic signaling to allow synaptic plasticity in a spatiotemporal manner. This information and the fact that TrkB is segregated to persistent aggregates in PD could help to improve our understanding of voluntary movement control and to develop new therapeutic strategies beyond those focusing on dopaminergic supply.}, subject = {Brain-derived neurotrophic factor}, language = {en} } @article{PuetzKramRauhetal.2021, author = {P{\"u}tz, Stephanie M. and Kram, Jette and Rauh, Elisa and Kaiser, Sophie and Toews, Romy and Lueningschroer-Wang, Yi and Rieger, Dirk and Raabe, Thomas}, title = {Loss of p21-activated kinase Mbt/PAK4 causes Parkinson-like symptoms in Drosophila}, series = {Disease Models \& Mechanisms}, volume = {14}, journal = {Disease Models \& Mechanisms}, number = {6}, doi = {10.1242/dmm.047811}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259222}, pages = {dmm047811}, year = {2021}, abstract = {Parkinson's disease (PD) provokes bradykinesia, resting tremor, rigidity and postural instability, and also non-motor symptoms such as depression, anxiety, sleep and cognitive impairments. Similar phenotypes can be induced in Drosophila melanogaster through modification of PD-relevant genes or the administration of PD inducing toxins. Recent studies correlated deregulation of human p21-activated kinase 4 (PAK4) with PD, leaving open the question of a causative relationship of mutations in this gene for manifestation of PD symptoms. To determine whether flies lacking the PAK4 homolog Mushroom bodies tiny (Mbt) show PD-like phenotypes, we tested for a variety of PD criteria. Here, we demonstrate that mbt mutant flies show PD-like phenotypes including age-dependent movement deficits, reduced life expectancy and fragmented sleep. They also react to a stressful situation with higher immobility, indicating an influence of Mbt on emotional behavior. Loss of Mbt function has a negative effect on the number of dopaminergic protocerebral anterior medial (PAM) neurons, most likely caused by a proliferation defect of neural progenitors. The age-dependent movement deficits are not accompanied by a corresponding further loss of PAM neurons. Previous studies highlighted the importance of a small PAM subgroup for age-dependent PD motor impairments. We show that impaired motor skills are caused by a lack of Mbt in this PAM subgroup. In addition, a broader re-expression of Mbt in PAM neurons improves life expectancy. Conversely, selective Mbt knockout in the same cells shortens lifespan. We conclude that mutations in Mbt/PAK4 can play a causative role in the development of PD phenotypes.}, language = {en} } @article{HeidrichPinkertBrandletal.2021, author = {Heidrich, Lea and Pinkert, Stefan and Brandl, Roland and B{\"a}ssler, Claus and Hacker, Hermann and Roth, Nicolas and Busse, Annika and M{\"u}ller, J{\"o}rg and Friess, Nicolas}, title = {Noctuid and geometrid moth assemblages show divergent elevational gradients in body size and color lightness}, series = {Ecography}, volume = {44}, journal = {Ecography}, number = {8}, doi = {10.1111/ecog.05558}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256694}, pages = {1169-1179}, year = {2021}, abstract = {Previous macroecological studies have suggested that larger and darker insects are favored in cold environments and that the importance of body size and color for the absorption of solar radiation is not limited to diurnal insects. However, whether these effects hold true for local communities and are consistent across taxonomic groups and sampling years remains unexplored. This study examined the variations in body size and color lightness of the two major families of nocturnal moths, Geometridae and Noctuidae, along an elevational gradient of 700 m in Southern Germany. An assemblage-based analysis was performed using community-weighted means and a fourth-corner analysis to test for variations in color and body size among communities as a function of elevation. This was followed by a species-level analysis to test whether species occurrence and abundance along an elevation gradient were related to these traits, after controlling for host plant availability. In both 2007 and 2016, noctuid moth assemblages became larger and darker with increasing elevation, whereas geometrids showed an opposite trend in terms of color lightness and no clear trend in body size. In single species models, the abundance of geometrids, but not of noctuids, was driven by habitat availability. In turn, the abundance of dark-colored noctuids, but not geometrids increased with elevation. While body size and color lightness affect insect physiology and the ability to cope with harsh conditions, divergent trait-environment relationships between both families underline that findings of coarse-scale studies are not necessarily transferable to finer scales. Local abundance and occurrence of noctuids are shaped by morphological traits, whereas that of geometrids are rather shaped by local habitat availability, which can modify their trait-environment-relationship. We discuss potential explanations such as taxon-specific flight characteristics and the effect of microclimatic conditions.}, language = {en} } @phdthesis{Groma2021, author = {Groma, Michaela}, title = {Identification of a novel LysR-type transcriptional regulator in \(Staphylococcus\) \(aureus\)}, doi = {10.25972/OPUS-24675}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Staphylococcus aureus is a facultative pathogen which causes a variety of infections. The treatment of staphylococcal infections is complicated because the bacteria is resistant to multiple common antibiotics. S. aureus is also known to express a variety of virulence factors which modulate the host's immune response in order to colonize and invade certain host cells, leading to the host cell's death. Among the virulence factors is a LysR-type transcriptional regulator (lttr) which is required for efficient colonization of secondary organs. In a recent report, which used transposon screening on S. aureus-infected mice, it was found that the amount of a novel lttr852 mutant bacteria recovered from the kidneys was significantly lower compared to the wildtype strains. This doctoral thesis therefore focused on phenotypical and molecular characterization of lttr852. An assessment of the S. aureus biofilm formation and the hemolysis revealed that lttr852 was not involved in the regulation of these virulence processes. RNA-sequencing for potential target genes of lttr852 identified differentially expressed genes that are involved in branched chain amino-acid biosynthesis, methionine sulfoxide reductase and copper transport, as well as a reduced transcription of genes encoding urease and of components of pyrimidine nucleotides. Promoter fusion with GFP reporters as as well as OmniLog were used to identify conditions under which the lttr852 was active. The promoter studies showed that glucose and high temperatures diminish the lttr852 promoter activity in a time-dependent manner, while micro-aerobic conditions enhanced the promoter activity. Copper was found to be a limiting factor. In addition, the impact on promoter activity of the lttr852 was tested in the presence of various regulators, but no central link to the genes involved in virulence was identified. The present work, thus, showed that lttr852, a new member of the class of LysR-type transcriptional regulators in S. aureus, has an important role in the rapid adaptation of S. aureus to the changing microenvironment of the host.}, language = {en} } @article{GaritanoTrojaolaSanchoGoetzetal.2021, author = {Garitano-Trojaola, Andoni and Sancho, Ana and G{\"o}tz, Ralph and Eiring, Patrick and Walz, Susanne and Jetani, Hardikkumar and Gil-Pulido, Jesus and Da Via, Matteo Claudio and Teufel, Eva and Rhodes, Nadine and Haertle, Larissa and Arellano-Viera, Estibaliz and Tibes, Raoul and Rosenwald, Andreas and Rasche, Leo and Hudecek, Michael and Sauer, Markus and Groll, J{\"u}rgen and Einsele, Hermann and Kraus, Sabrina and Kort{\"u}m, Martin K.}, title = {Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia}, series = {Communications Biology}, volume = {4}, journal = {Communications Biology}, number = {1}, doi = {10.1038/s42003-021-02215-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260709}, year = {2021}, abstract = {The presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD+AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD+AML. Garitano-Trojaola et al. used a combination of human acute myeloid leukemia (AML) cell lines and primary samples to show that RAC1-dependent actin cytoskeleton remodeling through BCL2 family plays a key role in resistance to the FLT3 inhibitor, Midostaurin in AML. They showed that by targeting RAC1 and BCL2, Midostaurin resistance was diminished, which potentially paves the way for an innovate treatment approach for FLT3 mutant AML.}, language = {en} } @article{CastanedaLondonoBanholzerBannermannetal.2021, author = {Casta{\~n}eda Londono, Paula Andrea and Banholzer, Nicole and Bannermann, Bridget and Kramer, Susanne}, title = {Is mRNA decapping activity of ApaH like phosphatases (ALPH's) the reason for the loss of cytoplasmic ALPH's in all eukaryotes but Kinetoplastida?}, series = {BMC Ecology and Evolution}, volume = {21}, journal = {BMC Ecology and Evolution}, doi = {10.1186/s12862-021-01858-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261180}, year = {2021}, abstract = {Background: ApaH like phosphatases (ALPHs) originate from the bacterial ApaH protein and are present in eukaryotes of all eukaryotic super-groups; still, only two proteins have been functionally characterised. One is ALPH1 from the Kinetoplastid Trypanosoma brucei that we recently found to be the mRNA decapping enzyme of the parasite. mRNA decapping by ALPHs is unprecedented in eukaryotes, which usually use nudix hydrolases, but the bacterial ancestor protein ApaH was recently found to decap non-conventional caps of bacterial mRNAs. These findings prompted us to explore whether mRNA decapping by ALPHs is restricted to Kinetoplastida or more widespread among eukaryotes. Results: We screened 824 eukaryotic proteomes with a newly developed Python-based algorithm for the presence of ALPHs and used the data to refine phylogenetic distribution, conserved features, additional domains and predicted intracellular localisation of ALPHs. We found that most eukaryotes have either no ALPH (500/824) or very short ALPHs, consisting almost exclusively of the catalytic domain. These ALPHs had mostly predicted non-cytoplasmic localisations, often supported by the presence of transmembrane helices and signal peptides and in two cases (one in this study) by experimental data. The only exceptions were ALPH1 homologues from Kinetoplastida, that all have unique C-terminal and mostly unique N-terminal extension, and at least the T. brucei enzyme localises to the cytoplasm. Surprisingly, despite of these non-cytoplasmic localisations, ALPHs from all eukaryotic super-groups had in vitro mRNA decapping activity. Conclusions: ALPH was present in the last common ancestor of eukaryotes, but most eukaryotes have either lost the enzyme since, or use it exclusively outside the cytoplasm in organelles in a version consisting of the catalytic domain only. While our data provide no evidence for the presence of further mRNA decapping enzymes among eukaryotic ALPHs, the broad substrate range of ALPHs that includes mRNA caps provides an explanation for the selection against the presence of a cytoplasmic ALPH protein as a mean to protect mRNAs from unregulated degradation. Kinetoplastida succeeded to exploit ALPH as their mRNA decapping enzyme, likely using the Kinetoplastida-unique N- and C-terminal extensions for regulation.}, language = {en} } @phdthesis{Mayr2021, author = {Mayr, Antonia Veronika}, title = {Following Bees and Wasps up Mt. Kilimanjaro: From Diversity and Traits to hidden Interactions of Species}, doi = {10.25972/OPUS-18292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-182922}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Chapter 1 - General Introduction One of the greatest challenges of ecological research is to predict the response of ecosystems to global change; that is to changes in climate and land use. A complex question in this context is how changing environmental conditions affect ecosystem processes at different levels of communities. To shed light on this issue, I investigate drivers of biodiversity on the level of species richness, functional traits and species interactions in cavity-nesting Hymenoptera. For this purpose, I take advantage of the steep elevational gradient of Mt. Kilimanjaro that shows strong environmental changes on a relatively small spatial scale and thus, provides a good environmental scenario for investigating drivers of diversity. In this thesis, I focus on 1) drivers of species richness at different trophic levels (Chapter 2); 2) seasonal patterns in nest-building activity, life-history traits and ecological rates in three different functional groups and at different elevations (Chapter 3) and 3) changes in cuticular hydrocarbons, pollen composition and microbiomes in Lasioglossum bees caused by climatic variables (Chapter 4). Chapter 2 - Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera Drivers of species richness have been subject to research for centuries. Temperature, resource availability and top-down regulation as well as the impact of land use are considered to be important factors in determining insect diversity. Yet, the relative importance of each of these factors is unknown. Using trap nests along the elevational gradient of Mt. Kilimanjaro, we tried to disentangle drivers of species richness at different trophic levels. Temperature was the major driver of species richness across trophic levels, with increasing importance of food resources at higher trophic levels in natural antagonists. Parasitism rate was both related to temperature and trophic level, indicating that the relative importance of bottom-up and top-down forces might shift with climate change. Chapter 3 - Seasonal variation in the ecology of tropical cavity-nesting Hymenoptera Natural populations fluctuate with the availability of resources, presence of natural enemies and climatic variations. But tropical mountain seasonality is not yet well investigated. We investigated seasonal patterns in nest-building activity, functional traits and ecological rates in three different insect groups at lower and higher elevations separately. Insects were caught with trap nests which were checked monthly during a 17 months period that included three dry and three rainy seasons. Insects were grouped according to their functional guilds. All groups showed strong seasonality in nest-building activity which was higher and more synchronised among groups at lower elevations. Seasonality in nest building activity of caterpillar-hunting and spider-hunting wasps was linked to climate seasonality while in bees it was strongly linked to the availability of flowers, as well as for the survival rate and sex ratio of bees. Finding adaptations to environmental seasonality might imply that further changes in climatic seasonality by climate change could have an influence on life-history traits of tropical mountain species. Chapter 4 - Cryptic species and hidden ecological interactions of halictine bees along an elevational Gradient Strong environmental gradients such as those occurring along mountain slopes are challenging for species. In this context, hidden adaptations or interactions have rarely been considered. We used bees of the genus Lasioglossum as model organisms because Lasioglossum is the only bee genus occurring with a distribution across the entire elevational gradient at Mt. Kilimanjaro. We asked if and how (a) cuticular hydrocarbons (CHC), which act as a desiccation barrier, change in composition and chain length along with changes in temperature and humidity (b), Lasioglossum bees change their pollen diet with changing resource availability, (c) gut microbiota change with pollen diet and climatic conditions, and surface microbiota change with CHC and climatic conditions, respectively, and if changes are rather influenced by turnover in Lasioglossum species along the elevational gradient. We found physiological adaptations with climate in CHC as well as changes in communities with regard to pollen diet and microbiota, which also correlated with each other. These results suggest that complex interactions and feedbacks among abiotic and biotic conditions determine the species composition in a community. Chapter 5 - General Discussion Abiotic and biotic factors drove species diversity, traits and interactions and they worked differently depending on the functional group that has been studied, and whether spatial or temporal units were considered. It is therefore likely, that in the light of global change, different species, traits and interactions will be affected differently. Furthermore, increasing land use intensity could have additional or interacting effects with climate change on biodiversity, even though the potential land-use effects at Mt. Kilimanjaro are still low and not impairing cavity-nesting Hymenoptera so far. Further studies should address species networks which might reveal more sensitive changes. For that purpose, trap nests provide a good model system to investigate effects of global change on multiple trophic levels and may also reveal direct effects of climate change on entire life-history traits when established under different microclimatic conditions. The non-uniform effects of abiotic and biotic conditions on multiple aspects of biodiversity revealed with this study also highlight that evaluating different aspects of biodiversity can give a more comprehensive picture than single observations.}, subject = {land use}, language = {en} } @article{MrestaniPauliKollmannsbergeretal.2021, author = {Mrestani, Achmed and Pauli, Martin and Kollmannsberger, Philip and Repp, Felix and Kittel, Robert J. and Eilers, Jens and Doose, S{\"o}ren and Sauer, Markus and Sir{\´e}n, Anna-Leena and Heckmann, Manfred and Paul, Mila M.}, title = {Active zone compaction correlates with presynaptic homeostatic potentiation}, series = {Cell Reports}, volume = {37}, journal = {Cell Reports}, number = {1}, doi = {10.1016/j.celrep.2021.109770}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265497}, pages = {109770}, year = {2021}, abstract = {Neurotransmitter release is stabilized by homeostatic plasticity. Presynaptic homeostatic potentiation (PHP) operates on timescales ranging from minute- to life-long adaptations and likely involves reorganization of presynaptic active zones (AZs). At Drosophila melanogaster neuromuscular junctions, earlier work ascribed AZ enlargement by incorporating more Bruchpilot (Brp) scaffold protein a role in PHP. We use localization microscopy (direct stochastic optical reconstruction microscopy [dSTORM]) and hierarchical density-based spatial clustering of applications with noise (HDBSCAN) to study AZ plasticity during PHP at the synaptic mesoscale. We find compaction of individual AZs in acute philanthotoxin-induced and chronic genetically induced PHP but unchanged copy numbers of AZ proteins. Compaction even occurs at the level of Brp subclusters, which move toward AZ centers, and in Rab3 interacting molecule (RIM)-binding protein (RBP) subclusters. Furthermore, correlative confocal and dSTORM imaging reveals how AZ compaction in PHP translates into apparent increases in AZ area and Brp protein content, as implied earlier.}, language = {en} } @unpublished{HennigPrustyKauferetal.2021, author = {Hennig, Thomas and Prusty, Archana B. and Kaufer, Benedikt and Whisnant, Adam W. and Lodha, Manivel and Enders, Antje and Thomas, Julius and Kasimir, Francesca and Grothey, Arnhild and Herb, Stefanie and J{\"u}rges, Christopher and Meister, Gunter and Erhard, Florian and D{\"o}lken, Lars and Prusty, Bhupesh K.}, title = {Selective inhibition of microRNA processing by a herpesvirus-encoded microRNA triggers virus reactivation from latency}, edition = {submitted version}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267858}, year = {2021}, abstract = {Herpesviruses have mastered host cell modulation and immune evasion to augment productive infection, life-long latency and reactivation thereof 1,2. A long appreciated, yet elusively defined relationship exists between the lytic-latent switch and viral non-coding RNAs 3,4. Here, we identify miRNA-mediated inhibition of miRNA processing as a novel cellular mechanism that human herpesvirus 6A (HHV-6A) exploits to disrupt mitochondrial architecture, evade intrinsic host defense and drive the latent-lytic switch. We demonstrate that virus-encoded miR-aU14 selectively inhibits the processing of multiple miR-30 family members by direct interaction with the respective pri-miRNA hairpin loops. Subsequent loss of miR-30 and activation of miR-30/p53/Drp1 axis triggers a profound disruption of mitochondrial architecture, which impairs induction of type I interferons and is necessary for both productive infection and virus reactivation. Ectopic expression of miR-aU14 was sufficient to trigger virus reactivation from latency thereby identifying it as a readily drugable master regulator of the herpesvirus latent-lytic switch. Our results show that miRNA-mediated inhibition of miRNA processing represents a generalized cellular mechanism that can be exploited to selectively target individual members of miRNA families. We anticipate that targeting miR-aU14 provides exciting therapeutic options for preventing herpesvirus reactivations in HHV-6-associated disorders like myalgic encephalitis/chronic fatigue syndrome (ME/CFS) and Long-COVID.}, language = {en} } @article{LehenbergerBenkertBiedermann2021, author = {Lehenberger, Maximilian and Benkert, Markus and Biedermann, Peter H. W.}, title = {Ethanol-Enriched Substrate Facilitates Ambrosia Beetle Fungi, but Inhibits Their Pathogens and Fungal Symbionts of Bark Beetles}, series = {Frontiers in Microbiology}, volume = {11}, journal = {Frontiers in Microbiology}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.590111}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222222}, year = {2021}, abstract = {Bark beetles (sensu lato) colonize woody tissues like phloem or xylem and are associated with a broad range of micro-organisms. Specific fungi in the ascomycete orders Hypocreales, Microascales and Ophistomatales as well as the basidiomycete Russulales have been found to be of high importance for successful tree colonization and reproduction in many species. While fungal mutualisms are facultative for most phloem-colonizing bark beetles (sensu stricto), xylem-colonizing ambrosia beetles are long known to obligatorily depend on mutualistic fungi for nutrition of adults and larvae. Recently, a defensive role of fungal mutualists for their ambrosia beetle hosts was revealed: Few tested mutualists outcompeted other beetle-antagonistic fungi by their ability to produce, detoxify and metabolize ethanol, which is naturally occurring in stressed and/or dying trees that many ambrosia beetle species preferentially colonize. Here, we aim to test (i) how widespread beneficial effects of ethanol are among the independently evolved lineages of ambrosia beetle fungal mutualists and (ii) whether it is also present in common fungal symbionts of two bark beetle species (Ips typographus, Dendroctonus ponderosae) and some general fungal antagonists of bark and ambrosia beetle species. The majority of mutualistic ambrosia beetle fungi tested benefited (or at least were not harmed) by the presence of ethanol in terms of growth parameters (e.g., biomass), whereas fungal antagonists were inhibited. This confirms the competitive advantage of nutritional mutualists in the beetle's preferred, ethanol-containing host material. Even though most bark beetle fungi are found in the same phylogenetic lineages and ancestral to the ambrosia beetle (sensu stricto) fungi, most of them were highly negatively affected by ethanol and only a nutritional mutualist of Dendroctonus ponderosae benefited, however. This suggests that ethanol tolerance is a derived trait in nutritional fungal mutualists, particularly in ambrosia beetles that show cooperative farming of their fungi.}, language = {en} } @article{SchusterLisackSubotaetal.2021, author = {Schuster, Sarah and Lisack, Jaime and Subota, Ines and Zimmermann, Henriette and Reuter, Christian and Mueller, Tobias and Morriswood, Brooke and Engstler, Markus}, title = {Unexpected plasiticty in the life cycle of Trypanosoma brucei}, series = {eLife}, volume = {10}, journal = {eLife}, doi = {10.7554/eLife.66028.sa2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261744}, year = {2021}, abstract = {African trypanosomes cause sleeping sickness in humans and nagana in cattle. These unicellular parasites are transmitted by the bloodsucking tsetse fly. In the mammalian host's circulation, proliferating slender stage cells differentiate into cell cycle-arrested stumpy stage cells when they reach high population densities. This stage transition is thought to fulfil two main functions: first, it auto-regulates the parasite load in the host; second, the stumpy stage is regarded as the only stage capable of successful vector transmission. Here, we show that proliferating slender stage trypanosomes express the mRNA and protein of a known stumpy stage marker, complete the complex life cycle in the fly as successfully as the stumpy stage, and require only a single parasite for productive infection. These findings suggest a reassessment of the traditional view of the trypanosome life cycle. They may also provide a solution to a long-lasting paradox, namely the successful transmission of parasites in chronic infections, despite low parasitemia.}, language = {en} } @phdthesis{Zachary2021, author = {Zachary, Marie}, title = {Functional characterization of small non-coding RNAs of \(Neisseria\) \(gonorrhoeae\)}, doi = {10.25972/OPUS-24582}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245826}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {During infection, bacteria need to adapt to a changing environment and have to endure various stress conditions. Small non-coding RNAs are considered as important regulators of bacterial gene expression and so allow quick adaptations by altering expression of specific target genes. Regulation of gene expression in the human-restricted pathogen Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhoea, is only poorly understood. The present study aims a better understanding of gene regulation in N. gonorrhoeae by studying small non-coding RNAs. The discovery of antisense RNAs for all opa genes led to the hypothesis of asRNA-mediated degradation of out-of-frame opa transcripts. Analysis of asRNA expression revealed a very low abundance of the transcripts and inclusion of another phase-variable gene in the study indicates that the asRNAs are not involved in degradation of out-of-frame transcripts. This doctoral thesis focuses on the analysis of trans-acting sRNAs. The sibling sRNAs NgncR_162 and NgncR_163 were discovered as post-transcriptional regulators altering expression of genes involved in metabolic processes, amino acid uptake and transcriptional regulation. A more detailed analysis by in silico and transcriptomic approaches showed that the sRNAs regulate a broad variety of genes coding for proteins of central metabolism, amino acid biosynthesis and degradation and several transport processes. Expression levels of the sibling sRNAs depend on the growth phase of the bacteria and on the growth medium. This indicates that NgncR_162 and NgncR_163 are involved in the adaptation of the gonococcal metabolism to specific growth conditions. This work further initiates characterisation of the sRNA NgncR_237. An in silico analysis showed details on sequence conservation and a possible secondary structure. A combination of in silico target prediction and differential RNA sequencing resulted in the identification of several target genes involved in type IV pilus biogenesis and DNA recombination. However, it was not successful to find induction conditions for sRNA expression. Interestingly, a possible sibling sRNA could be identified that shares the target interaction sequence with NgncR_237 and could therefore target the same mRNAs. In conclusion, this thesis provides further insights in gene regulation by non-coding RNAs in N. gonorrhoeae by analysing two pairs of sibling sRNAs modulating bacterial metabolism or possibly type IV pilus biogenesis.}, subject = {Neisseria gonorrhoeae}, language = {en} }