@article{BemmBeckerLarischetal.2016, author = {Bemm, Felix and Becker, Dirk and Larisch, Christina and Kreuzer, Ines and Escalante-Perez, Maria and Schulze, Waltraud X. and Ankenbrand, Markus and Van de Weyer, Anna-Lena and Krol, Elzbieta and Al-Rasheid, Khaled A. and Mith{\"o}fer, Axel and Weber, Andreas P. and Schultz, J{\"o}rg and Hedrich, Rainer}, title = {Venus flytrap carnivorous lifestyle builds on herbivore defense strategies}, series = {Genome Research}, volume = {26}, journal = {Genome Research}, number = {6}, doi = {10.1101/gr.202200.115}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188799}, pages = {812-825}, year = {2016}, abstract = {Although the concept of botanical carnivory has been known since Darwin's time, the molecular mechanisms that allow animal feeding remain unknown, primarily due to a complete lack of genomic information. Here, we show that the transcriptomic landscape of the Dionaea trap is dramatically shifted toward signal transduction and nutrient transport upon insect feeding, with touch hormone signaling and protein secretion prevailing. At the same time, a massive induction of general defense responses is accompanied by the repression of cell death-related genes/processes. We hypothesize that the carnivory syndrome of Dionaea evolved by exaptation of ancient defense pathways, replacing cell death with nutrient acquisition.}, language = {en} } @article{BenoitAdelmanReinhardtetal.2016, author = {Benoit, Joshua B. and Adelman, Zach N. and Reinhardt, Klaus and Dolan, Amanda and Poelchau, Monica and Jennings, Emily C. and Szuter, Elise M. and Hagan, Richard W. and Gujar, Hemant and Shukla, Jayendra Nath and Zhu, Fang and Mohan, M. and Nelson, David R. and Rosendale, Andrew J. and Derst, Christian and Resnik, Valentina and Wernig, Sebastian and Menegazzi, Pamela and Wegener, Christian and Peschel, Nicolai and Hendershot, Jacob M. and Blenau, Wolfgang and Predel, Reinhard and Johnston, Paul R. and Ioannidis, Panagiotis and Waterhouse, Robert M. and Nauen, Ralf and Schorn, Corinna and Ott, Mark-Christoph and Maiwald, Frank and Johnston, J. Spencer and Gondhalekar, Ameya D. and Scharf, Michael E. and Raje, Kapil R. and Hottel, Benjamin A. and Armis{\´e}n, David and Crumi{\`e}re, Antonin Jean Johan and Refki, Peter Nagui and Santos, Maria Emilia and Sghaier, Essia and Viala, S{\`e}verine and Khila, Abderrahman and Ahn, Seung-Joon and Childers, Christopher and Lee, Chien-Yueh and Lin, Han and Hughes, Daniel S.T. and Duncan, Elizabeth J. and Murali, Shwetha C. and Qu, Jiaxin and Dugan, Shannon and Lee, Sandra L. and Chao, Hsu and Dinh, Huyen and Han, Yi and Doddapaneni, Harshavardhan and Worley, Kim C. and Muzny, Donna M. and Wheeler, David and Panfilio, Kristen A. and Jentzsch, Iris M. Vargas and Jentzsch, IMV and Vargo, Edward L. and Booth, Warren and Friedrich, Markus and Weirauch, Matthew T. and Anderson, Michelle A.E. and Jones, Jeffery W. and Mittapalli, Omprakash and Zhao, Chaoyang and Zhou, Jing-Jiang and Evans, Jay D. and Attardo, Geoffrey M. and Robertson, Hugh M. and Zdobnov, Evgeny M. and Ribeiro, Jose M.C. and Gibbs, Richard A. and Werren, John H. and Palli, Subba R. and Schal, Coby and Richards, Stephen}, title = {Unique features of a global human ectoparasite identified through sequencing of the bed bug genome}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, number = {10165}, doi = {10.1038/ncomms10165}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166221}, year = {2016}, abstract = {The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite throughout much of the world during the past two decades. This global resurgence is likely linked to increased international travel and commerce in addition to widespread insecticide resistance. Analyses of the C. lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding genes provide a comprehensive representation of genes that are linked to traumatic insemination, a reduced chemosensory repertoire of genes related to obligate hematophagy, host-symbiont interactions, and several mechanisms of insecticide resistance. In addition, we document the presence of multiple putative lateral gene transfer events. Genome sequencing and annotation establish a solid foundation for future research on mechanisms of insecticide resistance, human-bed bug and symbiont-bed bug associations, and unique features of bed bug biology that contribute to the unprecedented success of C. lectularius as a human ectoparasite.}, language = {en} } @article{HackerEscalonaEspinosaConsalvoetal.2016, author = {Hacker, Ulrich T. and Escalona-Espinosa, Laura and Consalvo, Nicola and Goede, Valentin and Schiffmann, Lars and Scherer, Stefan J. and Hedge, Priti and Van Cutsem, Eric and Coutelle, Oliver and B{\"u}ning, Hildegard}, title = {Evaluation of Angiopoietin-2 as a biomarker in gastric cancer: results from the randomised phase III AVAGAST trial}, series = {British Journal of Cancer}, volume = {114}, journal = {British Journal of Cancer}, number = {8}, doi = {10.1038/bjc.2016.30}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189578}, pages = {855-862}, year = {2016}, abstract = {Background: In the phase III AVAGAST trial, the addition of bevacizumab to chemotherapy improved progression-free survival (PFS) but not overall survival (OS) in patients with advanced gastric cancer. We studied the role of Angiopoietin-2 (Ang-2), a key driver of tumour angiogenesis, metastasis and resistance to antiangiogenic treatment, as a biomarker. Methods: Previously untreated, advanced gastric cancer patients were randomly assigned to receive bevacizumab (n = 387) or placebo (n = 387) in combination with chemotherapy. Plasma collected at baseline and at progression was analysed by ELISA. The role of Ang-2 as a prognostic and a predictive biomarker of bevacizumab efficacy was studied using a Cox proportional hazards model. Logistic regression analysis was applied for correlations with metastasis. Results: Median baseline plasma Ang-2 levels were lower in Asian (2143 pg ml\(^-\)\(^1\)) vs non-Asian patients (3193 pg ml\(^-\)\(^1\)), P<0.0001. Baseline plasma Ang-2 was identified as an independent prognostic marker for OS but did not predict bevacizumab efficacy alone or in combination with baseline VEGF. Baseline plasma Ang-2 correlated with the frequency of liver metastasis (LM) at any time: Odds ratio per 1000 pg ml\(^-\)\(^1\) increase: 1.19; 95\% CI 1.10-1.29; P<0.0001 (non-Asians) and 1.37; 95\% CI 1.13-1.64; P = 0.0010 (Asians). Conclusions: Baseline plasma Ang-2 is a novel prognostic biomarker for OS in advanced gastric cancer strongly associated with LM. Differences in Ang-2 mediated vascular response may, in part, account for outcome differences between Asian and non-Asian patients; however, data have to be further validated. Ang-2 is a promising drug target in gastric cancer.}, language = {en} } @article{GomezHFelipeMedinaSanchezMartinetal.2016, author = {Gom{\´e}z-H, Laura and Felipe-Medina, Natalia and S{\´a}nchez-Mart{\´i}n, Manuel and Davies, Owen R. and Ramos, Isabel and Garc{\´i}a-Tu{\~n}{\´o}n, Ignacio and de Rooij, Dirk G. and Dereli, Ihsan and T{\´o}th, Attila and Barbero, Jos{\´e} Luis and Benavente, Ricardo and Llano, Elena and Pendas, Alberto M.}, title = {C14ORF39/SIX6OS1 is a constituent of the synaptonemal complex and is essential for mouse fertility}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms13298}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165907}, pages = {13298}, year = {2016}, abstract = {Meiotic recombination generates crossovers between homologous chromosomes that are essential for genome haploidization. The synaptonemal complex is a 'zipper'-like protein assembly that synapses homologue pairs together and provides the structural framework for processing recombination sites into crossovers. Humans show individual differences in the number of crossovers generated across the genome. Recently, an anonymous gene variant in C14ORF39/SIX6OS1 was identified that influences the recombination rate in humans. Here we show that C14ORF39/SIX6OS1 encodes a component of the central element of the synaptonemal complex. Yeast two-hybrid analysis reveals that SIX6OS1 interacts with the well-established protein synaptonemal complex central element 1 (SYCE1). Mice lacking SIX6OS1 are defective in chromosome synapsis at meiotic prophase I, which provokes an arrest at the pachytene-like stage and results in infertility. In accordance with its role as a modifier of the human recombination rate, SIX6OS1 is essential for the appropriate processing of intermediate recombination nodules before crossover formation.}, language = {en} } @article{DiaoMoussetHorsburghetal.2016, author = {Diao, Wenwen and Mousset, Mathilde and Horsburgh, Gavin J. and Vermeulen, Cornelis J. and Johannes, Frank and van de Zande, Louis and Ritchie, Michael G. and Schmitt, Thomas and Beukeboom, Leo W.}, title = {Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps}, series = {G3: Genes Genomes Genetics}, volume = {6}, journal = {G3: Genes Genomes Genetics}, number = {6}, doi = {10.1534/g3.116.029074}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165412}, pages = {1549-1562}, year = {2016}, abstract = {A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences.}, language = {en} } @article{daCruzRodriguezCasuriagaSantinaqueetal.2016, author = {da Cruz, Irene and Rodr{\´i}guez-Casuriaga, Rosana and Santi{\~n}aque, Frederico F. and Far{\´i}as, Joaquina and Curti, Gianni and Capoano, Carlos A. and Folle, Gustavo A. and Benavente, Ricardo and Sotelo-Silveira, Jos{\´e} Roberto and Geisinger, Adriana}, title = {Transcriptome analysis of highly purified mouse spermatogenic cell populations: gene expression signatures switch from meiotic-to postmeiotic-related processes at pachytene stage}, series = {BMC Genomics}, volume = {17}, journal = {BMC Genomics}, doi = {10.1186/s12864-016-2618-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164574}, pages = {294}, year = {2016}, abstract = {Background Spermatogenesis is a complex differentiation process that involves the successive and simultaneous execution of three different gene expression programs: mitotic proliferation of spermatogonia, meiosis, and spermiogenesis. Testicular cell heterogeneity has hindered its molecular analyses. Moreover, the characterization of short, poorly represented cell stages such as initial meiotic prophase ones (leptotene and zygotene) has remained elusive, despite their crucial importance for understanding the fundamentals of meiosis. Results We have developed a flow cytometry-based approach for obtaining highly pure stage-specific spermatogenic cell populations, including early meiotic prophase. Here we combined this methodology with next generation sequencing, which enabled the analysis of meiotic and postmeiotic gene expression signatures in mouse with unprecedented reliability. Interestingly, we found that a considerable number of genes involved in early as well as late meiotic processes are already on at early meiotic prophase, with a high proportion of them being expressed only for the short time lapse of lepto-zygotene stages. Besides, we observed a massive change in gene expression patterns during medium meiotic prophase (pachytene) when mostly genes related to spermiogenesis and sperm function are already turned on. This indicates that the transcriptional switch from meiosis to post-meiosis takes place very early, during meiotic prophase, thus disclosing a higher incidence of post-transcriptional regulation in spermatogenesis than previously reported. Moreover, we found that a good proportion of the differential gene expression in spermiogenesis corresponds to up-regulation of genes whose expression starts earlier, at pachytene stage; this includes transition protein-and protamine-coding genes, which have long been claimed to switch on during spermiogenesis. In addition, our results afford new insights concerning X chromosome meiotic inactivation and reactivation. Conclusions This work provides for the first time an overview of the time course for the massive onset and turning off of the meiotic and spermiogenic genetic programs. Importantly, our data represent a highly reliable information set about gene expression in pure testicular cell populations including early meiotic prophase, for further data mining towards the elucidation of the molecular bases of male reproduction in mammals.}, language = {en} } @article{ShenChalopinGarciaetal.2016, author = {Shen, Yingjia and Chalopin, Domitille and Garcia, Tzintzuni and Boswell, Mikki and Boswell, William and Shiryev, Sergey A. and Agarwala, Richa and Volff, Jean-Nicolas and Postlethwait, John H. and Schartl, Manfred and Minx, Patrick and Warren, Wesley C. and Walter, Ronald B.}, title = {X. couchianus and X. hellerii genome models provide genomic variation insight among Xiphophorus species}, series = {BMC Genomics}, volume = {17}, journal = {BMC Genomics}, doi = {10.1186/s12864-015-2361-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164582}, pages = {37}, year = {2016}, abstract = {Background Xiphophorus fishes are represented by 26 live-bearing species of tropical fish that express many attributes (e.g., viviparity, genetic and phenotypic variation, ecological adaptation, varied sexual developmental mechanisms, ability to produce fertile interspecies hybrids) that have made attractive research models for over 85 years. Use of various interspecies hybrids to investigate the genetics underlying spontaneous and induced tumorigenesis has resulted in the development and maintenance of pedigreed Xiphophorus lines specifically bred for research. The recent availability of the X. maculatus reference genome assembly now provides unprecedented opportunities for novel and exciting comparative research studies among Xiphophorus species. Results We present sequencing, assembly and annotation of two new genomes representing Xiphophorus couchianus and Xiphophorus hellerii. The final X. couchianus and X. hellerii assemblies have total sizes of 708 Mb and 734 Mb and correspond to 98 \% and 102 \% of the X. maculatus Jp 163 A genome size, respectively. The rates of single nucleotide change range from 1 per 52 bp to 1 per 69 bp among the three genomes and the impact of putatively damaging variants are presented. In addition, a survey of transposable elements allowed us to deduce an ancestral TE landscape, uncovered potential active TEs and document a recent burst of TEs during evolution of this genus. Conclusions Two new Xiphophorus genomes and their corresponding transcriptomes were efficiently assembled, the former using a novel guided assembly approach. Three assembled genome sequences within this single vertebrate order of new world live-bearing fishes will accelerate our understanding of relationship between environmental adaptation and genome evolution. In addition, these genome resources provide capability to determine allele specific gene regulation among interspecies hybrids produced by crossing any of the three species that are known to produce progeny predisposed to tumor development.}, language = {en} } @article{HartelGloggerJonesetal.2016, author = {Hartel, Andreas J.W. and Glogger, Marius and Jones, Nicola G. and Abuillan, Wasim and Batram, Christopher and Hermann, Anne and Fenz, Susanne F. and Tanaka, Motomu and Engstler, Markus}, title = {N-glycosylation enables high lateral mobility of GPI-anchored proteins at a molecular crowding threshold}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms12870}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171368}, year = {2016}, abstract = {The protein density in biological membranes can be extraordinarily high, but the impact of molecular crowding on the diffusion of membrane proteins has not been studied systematically in a natural system. The diversity of the membrane proteome of most cells may preclude systematic studies. African trypanosomes, however, feature a uniform surface coat that is dominated by a single type of variant surface glycoprotein (VSG). Here we study the density-dependence of the diffusion of different glycosylphosphatidylinositol-anchored VSG-types on living cells and in artificial membranes. Our results suggest that a specific molecular crowding threshold (MCT) limits diffusion and hence affects protein function. Obstacles in the form of heterologous proteins compromise the diffusion coefficient and the MCT. The trypanosome VSG-coat operates very close to its MCT. Importantly, our experiments show that N-linked glycans act as molecular insulators that reduce retarding intermolecular interactions allowing membrane proteins to function correctly even when densely packed.}, language = {en} } @article{PetersHempAppelhansetal.2016, author = {Peters, Marcell K. and Hemp, Andreas and Appelhans, Tim and Behler, Christina and Classen, Alice and Detsch, Florian and Ensslin, Andreas and Ferger, Stefan W. and Frederiksen, Sara B. and Gebert, Frederike and Haas, Michael and Helbig-Bonitz, Maria and Hemp, Claudia and Kindeketa, William J. and Mwangomo, Ephraim and Ngereza, Christine and Otte, Insa and R{\"o}der, Juliane and Rutten, Gemma and Costa, David Schellenberger and Tardanico, Joseph and Zancolli, Giulia and Deckert, J{\"u}rgen and Eardley, Connal D. and Peters, Ralph S. and R{\"o}del, Mark-Oliver and Schleuning, Matthias and Ssymank, Axel and Kakengi, Victor and Zhang, Jie and B{\"o}hning-Gaese, Katrin and Brandl, Roland and Kalko, Elisabeth K.V. and Kleyer, Michael and Nauss, Thomas and Tschapka, Marco and Fischer, Markus and Steffan-Dewenter, Ingolf}, title = {Predictors of elevational biodiversity gradients change from single taxa to the multi-taxa community level}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms13736}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169374}, year = {2016}, abstract = {The factors determining gradients of biodiversity are a fundamental yet unresolved topic in ecology. While diversity gradients have been analysed for numerous single taxa, progress towards general explanatory models has been hampered by limitations in the phylogenetic coverage of past studies. By parallel sampling of 25 major plant and animal taxa along a 3.7 km elevational gradient on Mt. Kilimanjaro, we quantify cross-taxon consensus in diversity gradients and evaluate predictors of diversity from single taxa to a multi-taxa community level. While single taxa show complex distribution patterns and respond to different environmental factors, scaling up diversity to the community level leads to an unambiguous support for temperature as the main predictor of species richness in both plants and animals. Our findings illuminate the influence of taxonomic coverage for models of diversity gradients and point to the importance of temperature for diversification and species coexistence in plant and animal communities.}, language = {en} } @article{GattoSchulzeNielsen2016, author = {Gatto, Francesco and Schulze, Almut and Nielsen, Jens}, title = {Systematic Analysis Reveals that Cancer Mutations Converge on Deregulated Metabolism of Arachidonate and Xenobiotics}, series = {Cell Reports}, volume = {16}, journal = {Cell Reports}, number = {3}, doi = {10.1016/j.celrep.2016.06.038}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164814}, pages = {878-895}, year = {2016}, abstract = {Mutations are the basis of the clonal evolution of most cancers. Nevertheless, a systematic analysis of whether mutations are selected in cancer because they lead to the deregulation of specific biological processes independent of the type of cancer is still lacking. In this study, we correlated the genome and transcriptome of 1,082 tumors. We found that nine commonly mutated genes correlated with substantial changes in gene expression, which primarily converged on metabolism. Further network analyses circumscribed the convergence to a network of reactions, termed AraX, that involves the glutathione- and oxygen-mediated metabolism of arachidonic acid and xenobiotics. In an independent cohort of 4,462 samples, all nine mutated genes were consistently correlated with the deregulation of AraX. Among all of the metabolic pathways, AraX deregulation represented the strongest predictor of patient survival. These findings suggest that oncogenic mutations drive a selection process that converges on the deregulation of the AraX network.}, language = {en} } @article{SenthilanHelfrichFoerster2016, author = {Senthilan, Pingkalai R. and Helfrich-F{\"o}rster, Charlotte}, title = {Rhodopsin 7-The unusual Rhodopsin in Drosophila}, series = {PeerJ}, volume = {4}, journal = {PeerJ}, doi = {10.7717/peerj.2427}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177998}, year = {2016}, abstract = {Rhodopsins are the major photopigments in the fruit fly Drosophila melanogaster. Drosophila express six well-characterized Rhodopsins (Rh1-Rh6) with distinct absorption maxima and expression pattern. In 2000, when the Drosophila genome was published, a novel Rhodopsin gene was discovered: Rhodopsin 7 (Rh7). Rh7 is highly conserved among the Drosophila genus and is also found in other arthropods. Phylogenetic trees based on protein sequences suggest that the seven Drosophila Rhodopsins cluster in three different groups. While Rh1, Rh2 and Rh6 form a "vertebrate-melanopsin-type"-cluster, and Rh3, Rh4 and Rh5 form an "insect-type"-Rhodopsin cluster, Rh7 seem to form its own cluster. Although Rh7 has nearly all important features of a functional Rhodopsin, it differs from other Rhodopsins in its genomic and structural properties, suggesting it might have an overall different role than other known Rhodopsins.}, language = {en} } @article{FeldbauerSchlegelWeissbeckeretal.2016, author = {Feldbauer, Katrin and Schlegel, Jan and Weissbecker, Juliane and Sauer, Frank and Wood, Phillip G. and Bamberg, Ernst and Terpitz, Ulrich}, title = {Optochemokine Tandem for Light-Control of Intracellular Ca\(^{2+}\)}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0165344}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178921}, year = {2016}, abstract = {An optochemokine tandem was developed to control the release of calcium from endosomes into the cytosol by light and to analyze the internalization kinetics of G-protein coupled receptors (GPCRs) by electrophysiology. A previously constructed rhodopsin tandem was re-engineered to combine the light-gated Ca\(^{2+}\)-permeable cation channel Channelrhodopsin-2(L132C), CatCh, with the chemokine receptor CXCR4 in a functional tandem protein tCXCR4/CatCh. The GPCR was used as a shuttle protein to displace CatCh from the plasma membrane into intracellular areas. As shown by patch-clamp measurements and confocal laser scanning microscopy, heterologously expressed tCXCR4/CatCh was internalized via the endocytic SDF1/CXCR4 signaling pathway. The kinetics of internalization could be followed electrophysiologically via the amplitude of the CatCh signal. The light-induced release of Ca\(^{2+}\) by tandem endosomes into the cytosol via CatCh was visualized using the Ca\(^{2+}\)-sensitive dyes rhod2 and rhod2-AM showing an increase of intracellular Ca\(^{2+}\) in response to light.}, language = {en} } @article{FischerHelfrichFoersterPeschel2016, author = {Fischer, Robin and Helfrich-F{\"o}rster, Charlotte and Peschel, Nicolai}, title = {GSK-3 Beta Does Not Stabilize Cryptochrome in the Circadian Clock of Drosophila}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0146571}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-180370}, year = {2016}, abstract = {Cryptochrome (CRY) is the primary photoreceptor of Drosophila's circadian clock. It resets the circadian clock by promoting light-induced degradation of the clock protein Timeless (TIM) in the proteasome. Under constant light, the clock stops because TIM is absent, and the flies become arrhythmic. In addition to TIM degradation, light also induces CRY degradation. This depends on the interaction of CRY with several proteins such as the E3 ubiquitin ligases Jetlag (JET) and Ramshackle (BRWD3). However, CRY can seemingly also be stabilized by interaction with the kinase Shaggy (SGG), the GSK-3 beta fly orthologue. Consequently, flies with SGG overexpression in certain dorsal clock neurons are reported to remain rhythmic under constant light. We were interested in the interaction between CRY, Ramshackle and SGG and started to perform protein interaction studies in S2 cells. To our surprise, we were not able to replicate the results, that SGG overexpression does stabilize CRY, neither in S2 cells nor in the relevant clock neurons. SGG rather does the contrary. Furthermore, flies with SGG overexpression in the dorsal clock neurons became arrhythmic as did wild-type flies. Nevertheless, we could reproduce the published interaction of SGG with TIM, since flies with SGG overexpression in the lateral clock neurons shortened their free-running period. We conclude that SGG does not directly interact with CRY but rather with TIM. Furthermore we could demonstrate, that an unspecific antibody explains the observed stabilization effects on CRY.}, language = {en} } @article{DePalmaAbrahamczykAizenetal.2016, author = {De Palma, Adriana and Abrahamczyk, Stefan and Aizen, Marcelo A. and Albrecht, Matthias and Basset, Yves and Bates, Adam and Blake, Robin J. and Boutin, C{\´e}line and Bugter, Rob and Connop, Stuart and Cruz-L{\´o}pez, Leopoldo and Cunningham, Saul A. and Darvill, Ben and Diek{\"o}tter, Tim and Dorn, Silvia and Downing, Nicola and Entling, Martin H. and Farwig, Nina and Felicioli, Antonio and Fonte, Steven J. and Fowler, Robert and Franzen, Markus Franz{\´e}n and Goulson, Dave and Grass, Ingo and Hanley, Mick E. and Hendrix, Stephen D. and Herrmann, Farina and Herzog, Felix and Holzschuh, Andrea and Jauker, Birgit and Kessler, Michael and Knight, M. E. and Kruess, Andreas and Lavelle, Patrick and Le F{\´e}on, Violette and Lentini, Pia and Malone, Louise A. and Marshall, Jon and Mart{\´i}nez Pach{\´o}n, Eliana and McFrederick, Quinn S. and Morales, Carolina L. and Mudri-Stojnic, Sonja and Nates-Parra, Guiomar and Nilsson, Sven G. and {\"O}ckinger, Erik and Osgathorpe, Lynne and Parra-H, Alejandro and Peres, Carlos A. and Persson, Anna S. and Petanidou, Theodora and Poveda, Katja and Power, Eileen F. and Quaranta, Marino and Quintero, Carolina and Rader, Romina and Richards, Miriam H. and Roulston, T'ai and Rousseau, Laurent and Sadler, Jonathan P. and Samneg{\aa}rd, Ulrika and Schellhorn, Nancy A. and Sch{\"u}epp, Christof and Schweiger, Oliver and Smith-Pardo, Allan H. and Steffan-Dewenter, Ingolf and Stout, Jane C. and Tonietto, Rebecca K. and Tscharntke, Teja and Tylianakis, Jason M. and Verboven, Hans A. F. and Vergara, Carlos H. and Verhulst, Jort and Westphal, Catrin and Yoon, Hyung Joo and Purvis, Andy}, title = {Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, doi = {10.1038/srep31153}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167642}, pages = {31153}, year = {2016}, abstract = {Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.}, language = {en} } @article{HolzschuhDaineseGonzalezVaroetal.2016, author = {Holzschuh, Andrea and Dainese, Matteo and Gonzalez-Varo, Juan P. and Mudri-Stojnic, Sonja and Riedinger, Verena and Rundl{\"o}f, Maj and Scheper, Jeroen and Wickens, Jennifer B. and Wickens, Victoria J. and Bommarco, Riccardo and Kleijn, David and Potts, Simon G. and Roberts, Stuart P. M. and Smith, Henrik G. and Vil{\`a}, Montserrat and Vujic, Ante and Steffan-Dewenter, Ingolf}, title = {Mass-flowering crops dilute pollinator abundance in agricultural landscapes across Europe}, series = {Ecology Letters}, volume = {19}, journal = {Ecology Letters}, number = {10}, doi = {10.1111/ele.12657}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187356}, pages = {1228-1236}, year = {2016}, abstract = {Mass-flowering crops (MFCs) are increasingly cultivated and might influence pollinator communities in MFC fields and nearby semi-natural habitats (SNHs). Across six European regions and 2 years, we assessed how landscape-scale cover of MFCs affected pollinator densities in 408 MFC fields and adjacent SNHs. In MFC fields, densities of bumblebees, solitary bees, managed honeybees and hoverflies were negatively related to the cover of MFCs in the landscape. In SNHs, densities of bumblebees declined with increasing cover of MFCs but densities of honeybees increased. The densities of all pollinators were generally unrelated to the cover of SNHs in the landscape. Although MFC fields apparently attracted pollinators from SNHs, in landscapes with large areas of MFCs they became diluted. The resulting lower densities might negatively affect yields of pollinator- dependent crops and the reproductive success of wild plants. An expansion of MFCs needs to be accompanied by pollinator-supporting practices in agricultural landscapes.}, language = {en} } @article{WoelflingBeckerUhletal.2016, author = {W{\"o}lfling, Mirko and Becker, Mira C. and Uhl, Britta and Traub, Anja and Fiedler, Konrad}, title = {How differences in the settling behaviour of moths (Lepidoptera) may contribute to sampling bias when using automated light traps}, series = {European Journal of Entomology}, volume = {113}, journal = {European Journal of Entomology}, doi = {10.14411/eje.2016.066}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191154}, pages = {502-506}, year = {2016}, abstract = {Quantitative community-wide moth surveys frequently employ flight-interception traps equipped with UV-light emitting sources as attractants. It has long been known that moth species differ in their responsiveness to light traps. We studied how the settling behaviour of moths at a light trap may further contribute to sampling bias. We observed the behaviour of 1426 moths at a light tower. Moths were classified as either, settling and remaining still after arrival, or continually moving on the gauze for extended periods of time. Moths that did not move after settling may not end up in the sampling container of the light trap and therefore are under-represented in automated trap samples relative to their true proportions in the community. Our analyses revealed highly significant behavioural differences between moths that differed in body size. Small moths were more likely to remain stationary after settling. As a corollary, representatives of three taxa, which in Europe are predominantly small species (Nolidae, Geometridae: Eupitheciini, Erebidae: Lithosiini), usually settled down immediately, whereas most other moths remained active on or flying around the trap for some time. Moth behaviour was also modulated by ambient temperature. At high temperatures, they were less likely to settle down immediately, but this behavioural difference was most strongly apparent among medium-sized moths. These results indicate the likely extent of the sampling bias when analysing and interpreting automated light-trap samples. Furthermore, to control for temperature modulated sampling bias temperature should always be recorded when sampling moths using flight-interception traps.}, language = {en} } @article{KramerPiperEstevezetal.2016, author = {Kramer, Susanne and Piper, Sophie and Estevez, Antonio and Carrington, Mark}, title = {Polycistronic trypanosome mRNAs are a target for the exosome}, series = {Molecular and Biochemical Parasitology}, volume = {205}, journal = {Molecular and Biochemical Parasitology}, number = {1-2}, doi = {10.1016/j.molbiopara.2016.02.009}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191350}, pages = {1-5}, year = {2016}, abstract = {Eukaryotic cells have several mRNA quality control checkpoints to avoid the production of aberrant proteins. Intron-containing mRNAs are actively degraded by the nuclear exosome, prevented from nuclear exit and, if these systems fail, degraded by the cytoplasmic NMD machinery. Trypanosomes have only two introns. However, they process mRNA5 from long polycistronic precursors by trans-splicing and polycistronic mRNA molecules frequently arise from any missed splice site. Here, we show that RNAi depletion of the trypanosome exosome, but not of the cytoplasmic 5'-3' exoribonuclease XRNA or the NMD helicase UPF1, causes accumulation of oligocistronic mRNA5. We have also revisited the localization of the trypanosome exosome by expressing eYFP-fusion proteins of the exosome subunits RRP44 and RRP6. Both proteins are significantly enriched in the nucleus. Together with published data, our data suggest a major nuclear function of the trypanosome exosome in rRNA, snoRNA and mRNA quality control.}, language = {en} } @article{MederKoenigOzretićetal.2016, author = {Meder, Lydia and K{\"o}nig, Katharina and Ozretić, Luka and Schultheis, Anne M. and Ueckeroth, Frank and Ade, Carsten P. and Albus, Kerstin and Boehm, Diana and Rommerscheidt-Fuss, Ursula and Florin, Alexandra and Buhl, Theresa and Hartmann, Wolfgang and Wolf, J{\"u}rgen and Merkelbach-Bruse, Sabine and Eilers, Martin and Perner, Sven and Heukamp, Lukas C. and Buettner, Reinhard}, title = {NOTCH, ASCL1, p53 and RB alterations define an alternative pathway driving neuroendocrine and small cell lung carcinomas}, series = {International Journal of Cancer}, volume = {138}, journal = {International Journal of Cancer}, number = {4}, doi = {10.1002/ijc.29835}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190853}, pages = {927-938}, year = {2016}, abstract = {Small cell lung cancers (SCLCs) and extrapulmonary small cell cancers (SCCs) are very aggressive tumors arising de novo as primary small cell cancer with characteristic genetic lesions in RB1 and TP53. Based on murine models, neuroendocrine stem cells of the terminal bronchioli have been postulated as the cellular origin of primary SCLC. However, both in lung and many other organs, combined small cell/non-small cell tumors and secondary transitions from non-small cell carcinomas upon cancer therapy to neuroendocrine and small cell tumors occur. We define features of "small cell-ness" based on neuroendocrine markers, characteristic RB1 and TP53 mutations and small cell morphology. Furthermore, here we identify a pathway driving the pathogenesis of secondary SCLC involving inactivating NOTCH mutations, activation of the NOTCH target ASCL1 and canonical WNT-signaling in the context of mutual bi-allelic RB1 and TP53 lesions. Additionaly, we explored ASCL1 dependent RB inactivation by phosphorylation, which is reversible by CDK5 inhibition. We experimentally verify the NOTCH-ASCL1-RB-p53 signaling axis in vitro and validate its activation by genetic alterations in vivo. We analyzed clinical tumor samples including SCLC, SCC and pulmonary large cell neuroendocrine carcinomas and adenocarcinomas using amplicon-based Next Generation Sequencing, immunohistochemistry and fluorescence in situ hybridization. In conclusion, we identified a novel pathway underlying rare secondary SCLC which may drive small cell carcinomas in organs other than lung, as well.}, language = {en} } @article{SinghVermaAkhoonetal.2016, author = {Singh, Krishna P. and Verma, Neeraj and Akhoon, Bashir A . and Bhatt, Vishal and Gupta, Shishir K. and Gupta, Shailendra K. and Smita, Suchi}, title = {Sequence-based approach for rapid identification of cross-clade CD8+ T-cell vaccine candidates from all high-risk HPV strains}, series = {3 Biotech}, volume = {6}, journal = {3 Biotech}, doi = {10.1007/s13205-015-0352-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191056}, pages = {10}, year = {2016}, abstract = {Human papilloma virus (HPV) is the primary etiological agent responsible for cervical cancer in women. Although in total 16 high-risk HPV strains have been identified so far. Currently available commercial vaccines are designed by targeting mainly HPV16 and HPV18 viral strains as these are the most common strains associated with cervical cancer. Because of the high level of antigenic specificity of HPV capsid antigens, the currently available vaccines are not suitable to provide cross-protection from all other high-risk HPV strains. Due to increasing reports of cervical cancer cases from other HPV high-risk strains other than HPV16 and 18, it is crucial to design vaccine that generate reasonable CD8+ T-cell responses for possibly all the high-risk strains. With this aim, we have developed a computational workflow to identify conserved cross-clade CD8+ T-cell HPV vaccine candidates by considering E1, E2, E6 and E7 proteins from all the high-risk HPV strains. We have identified a set of 14 immunogenic conserved peptide fragments that are supposed to provide protection against infection from any of the high-risk HPV strains across globe.}, language = {en} } @article{VieraElMerahbiNieswandtetal.2016, author = {Viera, Jonathan Trujillo and El-Merahbi, Rabih and Nieswandt, Bernhard and Stegner, David and Sumara, Grzegorz}, title = {Phospholipases D1 and D2 Suppress Appetite and Protect against Overweight}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0157607}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179729}, year = {2016}, abstract = {Obesity is a major risk factor predisposing to the development of peripheral insulin resistance and type 2 diabetes (T2D). Elevated food intake and/or decreased energy expenditure promotes body weight gain and acquisition of adipose tissue. Number of studies implicated phospholipase D (PLD) enzymes and their product, phosphatidic acid (PA), in regulation of signaling cascades controlling energy intake, energy dissipation and metabolic homeostasis. However, the impact of PLD enzymes on regulation of metabolism has not been directly determined so far. In this study we utilized mice deficient for two major PLD isoforms, PLD1 and PLD2, to assess the impact of these enzymes on regulation of metabolic homeostasis. We showed that mice lacking PLD1 or PLD2 consume more food than corresponding control animals. Moreover, mice deficient for PLD2, but not PLD1, present reduced energy expenditure. In addition, deletion of either of the PLD enzymes resulted in development of elevated body weight and increased adipose tissue content in aged animals. Consistent with the fact that elevated content of adipose tissue predisposes to the development of hyperlipidemia and insulin resistance, characteristic for the pre-diabetic state, we observed that Pld1\(^{-/-}\) and Pld2\(^{-/-}\) mice present elevated free fatty acids (FFA) levels and are insulin as well as glucose intolerant. In conclusion, our data suggest that deficiency of PLD1 or PLD2 activity promotes development of overweight and diabetes.}, language = {en} } @article{LetunicBork2016, author = {Letunic, Ivica and Bork, Peer}, title = {Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees}, series = {Nucleic Acids Research}, volume = {44}, journal = {Nucleic Acids Research}, number = {W1}, doi = {10.1093/nar/gkw290}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166181}, pages = {W242-W245}, year = {2016}, abstract = {Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. The current version was completely redesigned and rewritten, utilizing current web technologies for speedy and streamlined processing. Numerous new features were introduced and several new data types are now supported. Trees with up to 100,000 leaves can now be efficiently displayed. Full interactive control over precise positioning of various annotation features and an unlimited number of datasets allow the easy creation of complex tree visualizations. iTOL 3 is the first tool which supports direct visualization of the recently proposed phylogenetic placements format. Finally, iTOL's account system has been redesigned to simplify the management of trees in user-defined workspaces and projects, as it is heavily used and currently handles already more than 500,000 trees from more than 10,000 individual users.}, language = {en} } @article{KupperStigloherFeldhaaretal.2016, author = {Kupper, Maria and Stigloher, Christian and Feldhaar, Heike and Gross, Roy}, title = {Distribution of the obligate endosymbiont Blochmannia floridanus and expression analysis of putative immune genes in ovaries of the carpenter ant Camponotus floridanus}, series = {Arthropod Structure \& Development}, volume = {45}, journal = {Arthropod Structure \& Development}, number = {5}, doi = {10.1016/j.asd.2016.09.004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187482}, pages = {475-487}, year = {2016}, abstract = {The bacterial endosymbiont Blochmannia floridanus of the carpenter ant Camponotus floridanus contributes to its hosts' ontogeny via nutritional upgrading during metamorphosis. This primary endosymbiosis is essential for both partners and vertical transmission of the endosymbionts is guaranteed by bacterial infestation of oocytes. Here we present a detailed analysis of the presence and localisation of B. floridanus in the ants' ovaries obtained by FISH and TEM analyses. The most apical part of the germarium harbouring germ-line stem cells (GSCs) is not infected by the bacteria. The bacteria are detectable for the first time in lower parts of the germarium when cystocytes undergo the 4th and 5th division and B. floridanus infects somatic cells lying under the basal lamina surrounding the ovarioles. With the beginning of cystocyte differentiation, the endosymbionts are exclusively transported from follicle cells into the growing oocytes. This infestation of the oocytes by bacteria very likely involves exocytosis endocytosis processes between follicle cells and the oocytes. Nurse cells were never found to harbour the endosymbionts. Furthermore we present first gene expression data in C floridanus ovaries. These data indicate a modulation of immune gene expression which may facilitate tolerance towards the endosymbionts and thus may contribute to their transovarial transmission.}, language = {en} } @article{BiscottiGerdolCanapaetal.2016, author = {Biscotti, Maria Assunta and Gerdol, Marco and Canapa, Adriana and Forconi, Mariko and Olmo, Ettore and Pallavicini, Alberto and Barucca, Marco and Schartl, Manfred}, title = {The Lungfish Transcriptome: A Glimpse into Molecular Evolution Events at the Transition from Water to Land}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {21571}, doi = {10.1038/srep21571}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167753}, year = {2016}, abstract = {Lungfish and coelacanths are the only living sarcopterygian fish. The phylogenetic relationship of lungfish to the last common ancestor of tetrapods and their close morphological similarity to their fossil ancestors make this species uniquely interesting. However their genome size, the largest among vertebrates, is hampering the generation of a whole genome sequence. To provide a partial solution to the problem, a high-coverage lungfish reference transcriptome was generated and assembled. The present findings indicate that lungfish, not coelacanths, are the closest relatives to land-adapted vertebrates. Whereas protein-coding genes evolve at a very slow rate, possibly reflecting a "living fossil" status, transposable elements appear to be active and show high diversity, suggesting a role for them in the remarkable expansion of the lungfish genome. Analyses of single genes and gene families documented changes connected to the water to land transition and demonstrated the value of the lungfish reference transcriptome for comparative studies of vertebrate evolution.}, language = {en} } @article{KuenstnerHoffmannFraseretal.2016, author = {K{\"u}nstner, Axel and Hoffmann, Margarete and Fraser, Bonnie A. and Kottler, Verena A. and Sharma, Eshita and Weigel, Detlef and Dreyer, Christine}, title = {The Genome of the Trinidadian Guppy, Poecilia reticulata, and Variation in the Guanapo Population}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {12}, doi = {10.1371/journal.pone.0169087}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166755}, pages = {e0169087}, year = {2016}, abstract = {For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-predation site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95\% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individuals. The identified 5 million SNPs correspond to an average nucleotide diversity (π) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adaptation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish.}, language = {en} } @article{DeelemanReinholdMillerFloren2016, author = {Deeleman-Reinhold, Christa L. and Miller, Jeremy and Floren, Andreas}, title = {Depreissia decipiens, an enigmatic canopy spider from Borneo revisited (Araneae, Salticidae), with remarks on the distribution and diversity of canopy spiders in Sabah, Borneo}, series = {ZooKeys}, volume = {556}, journal = {ZooKeys}, doi = {10.3897/zookeys.556.6174}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168342}, pages = {1-17}, year = {2016}, abstract = {Depreissia is a little known genus comprising two hymenopteran-mimicking species, one found in Central Africa and one in the north of Borneo. The male of D. decipiens is redescribed, the female is described for the first time. The carapace is elongated, dorsally flattened and rhombus-shaped, the rear of the thorax laterally depressed and transformed, with a pair of deep pits; the pedicel is almost as long as the abdomen. The male palp is unusual, characterized by the transverse deeply split membranous tegulum separating a ventral part which bears a sclerotized tegular apophysis and a large dagger-like retrodirected median apophysis. The female epigyne consists of one pair of large adjacent spermathecae and very long copulatory ducts arising posteriorly and rising laterally alongside the spermathecae continuing in several vertical and horizontal coils over the anterior surface. Relationships within the Salticidae are discussed and an affinity with the Cocalodinae is suggested. Arguments are provided for a hypothesis that D. decipiens is not ant-mimicking as was previously believed, but is a mimic of polistinine wasps. The species was found in the canopy in the Kinabalu area only, in primary and old secondary rainforest at 200-700 m.a.s.l. Overlap of canopy-dwelling spider species with those in the understorey are discussed and examples of species richness and endemism in the canopy are highlighted. Canopy fogging is a very efficient method of collecting for most arthropods. The canopy fauna adds an extra dimension to the known biodiversity of the tropical rainforest. In southeast Asia, canopy research has been neglected, inhibiting evaluation of comparative results of this canopy project with that from other regions. More use of fogging as a collecting method would greatly improve insight into the actual species richness and species distribution in general.}, language = {en} } @article{SchlinkertLudwigBataryetal.2016, author = {Schlinkert, Hella and Ludwig, Martin and Bat{\´a}ry, P{\´e}ter and Holzschuh, Andrea and Kov{\´a}cs-Hosty{\´a}nszki, Anik{\´o} and Tscharntke, Teja and Fischer, Christina}, title = {Forest specialist and generalist small mammals in forest edges and hedges}, series = {Wildlife Biology}, volume = {22}, journal = {Wildlife Biology}, number = {3}, doi = {10.2981/wlb.00176}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168333}, pages = {86-94}, year = {2016}, abstract = {Agricultural intensification often leads to fragmentation of natural habitats, such as forests, and thereby negatively affects forest specialist species. However, human introduced habitats, such as hedges, may counteract negative effects of forest fragmentation and increase dispersal, particularly of forest specialists. We studied effects of habitat type (forest edge versus hedge) and hedge isolation from forests (connected versus isolated hedge) in agricultural landscapes on abundance, species richness and community composition of mice, voles and shrews in forest edges and hedges. Simultaneously to these effects of forest edge/hedge type we analysed impacts of habitat structure, namely percentage of bare ground and forest edge/hedge width, on abundance, species richness and community composition of small mammals. Total abundance and forest specialist abundance (both driven by the most abundant species Myodes glareolus, bank vole) were higher in forest edges than in hedges, while hedge isolation had no effect. In contrast, abundance of habitat generalists was higher in isolated compared to connected hedges, with no effect of habitat type (forest edge versus hedge). Species richness as well as abundance of the most abundant habitat generalist Sorex araneus (common shrew), were not affected by habitat type or hedge isolation. Decreasing percentage of bare ground and increasing forest edge/hedge width was associated with increased abundance of forest specialists, while habitat structure was unrelated to species richness or abundance of any other group. Community composition was driven by forest specialists, which exceeded habitat generalist abundance in forest edges and connected hedges, while abundances were similar to each other in isolated hedges. Our results show that small mammal forest specialists prefer forest edges as habitats over hedges, while habitat generalists are able to use unoccupied ecological niches in isolated hedges. Consequently even isolated hedges can be marginal habitats for forest specialists and habitat generalists and thereby may increase regional farmland biodiversity.}, language = {en} } @article{WidmannArtingerBiesingeretal.2016, author = {Widmann, Annekathrin and Artinger, Marc and Biesinger, Lukas and Boepple, Kathrin and Peters, Christina and Schlechter, Jana and Selcho, Mareike and Thum, Andreas S.}, title = {Genetic Dissection of Aversive Associative Olfactory Learning and Memory in Drosophila Larvae}, series = {PLoS Genetics}, volume = {12}, journal = {PLoS Genetics}, number = {10}, doi = {10.1371/journal.pgen.1006378}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166672}, pages = {e1006378}, year = {2016}, abstract = {Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes—besides other forms—a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches. Compared to adult Drosophila, memory formation was only sporadically analyzed at its larval stage. Here we deconstruct the larval mnemonic organization after aversive olfactory conditioning. We show that after odor-high salt conditioning larvae form two parallel memory phases; a short lasting component that depends on cyclic adenosine 3'5'-monophosphate (cAMP) signaling and synapsin gene function. In addition, we show for the first time for Drosophila larvae an anesthesia resistant component, which relies on radish and bruchpilot gene function, protein kinase C activity, requires presynaptic output of mushroom body Kenyon cells and dopamine function. Given the numerical simplicity of the larval nervous system this work offers a unique prospect for studying memory formation of defined specifications, at full-brain scope with single-cell, and single-synapse resolution.}, language = {en} } @article{ChagtaiZillDaineseetal.2016, author = {Chagtai, Tasnim and Zill, Christina and Dainese, Linda and Wegert, Jenny and Savola, Suvi and Popov, Sergey and Mifsud, William and Vujanic, Gordan and Sebire, Neil and Le Bouc, Yves and Ambros, Peter F. and Kager, Leo and O`Sullivan, Maureen J. and Blaise, Annick and Bergeron, Christophe and Holmquist Mengelbier, Linda and Gisselsson, David and Kool, Marcel and Tytgat, Godelieve A.M. and van den Heuvel-Eibrink, Marry M. and Graf, Norbert and van Tinteren, Harm and Coulomb, Aurore and Gessler, Manfred and Williams, Richard Dafydd and Pritchard-Jones, Kathy}, title = {Gain of 1q As a Prognostic Biomarker in Wilms Tumors (WTs) Treated With Preoperative Chemotherapy in the International Society of Paediatric Oncology (SIOP) WT 2001 Trial: a SIOP Renal Tumours Biology Consortium Study}, series = {Journal of Clinical Oncology}, volume = {34}, journal = {Journal of Clinical Oncology}, number = {26}, doi = {10.1200/JCO.2015.66.0001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187478}, pages = {3195-3205}, year = {2016}, abstract = {Purpose Wilms tumor (WT) is the most common pediatric renal tumor. Treatment planning under International Society of Paediatric Oncology (SIOP) protocols is based on staging and histologic assessment of response to preoperative chemotherapy. Despite high overall survival (OS), many relapses occur in patients without specific risk factors, and many successfully treated patients are exposed to treatments with significant risks of late effects. To investigate whether molecular biomarkers could improve risk stratification, we assessed 1q status and other potential copy number biomarkers in a large WT series. Materials and Methods WT nephrectomy samples from 586 SIOP WT 2001 patients were analyzed using a multiplex ligation-dependent probe amplification (MLPA) assay that measured the copy number of 1q and other regions of interest. Results One hundred sixty-seven (28\%) of 586 WTs had 1q gain. Five-year event-free survival (EFS) was 75.0\% in patients with 1q gain (95\% CI, 68.5\% to 82.0\%) and 88.2\% in patients without gain (95\% CI, 85.0\% to 91.4\%). OS was 88.4\% with gain (95\% CI, 83.5\% to 93.6\%) and 94.4\% without gain (95\% CI, 92.1\% to 96.7\%). In univariable analysis, 1q gain was associated with poorer EFS (P<.001; hazard ratio, 2.33) and OS (P=.01; hazard ratio, 2.16). The association of 1q gain with poorer EFS retained significance in multivariable analysis adjusted for 1p and 16q loss, sex, stage, age, and histologic risk group. Gain of 1q remained associated with poorer EFS in tumor subsets limited to either intermediate-risk localized disease or nonanaplastic localized disease. Other notable aberrations associated with poorer EFS included MYCN gain and TP53 loss. Conclusion Gain of 1q is a potentially valuable prognostic biomarker in WT, in addition to histologic response to preoperative chemotherapy and tumor stage.}, language = {en} } @article{LorenzinBenaryBaluapurietal.2016, author = {Lorenzin, Francesca and Benary, Uwe and Baluapuri, Apoorva and Walz, Susanne and Jung, Lisa Anna and von Eyss, Bj{\"o}rn and Kisker, Caroline and Wolf, Jana and Eilers, Martin and Wolf, Elmar}, title = {Different promoter affinities account for specificity in MYC-dependent gene regulation}, series = {eLife}, volume = {5}, journal = {eLife}, doi = {10.7554/eLife.15161}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162913}, pages = {e15161}, year = {2016}, abstract = {Enhanced expression of the MYC transcription factor is observed in the majority of tumors. Two seemingly conflicting models have been proposed for its function: one proposes that MYC enhances expression of all genes, while the other model suggests gene-specific regulation. Here, we have explored the hypothesis that specific gene expression profiles arise since promoters differ in affinity for MYC and high-affinity promoters are fully occupied by physiological levels of MYC. We determined cellular MYC levels and used RNA- and ChIP-sequencing to correlate promoter occupancy with gene expression at different concentrations of MYC. Mathematical modeling showed that binding affinities for interactions of MYC with DNA and with core promoter-bound factors, such as WDR5, are sufficient to explain promoter occupancies observed in vivo. Importantly, promoter affinity stratifies different biological processes that are regulated by MYC, explaining why tumor-specific MYC levels induce specific gene expression programs and alter defined biological properties of cells.}, language = {en} } @article{DreschersSauppHornefetal.2016, author = {Dreschers, Stephan and Saupp, Peter and Hornef, Mathias and Prehn, Andrea and Platen, Christopher and Morschh{\"a}user, Joachim and Orlikowsky, Thorsten W.}, title = {Reduced PICD in Monocytes Mounts Altered Neonate Immune Response to Candida albicans}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0166648}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166778}, pages = {e0166648}, year = {2016}, abstract = {Background Invasive fungal infections with Candida albicans (C. albicans) occur frequently in extremely low birthweight (ELBW) infants and are associated with poor outcome. Phagocytosis of C.albicans initializes apoptosis in monocytes (phagocytosis induced cell death, PICD). PICD is reduced in neonatal cord blood monocytes (CBMO). Hypothesis Phagocytosis of C. albicans causes PICD which differs between neonatal monocytes (CBMO) and adult peripheral blood monocytes (PBMO) due to lower stimulation of TLR-mediated immune responses. Methods The ability to phagocytose C. albicans, expression of TLRs, the induction of apoptosis (assessment of sub-G1 and nick-strand breaks) were analyzed by FACS. TLR signalling was induced by agonists such as lipopolysaccharide (LPS), Pam3Cys, FSL-1 and Zymosan and blocked (neutralizing TLR2 antibodies and MYD88 inhibitor). Results Phagocytic indices of PBMO and CBMO were similar. Following stimulation with agonists and C. albicans induced up-regulation of TLR2 and consecutive phosphorylation of MAP kinase P38 and expression of TNF-α, which were stronger on PBMO compared to CBMO (p < 0.005). Downstream, TLR2 signalling initiated caspase-3-dependent PICD which was found reduced in CBMO (p < 0.05 vs PBMO). Conclusion Our data suggest direct involvement of TLR2-signalling in C. albicans-induced PICD in monocytes and an alteration of this pathway in CBMO.}, language = {en} } @article{XuHeKaiseretal.2016, author = {Xu, Li and He, Jianzheng and Kaiser, Andrea and Gr{\"a}ber, Nikolas and Schl{\"a}ger, Laura and Ritze, Yvonne and Scholz, Henrike}, title = {A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {12}, doi = {10.1371/journal.pone.0167518}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166762}, pages = {e0167518}, year = {2016}, abstract = {Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling—the serotonin transporter-in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior.}, language = {en} } @article{PfeifferKruegerMaierhoferetal.2016, author = {Pfeiffer, Susanne and Kr{\"u}ger, Jacqueline and Maierhofer, Anna and B{\"o}ttcher, Yvonne and Kl{\"o}ting, Nora and El Hajj, Nady and Schleinitz, Dorit and Sch{\"o}n, Michael R. and Dietrich, Arne and Fasshauer, Mathias and Lohmann, Tobias and Dreßler, Miriam and Stumvoll, Michael and Haaf, Thomas and Bl{\"u}her, Matthias and Kovacs, Peter}, title = {Hypoxia-inducible factor 3A gene expression and methylation in adipose tissue is related to adipose tissue dysfunction}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {27969}, doi = {10.1038/srep27969}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167662}, year = {2016}, abstract = {Recently, a genome-wide analysis identified DNA methylation of the HIF3A (hypoxia-inducible factor 3A) as strongest correlate of BMI. Here we tested the hypothesis that HIF3A mRNA expression and CpG-sites methylation in adipose tissue (AT) and genetic variants in HIF3A are related to parameters of AT distribution and function. In paired samples of subcutaneous AT (SAT) and visceral AT (VAT) from 603 individuals, we measured HIF3A mRNA expression and analyzed its correlation with obesity and related traits. In subgroups of individuals, we investigated the effects on HIF3A genetic variants on its AT expression (N = 603) and methylation of CpG-sites (N = 87). HIF3A expression was significantly higher in SAT compared to VAT and correlated with obesity and parameters of AT dysfunction (including CRP and leucocytes count). HIF3A methylation at cg22891070 was significantly higher in VAT compared to SAT and correlated with BMI, abdominal SAT and VAT area. Rs8102595 showed a nominal significant association with AT HIF3A methylation levels as well as with obesity and fat distribution. HIF3A expression and methylation in AT are fat depot specific, related to obesity and AT dysfunction. Our data support the hypothesis that HIF pathways may play an important role in the development of AT dysfunction in obesity.}, language = {en} } @article{SchwarzTamuriKultysetal.2016, author = {Schwarz, Roland F. and Tamuri, Asif U. and Kultys, Marek and King, James and Godwin, James and Florescu, Ana M. and Schultz, J{\"o}rg and Goldman, Nick}, title = {ALVIS: interactive non-aggregative visualization and explorative analysis of multiple sequence alignments}, series = {Nucleic Acids Research}, volume = {44}, journal = {Nucleic Acids Research}, number = {8}, doi = {10.1093/nar/gkw022}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166374}, pages = {e77}, year = {2016}, abstract = {Sequence Logos and its variants are the most commonly used method for visualization of multiple sequence alignments (MSAs) and sequence motifs. They provide consensus-based summaries of the sequences in the alignment. Consequently, individual sequences cannot be identified in the visualization and covariant sites are not easily discernible. We recently proposed Sequence Bundles, a motif visualization technique that maintains a one-to-one relationship between sequences and their graphical representation and visualizes covariant sites. We here present Alvis, an open-source platform for the joint explorative analysis of MSAs and phylogenetic trees, employing Sequence Bundles as its main visualization method. Alvis combines the power of the visualization method with an interactive toolkit allowing detection of covariant sites, annotation of trees with synapomorphies and homoplasies, and motif detection. It also offers numerical analysis functionality, such as dimension reduction and classification. Alvis is user-friendly, highly customizable and can export results in publication-quality figures. It is available as a full-featured standalone version (http://www.bitbucket.org/rfs/alvis) and its Sequence Bundles visualization module is further available as a web application (http://science-practice.com/projects/sequence-bundles).}, language = {en} } @article{WeisschuhMayerStrometal.2016, author = {Weisschuh, Nicole and Mayer, Anja K. and Strom, Tim M. and Kohl, Susanne and Gl{\"o}ckle, Nicola and Schubach, Max and Andreasson, Sten and Bernd, Antje and Birch, David G. and Hamel, Christian P. and Heckenlively, John R. and Jacobson, Samuel G. and Kamme, Christina and Kellner, Ulrich and Kunstmann, Erdmute and Maffei, Pietro and Reiff, Charlotte M. and Rohrschneider, Klaus and Rosenberg, Thomas and Rudolph, G{\"u}nther and V{\´a}mos, Rita and Vars{\´a}nyi, Bal{\´a}zs and Weleber, Richard G. and Wissinger, Bernd}, title = {Mutation Detection in Patients with Retinal Dystrophies Using Targeted Next Generation Sequencing}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0145951}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167398}, pages = {e0145951}, year = {2016}, abstract = {Retinal dystrophies (RD) constitute a group of blinding diseases that are characterized by clinical variability and pronounced genetic heterogeneity. The different nonsyndromic and syndromic forms of RD can be attributed to mutations in more than 200 genes. Consequently, next generation sequencing (NGS) technologies are among the most promising approaches to identify mutations in RD. We screened a large cohort of patients comprising 89 independent cases and families with various subforms of RD applying different NGS platforms. While mutation screening in 50 cases was performed using a RD gene capture panel, 47 cases were analyzed using whole exome sequencing. One family was analyzed using whole genome sequencing. A detection rate of 61\% was achieved including mutations in 34 known and two novel RD genes. A total of 69 distinct mutations were identified, including 39 novel mutations. Notably, genetic findings in several families were not consistent with the initial clinical diagnosis. Clinical reassessment resulted in refinement of the clinical diagnosis in some of these families and confirmed the broad clinical spectrum associated with mutations in RD genes.}, language = {en} } @article{HeurichZeisKuechenhoffetal.2016, author = {Heurich, Marco and Zeis, Klara and K{\"u}chenhoff, Helmut and M{\"u}ller, J{\"o}rg and Belotti, Elisa and Bufka, Luděk and Woelfing, Benno}, title = {Selective Predation of a Stalking Predator on Ungulate Prey}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0158449}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166827}, pages = {e0158449}, year = {2016}, abstract = {Prey selection is a key factor shaping animal populations and evolutionary dynamics. An optimal forager should target prey that offers the highest benefits in terms of energy content at the lowest costs. Predators are therefore expected to select for prey of optimal size. Stalking predators do not pursue their prey long, which may lead to a more random choice of prey individuals. Due to difficulties in assessing the composition of available prey populations, data on prey selection of stalking carnivores are still scarce. We show how the stalking predator Eurasian lynx (Lynx lynx) selects prey individuals based on species identity, age, sex and individual behaviour. To address the difficulties in assessing prey population structure, we confirm inferred selection patterns by using two independent data sets: (1) data of 387 documented kills of radio-collared lynx were compared to the prey population structure retrieved from systematic camera trapping using Manly's standardized selection ratio alpha and (2) data on 120 radio-collared roe deer were analysed using a Cox proportional hazards model. Among the larger red deer prey, lynx selected against adult males—the largest and potentially most dangerous prey individuals. In roe deer lynx preyed selectively on males and did not select for a specific age class. Activity during high risk periods reduced the risk of falling victim to a lynx attack. Our results suggest that the stalking predator lynx actively selects for size, while prey behaviour induces selection by encounter and stalking success rates.}, language = {en} } @article{VazeHelfrichFoerster2016, author = {Vaze, Koustubh M. and Helfrich-F{\"o}rster, Charlotte}, title = {Drosophila ezoana uses an hour-glass or highly damped circadian clock for measuring night length and inducing diapause}, series = {Physiological Entomology}, volume = {41}, journal = {Physiological Entomology}, number = {4}, doi = {10.1111/phen.12165}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204278}, pages = {378-389}, year = {2016}, abstract = {Insects inhabiting the temperate zones measure seasonal changes in day or night length to enter the overwintering diapause. Diapause induction occurs after the duration of the night exceeds a critical night length (CNL). Our understanding of the time measurement mechanisms is continuously evolving subsequent to B{\"u}nning's proposal that circadian systems play the clock role in photoperiodic time measurement (B{\"u}nning, 1936). Initially, the photoperiodic clocks were considered to be either based on circadian oscillators or on simple hour-glasses, depending on 'positive' or 'negative' responses in Nanda-Hamner and B{\"u}nsow experiments (Nanda \& Hammer, 1958; B{\"u}nsow, 1960). However, there are also species whose responses can be regarded as neither 'positive', nor as 'negative', such as the Northern Drosophila species Drosophila ezoana, which is investigated in the present study. In addition, modelling efforts show that the 'positive' and 'negative' Nanda-Hamner responses can also be provoked by circadian oscillators that are damped to different degrees: animals with highly sustained circadian clocks will respond 'positive' and those with heavily damped circadian clocks will respond 'negative'. In the present study, an experimental assay is proposed that characterizes the photoperiodic oscillators by determining the effects of non-24-h light/dark cycles (T-cycles) on critical night length. It is predicted that there is (i) a change in the critical night length as a function of T-cycle period in sustained-oscillator-based clocks and (ii) a fxed night-length measurement (i.e. no change in critical night length) in damped-oscillator-based clocks. Drosophila ezoana flies show a critical night length of approximately 7 h irrespective of T-cycle period, suggesting a damped-oscillator-based photoperiodic clock. The conclusion is strengthened by activity recordings revealing that the activity rhythm of D. ezoana flies also dampens in constant darkness.}, language = {en} } @article{BeerSteffanDewenterHaerteletal.2016, author = {Beer, Katharina and Steffan-Dewenter, Ingolf and H{\"a}rtel, Stephan and Helfrich-F{\"o}rster, Charlotte}, title = {A new device for monitoring individual activity rhythms of honey bees reveals critical effects of the social environment on behavior}, series = {Journal of Comparative Physiology A}, volume = {202}, journal = {Journal of Comparative Physiology A}, number = {8}, doi = {10.1007/s00359-016-1103-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188030}, pages = {555-565}, year = {2016}, abstract = {Chronobiological studies of individual activity rhythms in social insects can be constrained by the artificial isolation of individuals from their social context. We present a new experimental set-up that simultaneously measures the temperature rhythm in a queen-less but brood raising mini colony and the walking activity rhythms of singly kept honey bees that have indirect social contact with it. Our approach enables monitoring of individual bees in the social context of a mini colony under controlled laboratory conditions. In a pilot experiment, we show that social contact with the mini colony improves the survival of monitored young individuals and affects locomotor activity patterns of young and old bees. When exposed to conflicting Zeitgebers consisting of a light-dark (LD) cycle that is phase-delayed with respect to the mini colony rhythm, rhythms of young and old bees are socially synchronized with the mini colony rhythm, whereas isolated bees synchronize to the LD cycle. We conclude that the social environment is a stronger Zeitgeber than the LD cycle and that our new experimental set-up is well suited for studying the mechanisms of social entrainment in honey bees.}, language = {en} } @article{ThormannAhrensArmijosetal.2016, author = {Thormann, Birthe and Ahrens, Dirk and Armijos, Diego Mar{\´i}n and Peters, Marcell K. and Wagner, Thomas and W{\"a}gele, Johann W.}, title = {Exploring the Leaf Beetle Fauna (Coleoptera: Chrysomelidae) of an Ecuadorian Mountain Forest Using DNA Barcoding}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {2}, doi = {10.1371/journal.pone.0148268}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167253}, pages = {e0148268}, year = {2016}, abstract = {Background Tropical mountain forests are hotspots of biodiversity hosting a huge but little known diversity of insects that is endangered by habitat destruction and climate change. Therefore, rapid assessment approaches of insect diversity are urgently needed to complement slower traditional taxonomic approaches. We empirically compare different DNA-based species delimitation approaches for a rapid biodiversity assessment of hyperdiverse leaf beetle assemblages along an elevational gradient in southern Ecuador and explore their effect on species richness estimates. Methodology/Principal Findings Based on a COI barcode data set of 674 leaf beetle specimens (Coleoptera: Chrysomelidae) of 266 morphospecies from three sample sites in the Podocarpus National Park, we employed statistical parsimony analysis, distance-based clustering, GMYC- and PTP-modelling to delimit species-like units and compared them to morphology-based (parataxonomic) species identifications. The four different approaches for DNA-based species delimitation revealed highly similar numbers of molecular operational taxonomic units (MOTUs) (n = 284-289). Estimated total species richness was considerably higher than the sampled amount, 414 for morphospecies (Chao2) and 469-481 for the different MOTU types. Assemblages at different elevational levels (1000 vs. 2000 m) had similar species numbers but a very distinct species composition for all delimitation methods. Most species were found only at one elevation while this turnover pattern was even more pronounced for DNA-based delimitation. Conclusions/Significance Given the high congruence of DNA-based delimitation results, probably due to the sampling structure, our study suggests that when applied to species communities on a regionally limited level with high amount of rare species (i.e. ~50\% singletons), the choice of species delimitation method can be of minor relevance for assessing species numbers and turnover in tropical insect communities. Therefore, DNA-based species delimitation is confirmed as a valuable tool for evaluating biodiversity of hyperdiverse insect communities, especially when exact taxonomic identifications are missing.}, language = {en} } @article{AhmedZeeshanDandekar2016, author = {Ahmed, Zeeshan and Zeeshan, Saman and Dandekar, Thomas}, title = {Mining biomedical images towards valuable information retrieval in biomedical and life sciences}, series = {Database - The Journal of Biological Databases and Curation}, volume = {2016}, journal = {Database - The Journal of Biological Databases and Curation}, doi = {10.1093/database/baw118}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162697}, pages = {baw118}, year = {2016}, abstract = {Biomedical images are helpful sources for the scientists and practitioners in drawing significant hypotheses, exemplifying approaches and describing experimental results in published biomedical literature. In last decades, there has been an enormous increase in the amount of heterogeneous biomedical image production and publication, which results in a need for bioimaging platforms for feature extraction and analysis of text and content in biomedical images to take advantage in implementing effective information retrieval systems. In this review, we summarize technologies related to data mining of figures. We describe and compare the potential of different approaches in terms of their developmental aspects, used methodologies, produced results, achieved accuracies and limitations. Our comparative conclusions include current challenges for bioimaging software with selective image mining, embedded text extraction and processing of complex natural language queries.}, language = {en} } @article{BertChmielewskaBergmannetal.2016, author = {Bert, Bettina and Chmielewska, Justyna and Bergmann, Sven and Busch, Maximilian and Driever, Wolfgang and Finger-Baier, Karin and H{\"o}ßler, Johanna and K{\"o}hler, Almut and Leich, Nora and Misgeld, Thomas and N{\"o}ldner, Torsten and Reiher, Annegret and Schartl, Manfred and Seebach-Sproedt, Anja and Thumberger, Thomas and Sch{\"o}nfelder, Gilbert and Grune, Barbara}, title = {Considerations for a European animal welfare standard to evaluate adverse phenotypes in teleost fish}, series = {The EMBO Journal}, volume = {35}, journal = {The EMBO Journal}, number = {11}, doi = {10.15252/embj.201694448}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188783}, pages = {1151-1154}, year = {2016}, abstract = {No abstract available.}, language = {en} } @article{JahnMarkertRyuetal.2016, author = {Jahn, Martin T. and Markert, Sebastian M. and Ryu, Taewoo and Ravasi, Timothy and Stigloher, Christian and Hentschel, Ute and Moitinho-Silva, Lucas}, title = {Shedding light on cell compartmentation in the candidate phylum Poribacteria by high resolution visualisation and transcriptional profiling}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {35860}, doi = {10.1038/srep35860}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167513}, year = {2016}, abstract = {Assigning functions to uncultivated environmental microorganisms continues to be a challenging endeavour. Here, we present a new microscopy protocol for fluorescence in situ hybridisation-correlative light and electron microscopy (FISH-CLEM) that enabled, to our knowledge for the first time, the identification of single cells within their complex microenvironment at electron microscopy resolution. Members of the candidate phylum Poribacteria, common and uncultivated symbionts of marine sponges, were used towards this goal. Cellular 3D reconstructions revealed bipolar, spherical granules of low electron density, which likely represent carbon reserves. Poribacterial activity profiles were retrieved from prokaryotic enriched sponge metatranscriptomes using simulation-based optimised mapping. We observed high transcriptional activity for proteins related to bacterial microcompartments (BMC) and we resolved their subcellular localisation by combining FISH-CLEM with immunohistochemistry (IHC) on ultra-thin sponge tissue sections. In terms of functional relevance, we propose that the BMC-A region may be involved in 1,2-propanediol degradation. The FISH-IHC-CLEM approach was proven an effective toolkit to combine -omics approaches with functional studies and it should be widely applicable in environmental microbiology.}, language = {en} } @article{YadavSelvarajBenderetal.2016, author = {Yadav, Preeti and Selvaraj, Bhuvaneish T. and Bender, Florian L. P. and Behringer, Marcus and Moradi, Mehri and Sivadasan, Rajeeve and Dombert, Benjamin and Blum, Robert and Asan, Esther and Sauer, Markus and Julien, Jean-Pierre and Sendtner, Michael}, title = {Neurofilament depletion improves microtubule dynamics via modulation of Stat3/stathmin signaling}, series = {Acta Neuropathologica}, volume = {132}, journal = {Acta Neuropathologica}, number = {1}, doi = {10.1007/s00401-016-1564-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188234}, pages = {93-110}, year = {2016}, abstract = {In neurons, microtubules form a dense array within axons, and the stability and function of this microtubule network is modulated by neurofilaments. Accumulation of neurofilaments has been observed in several forms of neurodegenerative diseases, but the mechanisms how elevated neurofilament levels destabilize axons are unknown so far. Here, we show that increased neurofilament expression in motor nerves of pmn mutant mice, a model of motoneuron disease, causes disturbed microtubule dynamics. The disease is caused by a point mutation in the tubulin-specific chaperone E (Tbce) gene, leading to an exchange of the most C-terminal amino acid tryptophan to glycine. As a consequence, the TBCE protein becomes instable which then results in destabilization of axonal microtubules and defects in axonal transport, in particular in motoneurons. Depletion of neurofilament increases the number and regrowth of microtubules in pmn mutant motoneurons and restores axon elongation. This effect is mediated by interaction of neurofilament with the stathmin complex. Accumulating neurofilaments associate with stathmin in axons of pmn mutant motoneurons. Depletion of neurofilament by Nefl knockout increases Stat3-stathmin interaction and stabilizes the microtubules in pmn mutant motoneurons. Consequently, counteracting enhanced neurofilament expression improves axonal maintenance and prolongs survival of pmn mutant mice. We propose that this mechanism could also be relevant for other neurodegenerative diseases in which neurofilament accumulation and loss of microtubules are prominent features.}, language = {en} } @article{KaluzaWallaceKelleretal.2017, author = {Kaluza, Benjamin F. and Wallace, Helen and Keller, Alexander and Heard, Tim A. and Jeffers, Bradley and Drescher, Nora and Bl{\"u}thgen, Nico and Leonhardt, Sara D.}, title = {Generalist social bees maximize diversity intake in plant species-rich and resource-abundant environments}, series = {Ecosphere}, volume = {8}, journal = {Ecosphere}, number = {3}, doi = {10.1002/ecs2.1758}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171155}, pages = {e01758}, year = {2017}, abstract = {Numerous studies revealed a positive relationship between biodiversity and ecosystem functioning, suggesting that biodiverse environments may not only enhance ecosystem processes, but also benefit individual ecosystem members by, for example, providing a higher diversity of resources. Whether and how the number of available resources affects resource collection and subsequently consumers (e.g., through impacting functions associated with resources) have, however, been little investigated, although a better understanding of this relationship may help explain why the abundance and richness of many animal species typically decline with decreasing plant (resource) diversity. Using a social bee species as model (Tetragonula carbonaria), we investigated how plant species richness—recorded for study sites located in different habitats—and associated resource abundance affected the diversity and functionality (here defined as nutritional content and antimicrobial activity) of resources (i.e., pollen, nectar, and resin) collected by a generalist herbivorous consumer. The diversity of both pollen and resin collected strongly increased with increasing plant/tree species richness, while resource abundance was only positively correlated with resin diversity. These findings suggest that bees maximize resource diversity intake in (resource) diverse habitats. Collecting more diverse resources did, however, not increase their functionality, which appeared to be primarily driven by the surrounding (plant) source community in our study. In generalist herbivores, maximizing resource diversity intake may therefore primarily secure collection of sufficient amounts of resources across the entire foraging season, but it also ensures that the allocated resources meet all functional needs. Decreasing available resource diversity may thus impact consumers primarily by reduced resource abundance, but also by reduced resource functionality, particularly when resources of high functionality (e.g., from specific plant species) become scarce.}, language = {en} } @article{DegenHovestadtMitesseretal.2017, author = {Degen, Tobias and Hovestadt, Thomas and Mitesser, Oliver and H{\"o}lker, Franz}, title = {Altered sex-specific mortality and female mating success: ecological effects and evolutionary responses}, series = {Ecosphere}, volume = {8}, journal = {Ecosphere}, number = {5}, doi = {10.1002/ecs2.1820}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170953}, pages = {e01820}, year = {2017}, abstract = {Theory predicts that males and females should often join the mating pool at different times (sexual dimorphism in timing of emergence [SDT]) as the degree of SDT affects female mating success. We utilize an analytical model to explore (1) how important SDT is for female mating success, (2) how mating success might change if either sex's mortality (abruptly) increases, and (3) to what degree evolutionary responses in SDT may be able to mitigate the consequences of such mortality increase. Increasing male pre-mating mortality has a non-linear effect on the fraction of females mated: The effect is initially weak, but at some critical level a further increase in male mortality has a stronger effect than a similar increase in female mortality. Such a change is expected to impose selection for reduced SDT. Increasing mortality during the mating season has always a stronger effect on female mating success if the mortality affects the sex that emerges first. This bias results from the fact that enhancing mortality of the earlier emerging sex reduces female-male encounter rates. However, an evolutionary response in SDT may effectively mitigate such consequences. Further, if considered independently for females and males, the predicted evolutionary response in SDT could be quite dissimilar. The difference between female and male evolutionary response in SDT leads to marked differences in the fraction of fertilized females under certain conditions. Our model may provide general guidelines for improving harvesting of populations, conservation management of rare species under altered environmental conditions, or maintaining long-term efficiency of pest-control measures.}, language = {en} } @article{ZieglerWeissSchmittetal.2017, author = {Ziegler, Sabrina and Weiss, Esther and Schmitt, Anna-Lena and Schlegel, Jan and Burgert, Anne and Terpitz, Ulrich and Sauer, Markus and Moretta, Lorenzo and Sivori, Simona and Leonhardt, Ines and Kurzai, Oliver and Einsele, Hermann and Loeffler, Juergen}, title = {CD56 Is a Pathogen Recognition Receptor on Human Natural Killer Cells}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {6138}, doi = {10.1038/s41598-017-06238-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170637}, year = {2017}, abstract = {Aspergillus (A.) fumigatus is an opportunistic fungal mold inducing invasive aspergillosis (IA) in immunocompromised patients. Although antifungal activity of human natural killer (NK) cells was shown in previous studies, the underlying cellular mechanisms and pathogen recognition receptors (PRRs) are still unknown. Using flow cytometry we were able to show that the fluorescence positivity of the surface receptor CD56 significantly decreased upon fungal contact. To visualize the interaction site of NK cells and A. fumigatus we used SEM, CLSM and dSTORM techniques, which clearly demonstrated that NK cells directly interact with A. fumigatus via CD56 and that CD56 is re-organized and accumulated at this interaction site time-dependently. The inhibition of the cytoskeleton showed that the receptor re-organization was an active process dependent on actin re-arrangements. Furthermore, we could show that CD56 plays a role in the fungus mediated NK cell activation, since blocking of CD56 surface receptor reduced fungal mediated NK cell activation and reduced cytokine secretion. These results confirmed the direct interaction of NK cells and A. fumigatus, leading to the conclusion that CD56 is a pathogen recognition receptor. These findings give new insights into the functional role of CD56 in the pathogen recognition during the innate immune response.}, language = {en} } @article{KollmannsbergerKerschnitzkiReppetal.2017, author = {Kollmannsberger, Philip and Kerschnitzki, Michael and Repp, Felix and Wagermaier, Wolfgang and Weinkamer, Richard and Fratzl, Peter}, title = {The small world of osteocytes: connectomics of the lacuno-canalicular network in bone}, series = {New Journal of Physics}, volume = {19}, journal = {New Journal of Physics}, number = {073019}, doi = {10.1088/1367-2630/aa764b}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170662}, year = {2017}, abstract = {Osteocytes and their cell processes reside in a large, interconnected network of voids pervading the mineralized bone matrix of most vertebrates. This osteocyte lacuno-canalicular network (OLCN) is believed to play important roles in mechanosensing, mineral homeostasis, and for the mechanical properties of bone. While the extracellular matrix structure of bone is extensively studied on ultrastructural and macroscopic scales, there is a lack of quantitative knowledge on how the cellular network is organized. Using a recently introduced imaging and quantification approach, we analyze the OLCN in different bone types from mouse and sheep that exhibit different degrees of structural organization not only of the cell network but also of the fibrous matrix deposited by the cells. We define a number of robust, quantitative measures that are derived from the theory of complex networks. These measures enable us to gain insights into how efficient the network is organized with regard to intercellular transport and communication. Our analysis shows that the cell network in regularly organized, slow-growing bone tissue from sheep is less connected, but more efficiently organized compared to irregular and fast-growing bone tissue from mice. On the level of statistical topological properties (edges per node, edge length and degree distribution), both network types are indistinguishable, highlighting that despite pronounced differences at the tissue level, the topological architecture of the osteocyte canalicular network at the subcellular level may be independent of species and bone type. Our results suggest a universal mechanism underlying the self-organization of individual cells into a large, interconnected network during bone formation and mineralization.}, language = {en} } @article{MemmelSisarioZoelleretal.2017, author = {Memmel, Simon and Sisario, Dmitri and Z{\"o}ller, Caren and Fiedler, Vanessa and Katzer, Astrid and Heiden, Robin and Becker, Nicholas and Eing, Lorenz and Ferreira, F{\´a}bio L.R. and Zimmermann, Heiko and Sauer, Markus and Flentje, Michael and Sukhorukov, Vladimir L. and Djuzenova, Cholpon S.}, title = {Migration pattern, actin cytoskeleton organization and response to PI3K-, mTOR-, and Hsp90-inhibition of glioblastoma cells with different invasive capacities}, series = {Oncotarget}, volume = {8}, journal = {Oncotarget}, number = {28}, doi = {10.18632/oncotarget.16847}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170719}, pages = {45298-45310}, year = {2017}, abstract = {High invasiveness and resistance to chemo- and radiotherapy of glioblastoma multiforme (GBM) make it the most lethal brain tumor. Therefore, new treatment strategies for preventing migration and invasion of GBM cells are needed. Using two different migration assays, Western blotting, conventional and super-resolution (dSTORM) fluorescence microscopy we examine the effects of the dual PI3K/mTOR-inhibitor PI-103 alone and in combination with the Hsp90 inhibitor NVP-AUY922 and/or irradiation on the migration, expression of marker proteins, focal adhesions and F-actin cytoskeleton in two GBM cell lines (DK-MG and SNB19) markedly differing in their invasive capacity. Both lines were found to be strikingly different in morphology and migration behavior. The less invasive DK-MG cells maintained a polarized morphology and migrated in a directionally persistent manner, whereas the highly invasive SNB19 cells showed a multipolar morphology and migrated randomly. Interestingly, a single dose of 2 Gy accelerated wound closure in both cell lines without affecting their migration measured by single-cell tracking. PI-103 inhibited migration of DK-MG (p53 wt, PTEN wt) but not of SNB19 (p53 mut, PTEN mut) cells probably due to aberrant reactivation of the PI3K pathway in SNB19 cells treated with PI-103. In contrast, NVP-AUY922 exerted strong anti-migratory effects in both cell lines. Inhibition of cell migration was associated with massive morphological changes and reorganization of the actin cytoskeleton. Our results showed a cell line-specific response to PI3K/mTOR inhibition in terms of GBM cell motility. We conclude that anti-migratory agents warrant further preclinical investigation as potential therapeutics for treatment of GBM.}, language = {en} } @phdthesis{Borst2017, author = {Borst, Andreas}, title = {Apoptosis \& senescence: cell fate determination in inhibitor-treated melanoma cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-155085}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {Neoplasms of the skin represent the most frequent tumors worldwide; fortunately, most of them are benign or semi-malignant and well treatable. However, the two most aggressive and deadly forms of malignant skin-neoplasms are melanoma and Merkel cell carcinoma (MCC), being responsible for more than 90\% of skin-cancer related deaths. The last decade has yielded enormous progress in melanoma therapy with the advent of targeted therapies, like BRAF or MEK inhibitors, and immune-stimulating therapies, using checkpoint antibodies targeting CTLA- 4, PD-1 or PD-L1. Very recent studies suggest that also MCC patients benefit from a treatment with checkpoint antibodies. Nevertheless, in an advanced metastatic stage, a cure for both of these aggressive malignancies is still hard to achieve: while only a subset of patients experience durable benefit from the immune-based therapies, the widely applicable targeted therapies struggle with development of resistances that inevitably occur in most patients, and finally lead to their death. The four articles included in this thesis addressed current questions concerning therapy and carcinogenesis of melanoma and MCC. Moreover, they are discussed in the light of the up-to-date research regarding targeted and immune-based therapies. In article I we demonstrated that besides apoptosis, MAPK pathway inhibition in BRAF-mutated melanoma cells also induces senescence, a permanent cell cycle arrest. These cells may provide a source for relapse, as even permanently arrested cancer cells can contribute to a pro-tumorigenic milieu. To identify molecular factors determining the differential response, we established M14 melanoma cell line derived single cell clones that either undergo cell death or arrest when treated with BRAF/MEK inhibitors. Using these single cell clones, we demonstrated in article IV that downregulation of the pro-apoptotic BH3-only protein BIK via epigenetic silencing is involved in apoptosis deficiency, which can be overcome by HDAC inhibitors. These observations provide a possible explanation for the lack of a complete and durable response to MAPK inhibitor treatment in melanoma patients, and suggest the application of HDAC inhibitors as a complimentary therapy to MAPK pathway inhibition. Concerning MCC, we scrutinized the interactions between the Merkel cell polyomavirus' (MCV) T antigens (TA) and the tumor suppressors p53 and Rb in article II and III, respectively. In article III, we demonstrated that the cell cycle master regulator Rb is the crucial target of MCV large T (LT), while it - in contrast to other polyomavirus LTs - exhibits much lower affinity to the related proteins p107 and p130. Knockdown of MCV LT led to proliferation arrest in MCC cells, which can be rescued by knockdown of Rb, but not by knockdown of p107 and p130. Contrary to Rb, restriction of p53 in MCC seems to be independent of the MCV TAs, as we demonstrated in article II. In conclusion, the presented thesis has revealed new molecular details, regarding the response of melanoma cells towards an important treatment modality and the mechanisms of viral carcinogenesis in MCC.}, subject = {Melanom}, language = {en} } @phdthesis{Hagen2017, author = {Hagen, Franziska}, title = {Sphingolipids in gonococcal infection}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-153852}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea, has the potential to spread in the human host and cause a severe complication called disseminated gonococcal infection (DGI). The expression of the major outer membrane porin PorBIA is a characteristic of most gonococci associated with DGI. PorBIA binds to the scavenger receptor expressed on endothelial cells (SREC-I), which mediates the so-called low phosphate-dependent invasion (LPDI). This uptake mechanism enables N. gonorrhoeae to rapidly invade epithelial and endothelial cells in a phosphate-sensitive manner. We recently demonstrated that the neutral sphingomyelinase, which catalyses the hydrolysis of sphingomyelin to ceramide and phosphorylcholine, is required for the LPDI of gonococci in non-phagocytic cells. Neutral sphingomyelinase 2 (NSM2) plays a key role in the early PorBIA signaling by recruiting the PI3 kinase to caveolin. The following activation of the PI3 kinase-dependent downstream signaling leads to the engulfment of the bacteria. As a part of this work, I could confirm the involvement of the NSM2. The role of the enzyme was further elucidated by the generation of antibodies directed against NSM2 and the construction of an epithelium-based NSM2 knockout cell line using CRISPR/Cas9. The knockout of the NSM2 strongly inhibits the LPDI. The invasion could be, however, restored by the complementation of the knockout using an NSM2-GFP construct. However, the results could not be reproduced. In this work, I could show the involvement of further members of the sphingolipid pathway in the PorBIA-mediated invasion. Lipidome analysis revealed an increase of the bioactive molecules ceramide and sphingosine due to gonococcal infection. Both molecules do not only affect the host cell, but seem to influence the bacteria as well: while ceramide seems to be incorporated by the gonococci, sphingosine is toxic for the bacteria. Furthermore, the sphingosine kinase 2 (SPHK2) plays an important role in invasion, since the inhibition and knockdown of the enzyme revealed a negative effect on gonococcal invasion. To elucidate the role of the sphingosine kinases in invasion in more detail, an activity assay was established in this study. Additionally, the impact of the sphingosine-1-phosphate lyase (S1PL) on invasion was investigated. Inhibitor studies and infection experiments conducted with a CRISPR/Cas9 HeLa S1PL knockout cell line revealed a role of the enzyme not only in the PorBIA-mediated invasion, but also in the Opa50/HSPG-mediated gonococcal invasion. The signaling experiments allowed the categorization of the SPHK and S1PL activation in the context of infection. Like the NSM2, both enzymes play a role in the early PorBIA signaling events leading to the uptake of the bacteria. All those findings indicate an important role of sphingolipids in the invasion and survival of N. gonorrhoeae. In the last part of this work, the role of the NSM2 in the inhibition of apoptosis in neutrophils due to gonococcal infection was investigated. It could be demonstrated that the delayed onset of apoptosis is independent of neisserial porin and Opa proteins. Furthermore, the influence of neisserial peptidoglycan on PMN apoptosis was analysed using mutant strains, but no connection could be determined. Since the NSM2 is the most prominent sphingomyelinase in PMNs, fulfils manifold cell physiological functions and has already been connected to apoptosis, the impact of the enzyme on apoptosis inhibition due to gonococcal infection was investigated using inhibitors, with no positive results.}, subject = {gonococcal}, language = {en} } @phdthesis{Reis2017, author = {Reis, Helena}, title = {Characterization of telomere protein complexes in Trypanosoma brucei}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151323}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {African trypanosomiasis is a disease endemic to sub-Saharan Africa. It affects humans as well as wild and domestic animals. The human form of the disease is known as sleeping sickness and the animal form as nagana, which are usually fatal if left untreated. The cause of African trypanosomiasis is the unicellular parasite Trypanosoma brucei. During its life cycle, Trypanosoma brucei shuttles between a mammalian host and the tsetse fly vector. In the mammalian host the parasite multiplies as bloodstream form (BSF) extracellularly in the bloodstream or the lymphatic system. Survival of BSF parasites relies on immune evasion by antigenic variation of surface proteins because its extracellular lifestyle leads to direct exposure to immune responses. At any given time each BSF cell expresses a single type of variant surface glycoprotein (VSG) on its surface from a large repertoire. The active VSG is transcribed from one of 15 specialized subtelomeric domains, termed bloodstream expression sites (BESs). The remaining 14 BESs are silenced. This monoallelic expression and periodic switching of the expressed VSG enables to escape the immune response and to establish a persistent infection in the mammalian host. During developmental differentiation from BSF to the insect vector-resident procyclic form (PCF), the active BES is transcriptionally silenced to stop VSG transcription. Thus, all 15 BESs are inactive in the PCF cells as surface protein expression is developmentally regulated. Previous reports have shown that the telomere complex components TbTRF, TbRAP1 and TbTIF2 are involved in VSG transcriptional regulation. However, the precise nature of their contribution remains unclear. In addition, no information is available about the role of telomeres in the initiation and regulation of developmental BES silencing. To gain insights into the regulatory mechanisms of telomeres on VSG transcription and developmental repression it is therefore essential to identify the complete composition of the trypanosome telomere complex. To this end, we used two complementary biochemical approaches and quantitative label-free interactomics to determine the composition of telomere protein complexes in T. brucei. Firstly, using a telomeric pull-down assay we found 17 potential telomere-binding proteins including the known telomere-binding proteins TbTRF and TbTIF2. Secondly, by performing a co-immunoprecipitation experiment to elucidate TbTRF interactions we co-purified five proteins. All of these five proteins were also enriched with telomeric DNA in the pull-down assay. To validate these data, I characterized one of the proteins found in both experiments (TelBP1). In BSF cells, TelBP1 co-localizes with TbTRF and interacts with already described telomere-binding proteins such as TbTRF, TbTIF2 and TbRAP1 indicating that TelBP1 is a novel component of the telomere complex in trypanosomes. Interestingly, protein interaction studies in PCF cells suggested a different telomere complex composition compared to BSF cells. In contrast to known members of the telomere complex, TelBP1 is dispensable for cell viability indicating that its function might be uncoupled from the known telomere-binding proteins. Overexpression of TelBP1 had also no effect on cell viability, but led to the discovery of two additional shorter isoforms of TelBP1. However, their source and function remained elusive. Although TelBP1 is not essential for cell viability, western blot analysis revealed a 4-fold upregulation of TelBP1 in the BSF stage compared to the PCF stage supporting the concept of a dynamic telomere complex composition. We observed that TelBP1 influences the kinetics of transcriptional BES silencing during developmental transition from BSF to PCF. Deletion of TelBP1 caused faster BES silencing compared to wild-type parasites. Taken together, TelBP1 function illustrates that developmental BES silencing is a fine-tuned process, which involves stage-specific changes in telomere complex formation.}, subject = {Trypanosoma brucei}, language = {en} }