TY - JOUR A1 - Lichthardt, Sven A1 - Wagner, Johanna A1 - Löb, Stefan A1 - Matthes, Niels A1 - Kastner, Caroline A1 - Anger, Friedrich A1 - Germer, Christoph-Thomas A1 - Wiegering, Armin T1 - Pathological complete response due to a prolonged time interval between preoperative chemoradiation and surgery in locally advanced rectal cancer: analysis from the German StuDoQ|Rectalcarcinoma registry JF - BMC Cancer N2 - Background Preoperative chemoradiotherapy is the recommended standard of care for patients with local advanced rectal cancer. However, it remains unclear, whether a prolonged time interval to surgery results in an increased perioperative morbidity, reduced TME quality or better pathological response. Aim of this study was to determine the time interval for best pathological response and perioperative outcome compared to current recommended interval of 6 to 8 weeks. Methods This is a retrospective analysis of the German StuDoQ|Rectalcarcinoma registry. Patients were grouped for the time intervals of "less than 6 weeks", "6 to 8 weeks", "8 to 10 weeks" and "more than 10 weeks". Primary endpoint was pathological response, secondary endpoint TME quality and complications according to Clavien-Dindo classification. Results Due to our inclusion criteria (preoperative chemoradiation, surgery in curative intention, M0), 1.809 of 9.560 patients were suitable for analysis. We observed a trend for increased rates of pathological complete response (pCR: ypT0ypN0) and pathological good response (pGR: ypT0-1ypN0) for groups with a prolonged time interval which was not significant. Ultimately, it led to a steady state of pCR (16.5%) and pGR (22.6%) in "8 to 10" and "more than 10" weeks. We were not able to observe any differences between the subgroups in perioperative morbidity, proportion of rectal extirpation (for cancer of the lower third) or difference in TME quality. Conclusion A prolonged time interval between neoadjuvant chemoradiation can be performed, as the rate of pCR seems to be increased without influencing perioperative morbidity. KW - Rectal cancer KW - Surgery KW - Radiochemotherapy KW - Time interval Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229334 VL - 20 IS - 1 ER - TY - JOUR A1 - Götz, Ralph A1 - Panzer, Sabine A1 - Trinks, Nora A1 - Eilts, Janna A1 - Wagener, Johannes A1 - Turrà, David A1 - Di Pietro, Antonio A1 - Sauer, Markus A1 - Terpitz, Ulrich T1 - Expansion Microscopy for Cell Biology Analysis in Fungi JF - Frontiers in Microbiology N2 - Super-resolution microscopy has evolved as a powerful method for subdiffraction-resolution fluorescence imaging of cells and cellular organelles, but requires sophisticated and expensive installations. Expansion microscopy (ExM), which is based on the physical expansion of the cellular structure of interest, provides a cheap alternative to bypass the diffraction limit and enable super-resolution imaging on a conventional fluorescence microscope. While ExM has shown impressive results for the magnified visualization of proteins and RNAs in cells and tissues, it has not yet been applied in fungi, mainly due to their complex cell wall. Here we developed a method that enables reliable isotropic expansion of ascomycetes and basidiomycetes upon treatment with cell wall degrading enzymes. Confocal laser scanning microscopy (CLSM) and structured illumination microscopy (SIM) images of 4.5-fold expanded sporidia of Ustilago maydis expressing fluorescent fungal rhodopsins and hyphae of Fusarium oxysporum or Aspergillus fumigatus expressing either histone H1-mCherry together with Lifeact-sGFP or mRFP targeted to mitochondria, revealed details of subcellular structures with an estimated spatial resolution of around 30 nm. ExM is thus well suited for cell biology studies in fungi on conventional fluorescence microscopes. KW - Expansion microscopy KW - fluorescence microscopy KW - fungi KW - sporidia KW - hyphae Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202569 SN - 1664-302X VL - 11 ER - TY - JOUR A1 - Vikuk, Veronika A1 - Fuchs, Benjamin A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Rueb, Selina A1 - Krauss, Jochen T1 - Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany? JF - Journal of Fungi N2 - Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable. KW - Epichloë KW - Lolium perenne KW - toxicity KW - grasslands KW - HPLC/UPLC methods KW - endophyte KW - plant fresh/dry weight KW - alkaloid detection methods KW - mycotoxins KW - phenology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213171 SN - 2309-608X VL - 6 IS - 3 ER - TY - JOUR A1 - Osman, Mohamed A1 - Stigloher, Christian A1 - Mueller, Martin J. A1 - Waller, Frank T1 - An improved growth medium for enhanced inoculum production of the plant growth-promoting fungus Serendipita indica JF - Plant Methods N2 - Background The plant endophytic fungus Serendipita indica colonizes roots of a wide range of plant species and can enhance growth and stress resistance of these plants. Due to its ease of axenic cultivation and its broad host plant range including the model plant Arabidopsis thaliana and numerous crop plants, it is widely used as a model fungus to study beneficial fungus-root interactions. In addition, it was suggested to be utilized for commercial applications, e.g. to enhance yield in barley and other species. To produce inoculum, S. indica is mostly cultivated in a complex Hill-Kafer medium (CM medium), however, growth in this medium is slow, and yield of chlamydospores, which are often used for plant root inoculation, is relatively low. Results We tested and optimized a simple vegetable juice-based medium for an enhanced yield of fungal inoculum. The described vegetable juice (VJ) medium is based on commercially available vegetable juice and is easy to prepare. VJ medium was superior to the currently used CM medium with respect to biomass production in liquid medium and hyphal growth on agar plates. Using solid VJ medium supplemented with sucrose (VJS), a high amount of chlamydospores developed already after 8 days of cultivation, producing significantly more spores than on CM medium. Use of VJ medium is not restricted to S. indica, as it also supported growth of two pathogenic fungi often used in plant pathology experiments: the ascomycete Fusarium graminearum, the causal agent of Fusarium head blight disease on wheat and barley, and Verticillium longisporum, the causal agent of verticillium wilt. Conclusions The described VJ medium is recommended for streamlined and efficient production of inoculum for the plant endophytic fungus Serendipita indica and might prove superior for the propagation of other fungi for research purposes. KW - Serendipita indica KW - Plant root endophyte KW - Inoculum production KW - Complex medium KW - Aspergillus medium KW - Vegetable juice KW - Plant growth promotion Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229186 VL - 16 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Bencurova, Elena A1 - Förster, Carola A1 - Dandekar, Thomas T1 - Modeling of shotgun sequencing of DNA plasmids using experimental and theoretical approaches JF - BMC Bioinformatics N2 - Background Processing and analysis of DNA sequences obtained from next-generation sequencing (NGS) face some difficulties in terms of the correct prediction of DNA sequencing outcomes without the implementation of bioinformatics approaches. However, algorithms based on NGS perform inefficiently due to the generation of long DNA fragments, the difficulty of assembling them and the complexity of the used genomes. On the other hand, the Sanger DNA sequencing method is still considered to be the most reliable; it is a reliable choice for virtual modeling to build all possible consensus sequences from smaller DNA fragments. Results In silico and in vitro experiments were conducted: (1) to implement and test our novel sequencing algorithm, using the standard cloning vectors of different length and (2) to validate experimentally virtual shotgun sequencing using the PCR technique with the number of cycles from 1 to 9 for each reaction. Conclusions We applied a novel algorithm based on Sanger methodology to correctly predict and emphasize the performance of DNA sequencing techniques as well as in de novo DNA sequencing and its further application in synthetic biology. We demonstrate the statistical significance of our results. KW - Shotgun method KW - Sanger sequencing KW - Virtual sequencing KW - Polymerase chain reaction KW - Gene expression vectors KW - Synthetic biology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229169 VL - 2020 ER - TY - JOUR A1 - Seitz, Nicola A1 - vanEngelsdorp, Dennis A1 - Leonhardt, Sara D. T1 - Are native and non‐native pollinator friendly plants equally valuable for native wild bee communities? JF - Ecology and Evolution N2 - Bees rely on floral pollen and nectar for food. Therefore, pollinator friendly plantings are often used to enrich habitats in bee conservation efforts. As part of these plantings, non‐native plants may provide valuable floral resources, but their effects on native bee communities have not been assessed in direct comparison with native pollinator friendly plantings. In this study, we performed a common garden experiment by seeding mixes of 20 native and 20 non‐native pollinator friendly plant species at separate neighboring plots at three sites in Maryland, USA, and recorded flower visitors for 2 years. A total of 3,744 bees (120 species) were collected. Bee abundance and species richness were either similar across plant types (midseason and for abundance also late season) or lower at native than at non‐native plots (early season and for richness also late season). The overall bee community composition differed significantly between native and non‐native plots, with 11 and 23 bee species being found exclusively at one plot type or the other, respectively. Additionally, some species were more abundant at native plant plots, while others were more abundant at non‐natives. Native plants hosted more specialized plant–bee visitation networks than non‐native plants. Three species out of the five most abundant bee species were more specialized when foraging on native plants than on non‐native plants. Overall, visitation networks were more specialized in the early season than in late seasons. Our findings suggest that non‐native plants can benefit native pollinators, but may alter foraging patterns, bee community assemblage, and bee–plant network structures. KW - bee conservation KW - common garden experiment KW - exotic plants KW - non‐native plants KW - plant–bee visitation networks KW - pollinator friendly plants KW - wild bees Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218439 VL - 10 IS - 23 ER - TY - JOUR A1 - Bowler, Diana E. A1 - Bjorkman, Anne D. A1 - Dornelas, Maria A1 - Myers‐Smith, Isla H. A1 - Navarro, Laetitia M. A1 - Niamir, Aidin A1 - Supp, Sarah R. A1 - Waldock, Conor A1 - Winter, Marten A1 - Vellend, Mark A1 - Blowes, Shane A. A1 - Böhning‐Gaese, Katrin A1 - Bruelheide, Helge A1 - Elahi, Robin A1 - Antão, Laura H. A1 - Hines, Jes A1 - Isbell, Forest A1 - Jones, Holly P. A1 - Magurran, Anne E. A1 - Cabral, Juliano Sarmento A1 - Bates, Amanda E. T1 - Mapping human pressures on biodiversity across the planet uncovers anthropogenic threat complexes JF - People and Nature N2 - Climate change and other anthropogenic drivers of biodiversity change are unequally distributed across the world. Overlap in the distributions of different drivers have important implications for biodiversity change attribution and the potential for interactive effects. However, the spatial relationships among different drivers and whether they differ between the terrestrial and marine realm has yet to be examined. We compiled global gridded datasets on climate change, land‐use, resource exploitation, pollution, alien species potential and human population density. We used multivariate statistics to examine the spatial relationships among the drivers and to characterize the typical combinations of drivers experienced by different regions of the world. We found stronger positive correlations among drivers in the terrestrial than in the marine realm, leading to areas with high intensities of multiple drivers on land. Climate change tended to be negatively correlated with other drivers in the terrestrial realm (e.g. in the tundra and boreal forest with high climate change but low human use and pollution), whereas the opposite was true in the marine realm (e.g. in the Indo‐Pacific with high climate change and high fishing). We show that different regions of the world can be defined by Anthropogenic Threat Complexes (ATCs), distinguished by different sets of drivers with varying intensities. We identify 11 ATCs that can be used to test hypotheses about patterns of biodiversity and ecosystem change, especially about the joint effects of multiple drivers. Our global analysis highlights the broad conservation priorities needed to mitigate the impacts of anthropogenic change, with different priorities emerging on land and in the ocean, and in different parts of the world. KW - Anthropocene KW - biodiversity threats KW - direct drivers KW - global change Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213634 VL - 2 IS - 2 SP - 380 EP - 394 ER - TY - JOUR A1 - Gupta, Shishir K. A1 - Srivastava, Mugdha A1 - Osmanoglu, Oezge A1 - Dandekar, Thomas T1 - Genome-wide inference of the Camponotus floridanus protein-protein interaction network using homologous mapping and interacting domain profile pairs JF - Scientific Reports N2 - Apart from some model organisms, the interactome of most organisms is largely unidentified. High-throughput experimental techniques to determine protein-protein interactions (PPIs) are resource intensive and highly susceptible to noise. Computational methods of PPI determination can accelerate biological discovery by identifying the most promising interacting pairs of proteins and by assessing the reliability of identified PPIs. Here we present a first in-depth study describing a global view of the ant Camponotus floridanus interactome. Although several ant genomes have been sequenced in the last eight years, studies exploring and investigating PPIs in ants are lacking. Our study attempts to fill this gap and the presented interactome will also serve as a template for determining PPIs in other ants in future. Our C. floridanus interactome covers 51,866 non-redundant PPIs among 6,274 proteins, including 20,544 interactions supported by domain-domain interactions (DDIs), 13,640 interactions supported by DDIs and subcellular localization, and 10,834 high confidence interactions mediated by 3,289 proteins. These interactions involve and cover 30.6% of the entire C. floridanus proteome. KW - interaction map KW - drosophila KW - identification KW - evolutionary KW - reliability KW - annotation KW - database KW - target KW - cycle Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229406 VL - 10 IS - 1 ER - TY - JOUR A1 - De Lira, Maria Nathalia A1 - Raman, Sudha Janaki A1 - Schulze, Almut A1 - Schneider-Schaulies, Sibylle A1 - Avota, Elita T1 - Neutral Sphingomyelinase-2 (NSM 2) Controls T Cell Metabolic Homeostasis and Reprogramming During Activation JF - Frontiers in Molecular Biosciences N2 - Neutral sphingomyelinase-2 (NSM2) is a member of a superfamily of enzymes responsible for conversion of sphingomyelin into phosphocholine and ceramide at the cytosolic leaflet of the plasma membrane. Upon specific ablation of NSM2, T cells proved to be hyper-responsive to CD3/CD28 co-stimulation, indicating that the enzyme acts to dampen early overshooting activation of these cells. It remained unclear whether hyper-reactivity of NSM2-deficient T cells is supported by a deregulated metabolic activity in these cells. Here, we demonstrate that ablation of NSM2 activity affects metabolism of the quiescent CD4\(^+\) T cells which accumulate ATP in mitochondria and increase basal glycolytic activity. This supports enhanced production of total ATP and metabolic switch early after TCR/CD28 stimulation. Most interestingly, increased metabolic activity in resting NSM2-deficient T cells does not support sustained response upon stimulation. While elevated under steady-state conditions in NSM2-deficient CD4\(^+\) T cells, the mTORC1 pathway regulating mitochondria size, oxidative phosphorylation, and ATP production is impaired after 24 h of stimulation. Taken together, the absence of NSM2 promotes a hyperactive metabolic state in unstimulated CD4\(^+\) T cells yet fails to support sustained T cell responses upon antigenic stimulation. KW - neutral sphingomyelinase-2 KW - T cell receptor KW - Seahorse XF KW - oxidative phosphorylation KW - ATP-adenosine triphosphate KW - Mitochondria Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211311 SN - 2296-889X VL - 7 ER - TY - JOUR A1 - Vogel, Sebastian A1 - Gossner, Martin M. A1 - Mergner, Ulrich A1 - Müller, Jörg A1 - Thorn, Simon T1 - Optimizing enrichment of deadwood for biodiversity by varying sun exposure and tree species: An experimental approach JF - Journal of Applied Ecology N2 - The enrichment of deadwood is essential for the conservation of saproxylic biodiversity in managed forests. However, existing strategies focus on a cost‐intensive increase of deadwood amount, while largely neglecting increasing deadwood diversity. Deadwood objects, that is logs and branches, from six tree species were experimentally sun exposed, canopy shaded and artificially shaded for 4 years, after which the alpha‐, beta‐ and gamma‐diversity of saproxylic beetles, wood‐inhabiting fungi and spiders were analysed. Analyses of beta‐diversity included the spatial distance between exposed deadwood objects. A random‐drawing procedure was used to identify the combination of tree species and sun exposure that yielded the highest gamma‐diversity at a minimum of exposed deadwood amount. In sun‐exposed plots, species numbers in logs were higher than in shaded plots for all taxa, while in branches we observed the opposite for saproxylic beetles. Tree species affected the species numbers only of saproxylic beetles and wood‐inhabiting fungi. The beta‐diversity of saproxylic beetles and wood‐inhabiting fungi among logs was influenced by sun exposure and tree species, but beta‐diversity of spiders by sun exposure only. For all saproxylic taxa recorded in logs, differences between communities increased with increasing spatial distance. A combination of canopy‐shaded Carpinus logs and sun‐exposed Populus logs resulted in the highest species numbers of all investigated saproxylic taxa among all possible combinations of tree species and sun‐exposure treatments. Synthesis and applications. We recommend incorporating the enrichment of different tree species and particularly the variation in sun exposure into existing strategies of deadwood enrichment. Based on the results of our study, we suggest to combine the logs of softwood broadleaf tree species (e.g. Carpinus, Populus), hardwood broadleaf tree species (e.g. Quercus) and coniferous tree species (e.g. Pinus) under different conditions of sun exposure and distribute them spatially in a landscape to maximize the beneficial effects on overall diversity. KW - broadleaf tree species KW - deadwood enrichment KW - forest conservation KW - forest management KW - saproxylic beetles KW - spiders KW - sun exposure KW - wood‐inhabiting fungi Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214614 VL - 57 IS - 10 SP - 2075 EP - 2085 ER - TY - JOUR A1 - Müller, Jörg A1 - Ulyshen, Mike A1 - Seibold, Sebastian A1 - Cadotte, Marc A1 - Chao, Anne A1 - Bässler, Claus A1 - Vogel, Sebastian A1 - Hagge, Jonas A1 - Weiß, Ingmar A1 - Baldrian, Petr A1 - Tláskal, Vojtěch A1 - Thorn, Simon T1 - Primary determinants of communities in deadwood vary among taxa but are regionally consistent JF - Oikos N2 - The evolutionary split between gymnosperms and angiosperms has far‐reaching implications for the current communities colonizing trees. The inherent characteristics of dead wood include its role as a spatially scattered habitat of plant tissue, transient in time. Thus, local assemblages in deadwood forming a food web in a necrobiome should be affected not only by dispersal ability but also by host tree identity, the decay stage and local abiotic conditions. However, experiments simultaneously manipulating these potential community drivers in deadwood are lacking. To disentangle the importance of spatial distance and microclimate, as well as host identity and decay stage as drivers of local assemblages, we conducted two consecutive experiments, a 2‐tree species and 6‐tree species experiment with 80 and 72 tree logs, respectively, located in canopy openings and under closed canopies of a montane and a lowland forest. We sampled saproxylic beetles, spiders, fungi and bacterial assemblages from logs. Variation partitioning for community metrics based on a unified framework of Hill numbers showed consistent results for both studies: host identity was most important for sporocarp‐detected fungal assemblages, decay stage and host tree for DNA‐detected fungal assemblages, microclimate and decay stage for beetles and spiders and decay stage for bacteria. Spatial distance was of minor importance for most taxa but showed the strongest effects for arthropods. The contrasting patterns among the taxa highlight the need for multi‐taxon analyses in identifying the importance of abiotic and biotic drivers of community composition. Moreover, the consistent finding of microclimate as the primary driver for saproxylic beetles compared to host identity shows, for the first time that existing evolutionary host adaptions can be outcompeted by local climate conditions in deadwood. KW - deadwood experiments KW - dispersal KW - forest management KW - habitat filter KW - wood-inhabiting fungi Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228201 VL - 129 IS - 10 SP - 1579 EP - 1588 ER - TY - JOUR A1 - Schäbler, Stefan A1 - Amatobi, Kelechi M. A1 - Horn, Melanie A1 - Rieger, Dirk A1 - Helfrich‑Förster, Charlotte A1 - Mueller, Martin J. A1 - Wegener, Christian A1 - Fekete, Agnes T1 - Loss of function in the Drosophila clock gene period results in altered intermediary lipid metabolism and increased susceptibility to starvation JF - Cellular and Molecular Life Sciences N2 - The fruit fly Drosophila is a prime model in circadian research, but still little is known about its circadian regulation of metabolism. Daily rhythmicity in levels of several metabolites has been found, but knowledge about hydrophobic metabolites is limited. We here compared metabolite levels including lipids between period\(^{01}\) (per\(^{01}\)) clock mutants and Canton-S wildtype (WT\(_{CS}\)) flies in an isogenic and non-isogenic background using LC–MS. In the non-isogenic background, metabo-lites with differing levels comprised essential amino acids, kynurenines, pterinates, glycero(phospho)lipids, and fatty acid esters. Notably, detectable diacylglycerols (DAG) and acylcarnitines (AC), involved in lipid metabolism, showed lower levels in per\(^{01}\) mutants. Most of these differences disappeared in the isogenic background, yet the level differences for AC as well as DAG were consistent for fly bodies. AC levels were dependent on the time of day in WTCS in phase with food consumption under LD conditions, while DAGs showed weak daily oscillations. Two short-chain ACs continued to cycle even in constant darkness. per\(^{01}\) mutants in LD showed no or very weak diel AC oscillations out of phase with feeding activity. The low levels of DAGs and ACs in per\(^{01}\) did not correlate with lower total food consumption, body mass or weight. Clock mutant flies showed higher sensitivity to starvation independent of their background-dependent activity level. Our results suggest that neither feeding, energy storage nor mobilisation is significantly affected in per\(^{01}\) mutants, but point towards impaired mitochondrial activity, supported by upregulation of the mitochondrial stress marker 4EBP in the clock mutants KW - circadian rhythms KW - metabolomics KW - mitochondrial activity KW - tryptophan KW - acylcarnitine KW - feeding Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232432 SN - 1420-682X VL - 77 ER - TY - JOUR A1 - Trinkl, Moritz A1 - Kaluza, Benjamin F. A1 - Wallace, Helen A1 - Heard, Tim A. A1 - Keller, Alexander A1 - Leonhardt, Sara D. T1 - Floral Species Richness Correlates with Changes in the Nutritional Quality of Larval Diets in a Stingless Bee JF - Insects N2 - Bees need food of appropriate nutritional quality to maintain their metabolic functions. They largely obtain all required nutrients from floral resources, i.e., pollen and nectar. However, the diversity, composition and nutritional quality of floral resources varies with the surrounding environment and can be strongly altered in human-impacted habitats. We investigated whether differences in plant species richness as found in the surrounding environment correlated with variation in the floral diversity and nutritional quality of larval provisions (i.e., mixtures of pollen, nectar and salivary secretions) composed by the mass-provisioning stingless bee Tetragonula carbonaria (Apidae: Meliponini). We found that the floral diversity of larval provisions increased with increasing plant species richness. The sucrose and fat (total fatty acid) content and the proportion and concentration of the omega-6 fatty acid linoleic acid decreased, whereas the proportion of the omega-3 fatty acid linolenic acid increased with increasing plant species richness. Protein (total amino acid) content and amino acid composition did not change. The protein to fat (P:F) ratio, known to affect bee foraging, increased on average by more than 40% from plantations to forests and gardens, while the omega-6:3 ratio, known to negatively affect cognitive performance, decreased with increasing plant species richness. Our results suggest that plant species richness may support T. carbonaria colonies by providing not only a continuous resource supply (as shown in a previous study), but also floral resources of high nutritional quality. KW - floral resources KW - plant-insect interactions KW - nutrition KW - biodiversity KW - bee decline Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200605 SN - 2075-4450 VL - 11 IS - 2 ER - TY - JOUR A1 - Stelzner, Kathrin A1 - Winkler, Ann-Cathrin A1 - Liang, Chunguang A1 - Boyny, Aziza A1 - Ade, Carsten P. A1 - Dandekar, Thomas A1 - Fraunholz, Martin J. A1 - Rudel, Thomas T1 - Intracellular Staphylococcus aureus Perturbs the Host Cell Ca\(^{2+}\) Homeostasis To Promote Cell Death JF - mBio N2 - The opportunistic human pathogen Staphylococcus aureus causes serious infectious diseases that range from superficial skin and soft tissue infections to necrotizing pneumonia and sepsis. While classically regarded as an extracellular pathogen, S. aureus is able to invade and survive within human cells. Host cell exit is associated with cell death, tissue destruction, and the spread of infection. The exact molecular mechanism employed by S. aureus to escape the host cell is still unclear. In this study, we performed a genome-wide small hairpin RNA (shRNA) screen and identified the calcium signaling pathway as being involved in intracellular infection. S. aureus induced a massive cytosolic Ca\(^{2+}\) increase in epithelial host cells after invasion and intracellular replication of the pathogen. This was paralleled by a decrease in endoplasmic reticulum Ca\(^{2+}\) concentration. Additionally, calcium ions from the extracellular space contributed to the cytosolic Ca2+ increase. As a consequence, we observed that the cytoplasmic Ca\(^{2+}\) rise led to an increase in mitochondrial Ca\(^{2+}\) concentration, the activation of calpains and caspases, and eventually to cell lysis of S. aureus-infected cells. Our study therefore suggests that intracellular S. aureus disturbs the host cell Ca\(^{2+}\) homeostasis and induces cytoplasmic Ca\(^{2+}\) overload, which results in both apoptotic and necrotic cell death in parallel or succession. IMPORTANCE Despite being regarded as an extracellular bacterium, the pathogen Staphylococcus aureus can invade and survive within human cells. The intracellular niche is considered a hideout from the host immune system and antibiotic treatment and allows bacterial proliferation. Subsequently, the intracellular bacterium induces host cell death, which may facilitate the spread of infection and tissue destruction. So far, host cell factors exploited by intracellular S. aureus to promote cell death are only poorly characterized. We performed a genome-wide screen and found the calcium signaling pathway to play a role in S. aureus invasion and cytotoxicity. The intracellular bacterium induces a cytoplasmic and mitochondrial Ca\(^{2+}\) overload, which results in host cell death. Thus, this study first showed how an intracellular bacterium perturbs the host cell Ca\(^{2+}\) homeostasis." KW - Staphylococcus aureus KW - calcium signaling pathway KW - cell death KW - facultatively intracellular pathogens Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231448 VL - 11 ER - TY - JOUR A1 - Sarukhanyan, Edita A1 - Shityakov, Sergey A1 - Dandekar, Thomas T1 - Rational drug design of Axl tyrosine kinase type I inhibitors as promising candidates against cancer JF - Frontiers in Chemistry N2 - The high level of Axl tyrosine kinase expression in various cancer cell lines makes it an attractive target for the development of anti-cancer drugs. In this study, we carried out several sets of in silico screening for the ATP-competitive Axl kinase inhibitors based on different molecular docking protocols. The best drug-like candidates were identified, after parental structure modifications, by their highest affinity to the target protein. We found that our newly designed compound R5, a derivative of the R428 patented analog, is the most promising inhibitor of the Axl kinase according to the three molecular docking algorithms applied in the study. The molecular docking results are in agreement with the molecular dynamics simulations using the MM-PBSA/GBSA implicit solvation models, which confirm the high affinity of R5 toward the protein receptor. Additionally, the selectivity test against other kinases also reveals a high affinity of R5 toward ABL1 and Tyro3 kinases, emphasizing its promising potential for the treatment of malignant tumors. KW - Axl tyrosine kinase KW - anti-cancer drug-like molecules KW - rational drug design KW - molecular docking KW - molecular dynamics Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199505 SN - 2296-2646 VL - 7 IS - 920 ER - TY - JOUR A1 - Römer, Daniela A1 - Cosarinsky, Marcela I. A1 - Roces, Flavio T1 - Selection and spatial arrangement of building materials during the construction of nest turrets by grass-cutting ants JF - Royal Society Open Science N2 - Ants build complex nest structures by reacting to simple, local stimuli. While underground nests result from the space generated by digging, some leaf- and grass-cutting ants also construct conspicuous aboveground turrets around nest openings. We investigated whether the selection of specific building materials occurs during turret construction in Acromyrmex fracticornis grass-cutting ants, and asked whether single building decisions at the beginning can modify the final turret architecture. To quantify workers' material selection, the original nest turret was removed and a choice between two artificial building materials, thin and thick sticks, was offered for rebuilding. Workers preferred thick sticks at the very beginning of turret construction, showed varying preferences thereafter, and changed to prefer thin sticks for the upper, final part of the turret, indicating that they selected different building materials over time to create a stable structure. The impact of a single building choice on turret architecture was evaluated by placing artificial beams that divided a colony's nest entrance at the beginning of turret rebuilding. Splitting the nest entrance led to the self-organized construction of turrets with branched galleries ending in multiple openings, showing that the spatial location of a single building material can strongly influence turret morphology. KW - collective building KW - behavioural plasticity KW - Acromyrmex fracticornis KW - quantitative stigmergy KW - self-organization KW - leaf-cutting ants Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230458 VL - 7 ER - TY - JOUR A1 - Markert, Sebastian M. A1 - Skoruppa, Michael A1 - Yu, Bin A1 - Mulcahy, Ben A1 - Zhen, Mai A1 - Gao, Shangbang A1 - Sendtner, Michael A1 - Stigloher, Christian T1 - Overexpression of an ALS-associated FUS mutation in C. elegans disrupts NMJ morphology and leads to defective neuromuscular transmission JF - Biology Open N2 - The amyotrophic lateral sclerosis (ALS) neurodegenerative disorder has been associated with multiple genetic lesions, including mutations in the gene for fused in sarcoma (FUS), a nuclear-localized RNA/DNA-binding protein. Neuronal expression of the pathological form of FUS proteins in Caenorhabditis elegans results in mislocalization and aggregation of FUS in the cytoplasm, and leads to impairment of motility. However, the mechanisms by which the mutant FUS disrupts neuronal health and function remain unclear. Here we investigated the impact of ALS-associated FUS on motor neuron health using correlative light and electron microscopy, electron tomography, and electrophysiology. We show that ectopic expression of wild-type or ALS-associated human FUS impairs synaptic vesicle docking at neuromuscular junctions. ALS-associated FUS led to the emergence of a population of large, electron-dense, and filament-filled endosomes. Electrophysiological recording revealed reduced transmission from motor neurons to muscles. Together, these results suggest a pathological effect of ALS-causing FUS at synaptic structure and function organization. KW - C. elegans KW - fused in sarcoma KW - amyotrophic lateral sclerosis KW - uper-resolution array tomography KW - electron tomography KW - neuromuscular junction Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230662 VL - 9 ER - TY - JOUR A1 - Rösing, Nils A1 - Salvador, Ellaine A1 - Güntzel, Paul A1 - Kempe, Christoph A1 - Burek, Malgorzata A1 - Holzgrabe, Ulrike A1 - Soukhoroukov, Vladimir A1 - Wunder, Christian A1 - Förster, Carola T1 - Neuroprotective Effects of Isosteviol Sodium in Murine Brain Capillary Cerebellar Endothelial Cells (cerebEND) After Hypoxia JF - Frontiers in Cellular Neuroscience N2 - Ischemic stroke is one of the leading causes of death worldwide. It damages neurons and other supporting cellular elements in the brain. However, the impairment is not only confined to the region of assault but the surrounding area as well. Besides, it also brings about damage to the blood-brain barrier (BBB) which in turn leads to microvascular failure and edema. Hence, this necessitates an on-going, continuous search for intervention strategies and effective treatment. Of late, the natural sweetener stevioside proved to exhibit neuroprotective effects and therapeutic benefits against cerebral ischemia-induced injury. Its injectable formulation, isosteviol sodium (STVNA) also demonstrated favorable results. Nonetheless, its effects on the BBB have not yet been investigated to date. As such, this present study was designed to assess the effects of STVNA in our in vitro stroke model of the BBB.The integrity and permeability of the BBB are governed and maintained by tight junction proteins (TJPs) such as claudin-5 and occludin. Our data show increased claudin-5 and occludin expression in oxygen and glucose (OGD)-deprived murine brain capillary cerebellar endothelial cells (cerebEND) after STVNa treatment. Likewise, the upregulation of the transmembrane protein integrin-αv was also observed. Finally, cell volume was reduced with the simultaneous administration of STVNA and OGD in cerebEND cells. In neuropathologies such as stroke, the failure of cell volume control is a major feature leading to loss of cells in the penumbra as well as adverse outcomes. Our initial findings, therefore, point to the neuroprotective effects of STVNA at the BBB in vitro, which warrant further investigation for a possible future clinical intervention. KW - isosteviol sodium KW - hypoxia KW - cerebEND cells KW - blood brain barrier KW - neuroprotection Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215013 SN - 1662-5102 VL - 14 ER - TY - JOUR A1 - Memmel, Simon A1 - Sisario, Dmitri A1 - Zimmermann, Heiko A1 - Sauer, Markus A1 - Sukhorukov, Vladimir L. A1 - Djuzenova, Cholpon S. A1 - Flentje, Michael T1 - FocAn: automated 3D analysis of DNA repair foci in image stacks acquired by confocal fluorescence microscopy JF - BMC Bioinformatics N2 - Background Phosphorylated histone H2AX, also known as gamma H2AX, forms mu m-sized nuclear foci at the sites of DNA double-strand breaks (DSBs) induced by ionizing radiation and other agents. Due to their specificity and sensitivity, gamma H2AX immunoassays have become the gold standard for studying DSB induction and repair. One of these assays relies on the immunofluorescent staining of gamma H2AX followed by microscopic imaging and foci counting. During the last years, semi- and fully automated image analysis, capable of fast detection and quantification of gamma H2AX foci in large datasets of fluorescence images, are gradually replacing the traditional method of manual foci counting. A major drawback of the non-commercial software for foci counting (available so far) is that they are restricted to 2D-image data. In practice, these algorithms are useful for counting the foci located close to the midsection plane of the nucleus, while the out-of-plane foci are neglected. Results To overcome the limitations of 2D foci counting, we present a freely available ImageJ-based plugin (FocAn) for automated 3D analysis of gamma H2AX foci in z-image stacks acquired by confocal fluorescence microscopy. The image-stack processing algorithm implemented in FocAn is capable of automatic 3D recognition of individual cell nuclei and gamma H2AX foci, as well as evaluation of the total foci number per cell nucleus. The FocAn algorithm consists of two parts: nucleus identification and foci detection, each employing specific sequences of auto local thresholding in combination with watershed segmentation techniques. We validated the FocAn algorithm using fluorescence-labeled gamma H2AX in two glioblastoma cell lines, irradiated with 2 Gy and given up to 24 h post-irradiation for repair. We found that the data obtained with FocAn agreed well with those obtained with an already available software (FoCo) and manual counting. Moreover, FocAn was capable of identifying overlapping foci in 3D space, which ensured accurate foci counting even at high DSB density of up to similar to 200 DSB/nucleus. Conclusions FocAn is freely available an open-source 3D foci analyzer. The user-friendly algorithm FocAn requires little supervision and can automatically count the amount of DNA-DSBs, i.e. fluorescence-labeled gamma H2AX foci, in 3D image stacks acquired by laser-scanning microscopes without additional nuclei staining. KW - DNA double-strand breaks KW - ImageJ plugin KW - gamma H2AX-foci KW - Automated analysis KW - Ionizing radiation KW - Open-source tool KW - Radiation biology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229023 VL - 21 ER - TY - JOUR A1 - Requier, Fabrice A1 - Jowanowitsch, Kim K. A1 - Kallnik, Katharina A1 - Steffan‐Dewenter, Ingolf T1 - Limitation of complementary resources affects colony growth, foraging behavior, and reproduction in bumble bees JF - Ecology N2 - Resource availability in agricultural landscapes has been disturbed for many organisms, including pollinator species. Abundance and diversity in flower availability benefit bee populations; however, little is known about which of protein or carbohydrate resources may limit their growth and reproductive performance. Here, we test the hypothesis of complementary resource limitation using a supplemental feeding approach. We applied this assumption with bumble bees (Bombus terrestris), assuming that colony growth and reproductive performance should depend on the continuous supply of carbohydrates and proteins, through the foraging for nectar and pollen, respectively. We placed wild‐caught bumble bee colonies along a landscape gradient of seminatural habitats, and monitored the colonies’ weight, foraging activity, and reproductive performance during the whole colony cycle. We performed supplemental feeding as an indicator of landscape resource limitation, using a factorial design consisting of the addition of sugar water (carbohydrate, supplemented or not) crossed by pollen (protein, supplemented or not). Bumble bee colony dynamics showed a clear seasonal pattern with a period of growth followed by a period of stagnation. Higher abundance of seminatural habitats resulted in reducing the proportion of pollen foragers relative to all foragers in both periods, and in improving the reproductive performance of bumble bees. Interestingly, the supplemental feeding of sugar water positively affected the colony weight during the stagnation period, and the supplemental feeding of pollen mitigated the landscape effect on pollen collection investment. Single and combined supplementation of sugar water and pollen increased the positive effect of seminatural habitats on reproductive performance. This study reveals a potential colimitation in pollen and nectar resources affecting foraging behavior and reproductive performance in bumble bees, and indicates that even in mixed agricultural landscapes with higher proportions of seminatural habitats, bumble bee populations face resource limitations. We conclude that the seasonal management of floral resources must be considered in conservation to support bumble bee populations and pollination services in farmlands. KW - bombus terrestris KW - seasonal phenology KW - reproductive performance KW - pollen and nectar resources KW - landscape structure KW - feeding experiment Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211891 VL - 101 IS - 3 ER -