TY - JOUR A1 - Brehm, Klaus A1 - Haas, Albert A1 - Goebel, Werner A1 - Kreft, Jürgen T1 - A gene encoding a superoxide dismutase of the facultative intracellular bacterium Listeria monocytogenes N2 - A gene (Imsod) encoding superoxide dismutase (SOD; EC 1.15.1.1) of the facultative intracellular pathogen, Listeria monocytogenes, was cloned by functional complementation of an SOD-deficient Escherichia coli mutant. The nucleotide sequence was determined and the deduced amino acid (aa) sequence (202 aa) showed close similarity to manganese-containing SOD's from other organisms. Subunits of the recombinant L. monocytogenes SOD (re-SOD) and of both E. coli SODs formed enzymatically active hybrid enzymes in vivo. DNA/DNA-hybridization experiments showed that this type of recombinant re-sod gene is conserved within the genus Listeria. KW - Biologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60515 ER - TY - JOUR A1 - Degenkolbe, Elisa A1 - König, Jana A1 - Zimmer, Julia A1 - Walther, Maria A1 - Reißner, Carsten A1 - Nickel, Joachim A1 - Plöger, Frank A1 - Raspopovic, Jelena A1 - Sharpe, James A1 - Dathe, Katharina A1 - Hecht, Jacqueline T. A1 - Mundlos, Stefan A1 - Doelken, Sandra C. A1 - Seemann, Petra T1 - A GDF5 Point Mutation Strikes Twice - Causing BDA1 and SYNS2 JF - PLOS Genetics N2 - Growth and Differentiation Factor 5 (GDF5) is a secreted growth factor that belongs to the Bone Morphogenetic Protein (BMP) family and plays a pivotal role during limb development. GDF5 is a susceptibility gene for osteoarthritis (OA) and mutations in GDF5 are associated with a wide variety of skeletal malformations ranging from complex syndromes such as acromesomelic chondrodysplasias to isolated forms of brachydactylies or multiple synostoses syndrome 2 (SYNS2). Here, we report on a family with an autosomal dominant inherited combination of SYNS2 and additional brachydactyly type A1 (BDA1) caused by a single point mutation in GDF5 (p.W414R). Functional studies, including chondrogenesis assays with primary mesenchymal cells, luciferase reporter gene assays and Surface Plasmon Resonance analysis, of the GDF5 W-414R variant in comparison to other GDF5 mutations associated with isolated BDA1 (p.R399C) or SYNS2 (p.E491K) revealed a dual pathomechanism characterized by a gain-and loss-of-function at the same time. On the one hand insensitivity to the main GDF5 antagonist NOGGIN (NOG) leads to a GDF5 gain of function and subsequent SYNS2 phenotype. Whereas on the other hand, a reduced signaling activity, specifically via the BMP receptor type IA (BMPR1A), is likely responsible for the BDA1 phenotype. These results demonstrate that one mutation in the overlapping interface of antagonist and receptor binding site in GDF5 can lead to a GDF5 variant with pathophysiological relevance for both, BDA1 and SYNS2 development. Consequently, our study assembles another part of the molecular puzzle of how loss and gain of function mutations in GDF5 affect bone development in hands and feet resulting in specific types of brachydactyly and SYNS2. These novel insights into the biology of GDF5 might also provide further clues on the pathophysiology of OA. KW - dominant-negative mutatio KW - morphogenetic protein receptors KW - brachtydacyly type A2 KW - BMP KW - gene encoding noggin KW - growth factor beta KW - signal tranduction KW - molecular mechanism KW - crystal-structure KW - differentiation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127556 SN - 1553-7404 VL - 9 IS - 10 ER - TY - JOUR A1 - Adolfi, Mateus C. A1 - Du, Kang A1 - Kneitz, Susanne A1 - Cabau, Cédric A1 - Zahm, Margot A1 - Klopp, Christophe A1 - Feron, Romain A1 - Paixão, Rômulo V. A1 - Varela, Eduardo S. A1 - de Almeida, Fernanda L. A1 - de Oliveira, Marcos A. A1 - Nóbrega, Rafael H. A1 - Lopez-Roques, Céline A1 - Iampietro, Carole A1 - Lluch, Jérôme A1 - Kloas, Werner A1 - Wuertz, Sven A1 - Schaefer, Fabian A1 - Stöck, Matthias A1 - Guiguen, Yann A1 - Schartl, Manfred T1 - A duplicated copy of id2b is an unusual sex-determining candidate gene on the Y chromosome of arapaima (Arapaima gigas) JF - Scientific Reports N2 - Arapaima gigas is one of the largest freshwater fish species of high ecological and economic importance. Overfishing and habitat destruction are severe threats to the remaining wild populations. By incorporating a chromosomal Hi-C contact map, we improved the arapaima genome assembly to chromosome-level, revealing an unexpected high degree of chromosome rearrangements during evolution of the bonytongues (Osteoglossiformes). Combining this new assembly with pool-sequencing of male and female genomes, we identified id2bbY, a duplicated copy of the inhibitor of DNA binding 2b (id2b) gene on the Y chromosome as candidate male sex-determining gene. A PCR-test for id2bbY was developed, demonstrating that this gene is a reliable male-specific marker for genotyping. Expression analyses showed that this gene is expressed in juvenile male gonads. Its paralog, id2ba, exhibits a male-biased expression in immature gonads. Transcriptome analyses and protein structure predictions confirm id2bbY as a prime candidate for the master sex-determiner. Acting through the TGF beta signaling pathway, id2bbY from arapaima would provide the first evidence for a link of this family of transcriptional regulators to sex determination. Our study broadens our current understanding about the evolution of sex determination genetic networks and provide a tool for improving arapaima aquaculture for commercial and conservation purposes. KW - evolutionary genetics KW - genetic markers KW - genome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265672 VL - 11 IS - 1 ER - TY - THES A1 - Hackl, Thomas T1 - A draft genome for the Venus flytrap, Dionaea muscipula : Evaluation of assembly strategies for a complex Genome – Development of novel approaches and bioinformatics solutions T1 - Ein Genom für die Venus Fliegenfalle, Dionaea muscipula N2 - The Venus flytrap, \textit{Dionaea muscipula}, with its carnivorous life-style and its highly specialized snap-traps has fascinated biologist since the days of Charles Darwin. The goal of the \textit{D. muscipula} genome project is to gain comprehensive insights into the genomic landscape of this remarkable plant. The genome of the diploid Venus flytrap with an estimated size between 2.6 Gbp to 3.0 Gbp is comparatively large and comprises more than 70 % of repetitive regions. Sequencing and assembly of genomes of this scale are even with state-of-the-art technology and software challenging. Initial sequencing and assembly of the genome was performed by the BGI (Beijing Genomics Institute) in 2011 resulting in a 3.7 Gbp draft assembly. I started my work with thorough assessment of the delivered assembly and data. My analysis showed that the BGI assembly is highly fragmented and at the same time artificially inflated due to overassembly of repetitive sequences. Furthermore, it only comprises about on third of the expected genes in full-length, rendering it inadequate for downstream analysis. In the following I sought to optimize the sequencing and assembly strategy to obtain an assembly of higher completeness and contiguity by improving data quality and assembly procedure and by developing tailored bioinformatics tools. Issues with technical biases and high levels of heterogeneity in the original data set were solved by sequencing additional short read libraries from high quality non-polymorphic DNA samples. To address contiguity and heterozygosity I examined numerous alternative assembly software packages and strategies and eventually identified ALLPATHS-LG as the most suited program for assembling the data at hand. Moreover, by utilizing digital normalization to reduce repetitive reads, I was able to substantially reduce computational demands while at the same time significantly increasing contiguity of the assembly. To improve repeat resolution and scaffolding, I started to explore the novel PacBio long read sequencing technology. Raw PacBio reads exhibit high error rates of 15 % impeding their use for assembly. To overcome this issue, I developed the PacBio hybrid correction pipeline proovread (Hackl et al., 2014). proovread uses high coverage Illumina read data in an iterative mapping-based consensus procedure to identify and remove errors present in raw PacBio reads. In terms of sensitivity and accuracy, proovread outperforms existing software. In contrast to other correction programs, which are incapable of handling data sets of the size of D. muscipula project, proovread’s flexible design allows for the efficient distribution of work load on high-performance computing clusters, thus enabling the correction of the Venus flytrap PacBio data set. Next to the assembly process itself, also the assessment of the large de novo draft assemblies, particularly with respect to coverage by available sequencing data, is difficult. While typical evaluation procedures rely on computationally extensive mapping approaches, I developed and implemented a set of tools that utilize k-mer coverage and derived values to efficiently compute coverage landscapes of large-scale assemblies and in addition allow for automated visualization of the of the obtained information in comprehensive plots. Using the developed tools to analyze preliminary assemblies and by combining my findings regarding optimizations of the assembly process, I was ultimately able to generate a high quality draft assembly for D. muscipula. I further refined the assembly by removal of redundant contigs resulting from separate assembly of heterozygous regions and additional scaffolding and gapclosing using corrected PacBio data. The final draft assembly comprises 86 × 10 3 scaffolds and has a total size of 1.45 Gbp. The difference to the estimated genomes size is well explained by collapsed repeats. At the same time, the assembly exhibits high fractions full-length gene models, corroborating the interpretation that the obtained draft assembly provides a complete and comprehensive reference for further exploration of the fascinating biology of the Venus flytrap. N2 - Die Venus Fliegenfalle, D. muscipula fasziniert aufgrund ihres karnivoren Lebensstil und ihrer hochspezialisierten Fallen Biologen schon seit der Zeit von Charles Darwins. Das Ziel des D. muscipula Genomprojekts ist es, neue Einblicke in den genomischen Grundlagen dieser besonderen Pflanze zu gewinnen. Die diploide Venus Fliegenfalle verfügt mit eine geschätzten Größe von 2.6 bp bis 3Gbp über ein vergleichsweise großes Genom, das zudem zu über 70% aus repetitiven Regionen besteht. Sequenzierung und Assembly von Genomen dieser Größenordnung stellen selbst mit neusten technischen und informatischen Methoden eine große Herausforderung dar. Zum ersten mal sequenziert und assembliert wurde das Genom 2011 durch das BGI (Beijing Genomics Institute). Meine Arbeit am Genom der Fliegenfalle begann mit der Analyse des 3.7Gbp großen Assemblies, welches wir vom BGI erhalten haben. Mit meinen Untersuchungen könnte ich zeigen, dass das Assembly stark fragmentiert und gleichzeitig durch überrepräsentierte repetitive Sequenzen stark aufgebläht ist. Darüberhinaus beinhaltet es gerade ein mal eine drittel der erwarteten Gene in Volllänge, wodurch es für die weiter Analyse ungeeignet ist. In meiner weiteren Arbeit habe ich mich daher darauf konzentriert, unsere Sequenzierungsund Assemblierungsstrategie zu verfeinern um ein stärker zusammenhängendes und vollständigeres Assembly zu erhalten. Dafür war es notwendig die Qualität der Sequenzierdaten so wie den Assemblierungsprozess selbst zu optimieren, und Programme zu entwickeln, die eine Verbesserung der Daten und eine Analyse der Zwischenergebnisse ermöglichen. So wurden etwa zur neue Bibliotheken von nicht-polymorphen DNA-Proben sequenziert um die Heterogenität im Datensatz zu verringern. Um die Kontinuität der Assemblies zu verbessern und Probleme mit der Heterozygosität der Daten zu lösen habe ich eine Reihe verschiedener Assemblierungsprogramme getestet. Dabei zeigte sich, dass das Programm ALLPATHS-LG am besten geeignet ist für die Assemblierung von D. muscipula Daten. Durch den Einsatz von digitaler Normalisierung konnte ich den Bedarf an Computerressourcen für einzelne Assemblierungen deutlich reduzieren und gleichzeitig die Kontinuität der Assemblies deutlich erhöhen. Zur besseren Auflösung repetitiver Strukturen im Genom, habe ich auf eine neu entwickelte Sequenziertechnologie von PacBio zurückgegriffen, die deutlich länger Sequenzen erzeugt. Um die neuen Daten trotz ihrer hohen Fehlerrate von 15% für Assemblierungen nutzen zu können, entwickelte ich das Korrekturprogramm proovread (Hackl et al., 2014). proovread nutzt kurze Illumina Sequenzen mit hoher Sequenziertiefe um innerhalb eines iterativen Prozess Fehler in PacBio Daten ausfindig zu machen und zu korrigieren. Das Programm erreicht dabei eine bessere Genauigkeit und eine höhere Sensitivität als vergleichbare Software. Darüber hinaus erlaubt sein flexibles Design auch Datensätze in der Größenordung des Fliegenfallengenoms effizient auf großen Rechenclustern zu bearbeiten. Neben dem Assemblierungsprozess an sich, stellt auch die Analyse von Assemblies großer Genome eine Herausforderung dar. Klassische Methoden basieren oft auf der rechenintensiven Berechnung von Alignments zwischen Sequenzierdaten und Assembly. Um vergleichbare Analysen deutlich schneller generieren zu können, habe ich Programme entwickelt die auf der Auswertung von k-mer Häufigkeiten beruhen, und die gewonnenen Ergebnisse in übersichtlichen Graphiken darstellen. Durch Kombination der so gewonnenen Einblicke und der verschiedenen Erkenntnisse bezüglich der Optimierung es Assemblierungsprozesses, war es mir am Ende möglich, ein Assembly von hoher Qualität für das Genom der Venus Fliegenfalle zu rekonstruieren. Dieses habe ich weiter verfeinert, unter anderem durch das Entfernen heterozygoter Sequenzen und durch das Flicken von Lücken mit Hilfe von PacBio Daten. Das so erstelle Assembly besteht aus 86 × 103 Sequenzen und hat eine Gesamtgröße von 1.45Gbp. Der Unterschied zur erwarteten Genomgröße lässt sich dabei gut durch kollabierte repetitive Regionen erklären. Gleichzeitig untermauert ein hoher Anteil an Volllängengenen im Assembly die Interpretation, dass das vorliegende Assembly eine vollständiges und umfassendes Abbild der D. muscipula Genom zeigt, und dass es sich damit als gute Grundlage für weitere Untersuchungen zur Biologie dieser faszinierenden Pflanze eignet. KW - Venusfliegenfalle KW - genome assembly KW - repeats KW - heterozygosity KW - pacbio correction KW - Genom Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133149 ER - TY - JOUR A1 - Eisenhuth, Nicole A1 - Vellmer, Tim A1 - Rauh, Elisa T. A1 - Butter, Falk A1 - Janzen, Christian J. T1 - A DOT1B/Ribonuclease H2 Protein Complex Is Involved in R-Loop Processing, Genomic Integrity, and Antigenic Variation in Trypanosoma brucei JF - mbio N2 - The parasite Trypanosoma brucei periodically changes the expression of protective variant surface glycoproteins (VSGs) to evade its host's immune sys-tem in a process known as antigenic variation. One route to change VSG expres-sion is the transcriptional activation of a previously silent VSG expression site (ES), a subtelomeric region containing the VSG genes. Homologous recombination of a different VSG from a large reservoir into the active ES represents another route. The conserved histone methyltransferase DOT1B is involved in transcriptional silencing of inactive ES and influences ES switching kinetics. The molecular machin-ery that enables DOT1B to execute these regulatory functions remains elusive, however. To better understand DOT1B-mediated regulatory processes, we purified DOT1B-associated proteins using complementary biochemical approaches. We iden-tified several novel DOT1B interactors. One of these was the RNase H2 complex, previously shown to resolve RNA-DNA hybrids, maintain genome integrity, and play a role in antigenic variation. Our study revealed that DOT1B depletion results in an increase in RNA-DNA hybrids, accumulation of DNA damage, and ES switch-ing events. Surprisingly, a similar pattern of VSG deregulation was observed in RNase H2 mutants. We propose that both proteins act together in resolving R-loops to ensure genome integrity and contribute to the tightly regulated process of anti-genic variation. KW - DOT1B KW - R-loop KW - antigenic variation KW - chromatin structure KW - genomic integrity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260698 VL - 12 IS - 6 ER - TY - JOUR A1 - Gessler, Manfred A1 - Thomas, G. H. A1 - Couillin, P. A1 - Junien, C. A1 - McGillivray, B. C. A1 - Hayden, M. A1 - Jaschek, G. A1 - Bruns, G. A. T1 - A deletion map of the WAGR region on chromosome II N2 - The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals. We have utilized 31 DNA probes which map to the WAGR deletion region, together with six reference loci and 13 WAGR-related deletions, to subdivide this area into 16 intervals. Specific intervals have been correlated with phenotypic features, leading to the identification of individual subregions for the aniridia and Wilms tumor loci. Delineation, by specific probes, of multiple intervals above and below the critical region and of five intervals within the overlap area provides a framework map for molecular characterization of WAGR gene loci and of deletion boundary regions. KW - Biochemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59255 ER - TY - JOUR A1 - Wech, Tobias A1 - Ankenbrand, Markus Johannes A1 - Bley, Thorsten Alexander A1 - Heidenreich, Julius Frederik T1 - A data-driven semantic segmentation model for direct cardiac functional analysis based on undersampled radial MR cine series JF - Magnetic Resonance in Medicine N2 - Purpose Image acquisition and subsequent manual analysis of cardiac cine MRI is time-consuming. The purpose of this study was to train and evaluate a 3D artificial neural network for semantic segmentation of radially undersampled cardiac MRI to accelerate both scan time and postprocessing. Methods A database of Cartesian short-axis MR images of the heart (148,500 images, 484 examinations) was assembled from an openly accessible database and radial undersampling was simulated. A 3D U-Net architecture was pretrained for segmentation of undersampled spatiotemporal cine MRI. Transfer learning was then performed using samples from a second database, comprising 108 non-Cartesian radial cine series of the midventricular myocardium to optimize the performance for authentic data. The performance was evaluated for different levels of undersampling by the Dice similarity coefficient (DSC) with respect to reference labels, as well as by deriving ventricular volumes and myocardial masses. Results Without transfer learning, the pretrained model performed moderately on true radial data [maximum number of projections tested, P = 196; DSC = 0.87 (left ventricle), DSC = 0.76 (myocardium), and DSC =0.64 (right ventricle)]. After transfer learning with authentic data, the predictions achieved human level even for high undersampling rates (P = 33, DSC = 0.95, 0.87, and 0.93) without significant difference compared with segmentations derived from fully sampled data. Conclusion A 3D U-Net architecture can be used for semantic segmentation of radially undersampled cine acquisitions, achieving a performance comparable with human experts in fully sampled data. This approach can jointly accelerate time-consuming cine image acquisition and cumbersome manual image analysis. KW - undersampling KW - cardiovascular magnetic resonance (CMR) KW - deep learning KW - radial KW - semantic segmentation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257616 VL - 87 IS - 2 ER - TY - JOUR A1 - Beer, Katharina A1 - Joschinski, Jens A1 - Sastre, Alazne Arrazola A1 - Krauss, Jochen A1 - Helfrich-Förster, Charlotte T1 - A damping circadian clock drives weak oscillations in metabolism and locomotor activity of aphids (Acyrthosiphon pisum) JF - Scientific Reports N2 - Timing seasonal events, like reproduction or diapause, is crucial for the survival of many species. Global change causes phenologies worldwide to shift, which requires a mechanistic explanation of seasonal time measurement. Day length (photoperiod) is a reliable indicator of winter arrival, but it remains unclear how exactly species measure day length. A reference for time of day could be provided by a circadian clock, by an hourglass clock, or, as some newer models suggest, by a damped circadian clock. However, damping of clock outputs has so far been rarely observed. To study putative clock outputs of Acyrthosiphon pisum aphids, we raised individual nymphs on coloured artificial diet, and measured rhythms in metabolic activity in light-dark illumination cycles of 16:08 hours (LD) and constant conditions (DD). In addition, we kept individuals in a novel monitoring setup and measured locomotor activity. We found that A. pisum is day-active in LD, potentially with a bimodal distribution. In constant darkness rhythmicity of locomotor behaviour persisted in some individuals, but patterns were mostly complex with several predominant periods. Metabolic activity, on the other hand, damped quickly. A damped circadian clock, potentially driven by multiple oscillator populations, is the most likely explanation of our results. KW - circadian mechanisms KW - behavioural ecology KW - damped circadian clock KW - Acyrthosiphon pisum Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170020 VL - 7 IS - 14906 ER - TY - JOUR A1 - Staiger, Christine A1 - Cadot, Sidney A1 - Kooter, Raul A1 - Dittrich, Marcus A1 - Müller, Tobias A1 - Klau, Gunnar W. A1 - Wessels, Lodewyk F. A. T1 - A Critical Evaluation of Network and Pathway-Based Classifiers for Outcome Prediction in Breast Cancer JF - PLoS One N2 - Recently, several classifiers that combine primary tumor data, like gene expression data, and secondary data sources, such as protein-protein interaction networks, have been proposed for predicting outcome in breast cancer. In these approaches, new composite features are typically constructed by aggregating the expression levels of several genes. The secondary data sources are employed to guide this aggregation. Although many studies claim that these approaches improve classification performance over single genes classifiers, the gain in performance is difficult to assess. This stems mainly from the fact that different breast cancer data sets and validation procedures are employed to assess the performance. Here we address these issues by employing a large cohort of six breast cancer data sets as benchmark set and by performing an unbiased evaluation of the classification accuracies of the different approaches. Contrary to previous claims, we find that composite feature classifiers do not outperform simple single genes classifiers. We investigate the effect of (1) the number of selected features; (2) the specific gene set from which features are selected; (3) the size of the training set and (4) the heterogeneity of the data set on the performance of composite feature and single genes classifiers. Strikingly, we find that randomization of secondary data sources, which destroys all biological information in these sources, does not result in a deterioration in performance of composite feature classifiers. Finally, we show that when a proper correction for gene set size is performed, the stability of single genes sets is similar to the stability of composite feature sets. Based on these results there is currently no reason to prefer prognostic classifiers based on composite features over single genes classifiers for predicting outcome in breast cancer. KW - modules KW - protein-interaction networks KW - expression signature KW - classification KW - set KW - metastasis KW - stability KW - survival KW - database KW - markers Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131323 VL - 7 IS - 4 ER - TY - JOUR A1 - Sander, Bodo A1 - Xu, Wenshan A1 - Eilers, Martin A1 - Popov, Nikita A1 - Lorenz, Sonja T1 - A conformational switch regulates the ubiquitin ligase HUWE1 JF - eLife N2 - The human ubiquitin ligase HUWE1 has key roles in tumorigenesis, yet it is unkown how its activity is regulated. We present the crystal structure of a C-terminal part of HUWE1, including the catalytic domain, and reveal an asymmetric auto-inhibited dimer. We show that HUWE1 dimerizes in solution and self-associates in cells, and that both occurs through the crystallographic dimer interface. We demonstrate that HUWE1 is inhibited in cells and that it can be activated by disruption of the dimer interface. We identify a conserved segment in HUWE1 that counteracts dimer formation by associating with the dimerization region intramolecularly. Our studies reveal, intriguingly, that the tumor suppressor p14ARF binds to this segment and may thus shift the conformational equilibrium of HUWE1 toward the inactive state. We propose a model, in which the activity of HUWE1 underlies conformational control in response to physiological cues—a mechanism that may be exploited for cancer therapy. KW - Medicine KW - Structural Biology KW - Molecular Biophysics KW - HUWE1 KW - HECT Ligase KW - Ubiquitin KW - P14ARF KW - X-Ray Chrystallography KW - Enzyme Regulation Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171862 VL - 6 ER - TY - JOUR A1 - Pauls, Dennis A1 - Blechschmidt, Christine A1 - Frantzmann, Felix A1 - el Jundi, Basil A1 - Selcho, Mareike T1 - A comprehensive anatomical map of the peripheral octopaminergic/tyraminergic system of Drosophila melanogaster JF - Scientific Reports N2 - The modulation of an animal’s behavior through external sensory stimuli, previous experience and its internal state is crucial to survive in a constantly changing environment. In most insects, octopamine (OA) and its precursor tyramine (TA) modulate a variety of physiological processes and behaviors by shifting the organism from a relaxed or dormant condition to a responsive, excited and alerted state. Even though OA/TA neurons of the central brain are described on single cell level in Drosophila melanogaster, the periphery was largely omitted from anatomical studies. Given that OA/TA is involved in behaviors like feeding, flying and locomotion, which highly depend on a variety of peripheral organs, it is necessary to study the peripheral connections of these neurons to get a complete picture of the OA/TA circuitry. We here describe the anatomy of this aminergic system in relation to peripheral tissues of the entire fly. OA/TA neurons arborize onto skeletal muscles all over the body and innervate reproductive organs, the heart, the corpora allata, and sensory organs in the antennae, legs, wings and halteres underlining their relevance in modulating complex behaviors. KW - neural circuits KW - peripheral nervous system KW - Drosophila melanogaster Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177412 VL - 8 IS - 15314 ER - TY - JOUR A1 - Jahed, Razieh Rafiei A1 - Kavousi, Mohammad Reza A1 - Farashiani, Mohammad Ebrahim A1 - Sagheb-Talebi, Khosro A1 - Babanezhad, Manoochehr A1 - Courbaud, Benoit A1 - Wirtz, Roland A1 - Müller, Jörg A1 - Larrieu, Laurent T1 - A comparison of the formation rates and composition of tree-related microhabitats in beech-dominated primeval Carpathian and Hyrcanian forests JF - Forests N2 - Primeval forests in the temperate zone exist only as a few remnants, but theses serve as important reference areas for conservation. As key habitats, tree-related microhabitats (TreMs) are of intense interest to forest ecologists, but little is known about their natural composition and dynamics in different tree species. Beech forms a major part of the temperate forests that extend from Europe, home to European beech Fagus sylvatica L. (Fs), eastward to Iran, where Oriental beech Fagus orientalis Lipsky (Fo) is the dominant species. In this study, we compared TreMs in primeval forests of both species, using data from Fo growing in 25 inventory plots throughout the Hyrcanian forest belt in Iran and from Fs growing in a 9 ha permanent plot in the Uholka Forest of Ukraine. TreMs based on 47 types and 11 subgroups were recorded. Beech trees in the Hyrcanian forest had a higher mean diameter at breast height (dbh) than beech trees in Uholka and contained twice as many TreMs per hectare. Although the mean richness of TreMs per TreM bearing tree was similar in the two species, on the basis of the comparison single trees in two groups (n = 405 vs. 2251), the composition of the TreMs clearly differed, as the proportions of rot holes, root-buttress concavities, and crown deadwood were higher in the Hyrcanian Forest, and those of bark losses, exposed heartwood, and burrs and cankers higher in Uholka Forest. Estimates of TreMs dynamics based on dbh and using Weibull models showed a significantly faster cumulative increase of TreMs in Fo, in which saturation occurred already in trees with a dbh of 70–80 cm. By contrast, the increase in TreMs in Fs was continuous. In both species, the probability density was highest at a dbh of about 30 cm, but was twice as high in Fo. Because of limitations of our study design, the reason behind observed differences of TreM formation and composition between regions remains unclear, as it could be either result of the tree species or the environment, or their interaction. However, the observed differences were more likely the result of differences in the environment than in the two tree species. Nevertheless, our findings demonstrate that the Hyrcanian Forest, recently designated as a natural heritage site in Iran, is unique, not only as a tertiary relict or due to its endemic trees, herbs and arthropods, but also because of its TreMs, which form a distinct and rich habitat for associated taxa, including endemic saproxylic species. KW - TreMs KW - Fagus orientalis KW - Fagus sylvatica KW - primeval forest Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200849 SN - 1999-4907 VL - 11 IS - 2 ER - TY - THES A1 - Beer, Katharina T1 - A Comparison of the circadian clock of highly social bees (\(Apis\) \(mellifera\)) and solitary bees (\(Osmia\) \(spec.\)): Circadian clock development, behavioral rhythms and neuroanatomical characterization of two central clock components (PER and PDF) T1 - Ein Vergleich der Inneren Uhr von sozialen Bienen (\(Apis\) \(mellifera\)) und solitären Bienen (\(Osmia\) \(spec.\)): Entwicklung der circadianen Uhr, Verhaltensrhythmen und neuroanatomische Beschreibung von zwei zentralen Uhr Komponenten (PER und PDF) N2 - Summary Bees, like many other organisms, evolved an endogenous circadian clock, which enables them to foresee daily environmental changes and exactly time foraging flights to periods of floral resource availability. The social lifestyle of a honey bee colony has been shown to influence circadian behavior in nurse bees, which do not exhibit rhythmic behavior when they are nursing. On the other hand, forager bees display strong circadian rhythms. Solitary bees, like the mason bee, do not nurse their offspring and do not live in hive communities, but face the same daily environmental changes as honey bees. Besides their lifestyle mason and honey bees differ in their development and life history, because mason bees overwinter after eclosion as adults in their cocoons until they emerge in spring. Honey bees do not undergo diapause and have a relatively short development of a few weeks until they emerge. In my thesis, I present a comparison of the circadian clock of social honey bees (Apis mellifera) and solitary mason bees (Osmia bicornis and Osmia cornuta) on the neuroanatomical level and behavioral output level. I firstly characterized in detail the localization of the circadian clock in the bee brain via the expression pattern of two clock components, namely the clock protein PERIOD (PER) and the neuropeptide Pigment Dispersing Factor (PDF), in the brain of honey bee and mason bee. PER is localized in lateral neuron clusters (which we called lateral neurons 1 and 2: LN1 and LN2) and dorsal neuron clusters (we called dorsal lateral neurons and dorsal neurons: DLN, DN), many glia cells and photoreceptor cells. This expression pattern is similar to the one in other insect species and indicates a common ground plan of clock cells among insects. In the LN2 neuron cluster with cell bodies located in the lateral brain, PER is co-expressed with PDF. These cells build a complex arborization network throughout the brain and provide the perfect structure to convey time information to brain centers, where complex behavior, e.g. sun-compass orientation and time memory, is controlled. The PDF arborizations centralize in a dense network (we named it anterio-lobular PDF hub: ALO) which is located in front of the lobula. In other insects, this fiber center is associated with the medulla (accessory medulla: AME). Few PDF cells build the ALO already in very early larval development and the cell number and complexity of the network grows throughout honey bee development. Thereby, dorsal regions are innervated first by PDF fibers and, in late larval development, the fibers grow laterally to the optic lobe and central brain. The overall expression pattern of PER and PDF are similar in adult social and solitary bees, but I found a few differences in the PDF network density in the posterior protocerebrum and the lamina, which may be associated with evolution of sociality in bees. Secondly, I monitored activity rhythms, for which I developed and established a device to monitor locomotor activity rhythms of individual honey bees with contact to a mini colony in the laboratory. This revealed new aspects of social synchronization and survival of young bees with indirect social contact to the mini colony (no trophalaxis was possible). For mason bees, I established a method to monitor emergence and locomotor activity rhythms and I could show that circadian emergence rhythms are entrainable by daily temperature cycles. Furthermore, I present the first locomotor activity rhythms of solitary bees, which show strong circadian rhythms in their behavior right after emergence. Honey bees needed several days to develop circadian locomotor rhythms in my experiments. I hypothesized that honey bees do not emerge with a fully matured circadian system in the hive, while solitary bees, without the protection of a colony, would need a fully matured circadian clock right away after emergence. Several indices in published work and preliminary studies support my hypothesis and future studies on PDF expression in different developmental stages in solitary bees may provide hard evidence. N2 - Zusammenfassung Bienen, sowie viele andere Organismen, evolvierten eine innere circadiane Uhr, die es ihnen ermöglicht, tägliche Umweltveränderungen voraus zu sehen und ihre Foragierflüge zu Tageszeiten durchzuführen, wenn sie möglichst viele Blüten besuchen können. Es zeigte sich, dass der soziale Lebensstil der Honigbiene Einfluss auf das rhythmische Verhalten der Ammenbienen hat, die während der Brutpflege keinen täglichen Rhythmus im Verhalten aufweisen. Sammlerbienen auf der anderen Seite zeigen ein stark rhythmisches Verhalten. Solitäre Bienen, wie die Mauerbiene, betreiben keine Brutpflege und leben nicht in einer Staatengemeinschaft, aber sind den gleichen Umweltveränderungen ausgesetzt. Nicht nur Lebensstil, sondern auch Entwicklung und Lebenszyklus unterscheiden sich zwischen Honig- und Mauerbienen. Mauerbienen überwintern als adulte Insekten in einem Kokon bis sie im Frühjahr schlüpfen. Honigbienen durchleben keine Diapause und schlüpfen nach wenigen Wochen der Entwicklung im Bienenstock. In meiner Dissertation vergleiche ich die circadiane Uhr von sozialen Honigbienen (Apis mellifera) und solitären Mauerbienen (Osmia bicornis und Osmia cornuta) auf Ebene der Neuroanatomie und das durch die innere Uhr verursachte rhythmische Verhalten. Erstens charakterisierte ich detailliert die Lage der circadianen Uhr im Gehirn von Honig- und Mauerbiene anhand des Expressionsmusters von zwei Uhrkomponenten. Diese sind das Uhrprotein PERIOD (PER) und das Neuropeptid Pigment Dispersing Factor (PDF). PER wird exprimiert in lateralen Neuronen-Gruppen (die wir laterale Neurone 1 und 2 nannten: LN1 und LN2) und dorsalen Neuronen-Gruppen (benannt dorsal laterale Neurone und dorsale Neurone: DLN und DN), sowie in vielen Gliazellen und Fotorezeptorzellen. Dieses Expressionsmuster liegt ähnlich in anderen Insektengruppen vor und deutet auf einen Grundbauplan der Inneren Uhr im Gehirn von Insekten hin. In der LN2 Neuronen-Gruppe, deren Zellkörper im lateralen Gehirn liegen, sind PER und PDF in den gleichen Zellen co-lokalisiert. Diese Zellen bilden ein komplexes Netzwerk aus Verzweigungen durch das gesamte Gehirn und liefern damit die perfekte Infrastruktur, um Zeitinformation an Gehirnregionen weiterzuleiten, die komplexe Verhaltensweisen, wie Sonnenkompass-Orientierung und Zeitgedächtnis, steuern. Alle PDF Neuriten laufen in einer anterior zur Lobula liegenden Region zusammen (sie wurde ALO, anterio-lobular PDF Knotenpunkt, genannt). Dieser Knotenpunkt ist in anderen Insekten mit der Medulla assoziiert und wird akzessorische Medulla (AME) genannt. Wenige PDF Zellen bilden bereits im frühen Larvalstadium diesen ALO und die Zellzahl sowie die Komplexität des Netzwerks wächst die gesamte Entwicklung der Honigbiene hindurch. Dabei werden zuerst die dorsalen Gehirnregionen von PDF Neuronen innerviert und in der späteren Larvalentwicklung wachsen die Neurite lateral in Richtung der optischen Loben und des Zentralgehirns. Das generelle Expressionsmuster von PER und PDF in adulten sozialen und solitären Bienen ähnelt sich stark, aber ich identifizierte kleine Unterschiede in der PDF Netzwerkdichte im posterioren Protocerebrum und in der Lamina. Diese könnten mit der Evolution von sozialen Bienen assoziiert sein. Zweitens entwickelte und etablierte ich eine Methode, Lokomotionsrhythmen von individuellen Bienen im Labor aufzunehmen, die in Kontakt mit einem Miniaturvolk standen. Diese Methode enthüllte neue Aspekte der sozialen Synchronisation unter Honigbienen und des Überlebens von jungen Bienen, die indirekten sozialen Kontakt zu dem Miniaturvolk hatten (Trophalaxis war nicht möglich). Für Mauerbienen etablierte ich eine Methode Schlupf- und lokomotorische Aktivitätsrhythmik aufzuzeichnen und konnte damit zeigen, dass tägliche Rhythmen im Schlupf durch Synchronisation der circadianen Uhr in Mauerbienen durch Tagestemperatur-Zyklen erzielt werden kann. Des Weiteren präsentiere ich die ersten lokomotorischen Aktivitätsrhythmen von solitären Bienen, die sofort nach ihrem Schlupf einen starken circadianen Rhythmus im Verhalten aufwiesen. Honigbienen brauchten in meinen Experimenten mehrere Tage, um circadiane Rhythmen in Lokomotion zu entwickeln. Ich erstellte die Hypothese, dass Honigbienen zum Zeitpunkt des Schlupfes im Bienenvolk ein noch nicht vollständig ausgereiftes circadianes System besitzen, während solitäre Bienen, die ohne den Schutz eines Volkes sind, direkt nach dem Schlupf eine vollständig ausgereifte Uhr brauchen. Mehrere Hinweise in Publikationen und Vorversuchen unterstützen meine Hypothese. Zukünftige Studien der Entwicklung des PDF Neuronen-Netzwerkes in solitären Bienen unterschiedlicher Entwicklungsstufen könnten dies nachweisen. KW - Chronobiologie KW - circadian rhythms KW - honeybee KW - Mauerbiene KW - Neuroanatomie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159765 ER - TY - JOUR A1 - Uhler, Johannes A1 - Haase, Peter A1 - Hoffmann, Lara A1 - Hothorn, Torsten A1 - Schmidl, Jürgen A1 - Stoll, Stefan A1 - Welti, Ellen A. R. A1 - Buse, Jörn A1 - Müller, Jörg T1 - A comparison of different Malaise trap types JF - Insect Conservation and Diversity N2 - Recent reports on insect decline have highlighted the need for long‐term data on insect communities towards identifying their trends and drivers. With the launch of many new insect monitoring schemes to investigate insect communities over large spatial and temporal scales, Malaise traps have become one of the most important tools due to the broad spectrum of species collected and reduced capture bias through passive sampling of insects day and night. However, Malaise traps can vary in size, shape, and colour, and it is unknown how these differences affect biomass, species richness, and composition of trap catch, making it difficult to compare results between studies. We compared five Malaise trap types (three variations of the Townes and two variations of the Bartak Malaise trap) to determine their effects on biomass and species richness as identified by metabarcoding. Insect biomass varied by 20%–55%, not strictly following trap size but varying with trap type. Total species richness was 20%–38% higher in the three Townes trap models compared to the Bartak traps. Bartak traps captured lower richness of highly mobile taxa but increased richness of ground‐dwelling taxa. The white roofed Townes trap captured a higher richness of pollinators. We find that biomass, total richness, and taxa group specific richness are all sensitive to Malaise trap type. Trap type should be carefully considered and aligned to match monitoring and research questions. Additionally, our estimates of trap type effects can be used to adjust results to facilitate comparisons across studies. KW - Bartak KW - biodiversity KW - insect communities KW - insect monitoring KW - Malaise trap KW - Townes KW - trap selectivity Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-293694 VL - 15 IS - 6 SP - 666 EP - 672 ER - TY - JOUR A1 - Duschl, Albert A1 - Jahn, Ute A1 - Bertling, Claudia A1 - Sebald, Walter T1 - A comparison of assays for the response of primary human T-cells upon stimulation with interleukin-2, interleukin-4 and interleukin-7 N2 - The most commonly used assay to quantitate the response of peripheral T~cells upon stimulation with growth factors is determination of incorporated (JH]TdR. We compared thls test to three other methods: 1. direct countlog of cells with a Coulter type counter as reference assay, 2. a colorimetric assay using the tetrazolium dye 3-[ 4,S-dimethylthiazol-l-yl]-2,5diphenyl tetrazolium (MTT), which is a cheap and increasingly popular non-radioactive method and 3. incorporation of the thymidine analog 5-bromo-2'-deoxyuridine detection with a monoclonal antibody on cytospins. Primary human PHA-blasts from >30 healthy individuals were stimulated with IL-2, IL-4 aod IL-7 and assayed with up to four different methods. We discuss the advantages and disadvantages of the assays used and tbe effects of differences between cell preparations. We observed no significant variations between individuals for the dose dependence, but the relative emctency of IL4 compared to IL-2 and IL-7 was variable. This was probably due to the slower response observed upon stimulation with this factor. KW - T-Lymphozyt KW - Interleukin 2 KW - Interleukin 4 KW - Interleukin 7 KW - T-cells KW - proliferation assays KW - IL-2 KW - IL-4 KW - IL-7 Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86750 ER - TY - JOUR A1 - Biscotti, Maria Assunta A1 - Adolfi, Mateus Contar A1 - Barucca, Marco A1 - Forconi, Mariko A1 - Pallavicini, Alberto A1 - Gerdol, Marco A1 - Canapa, Adriana A1 - Schartl, Manfred T1 - A comparative view on sex differentiation and gametogenesis genes in lungfish and coelacanths JF - Genome Biology and Evolution N2 - Gonadal sex differentiation and reproduction are the keys to the perpetuation of favorable gene combinations and positively selected traits. In vertebrates, several gonad development features that differentiate tetrapods and fishes are likely to be, at least in part, related to the water-to-land transition. The collection of information from basal sarcopterygians, coelacanths, and lungfishes, is crucial to improve our understanding of the molecular evolution of pathways involved in reproductive functions, since these organisms are generally regarded as “living fossils” and as the direct ancestors of tetrapods. Here, we report for the first time the characterization of >50 genes related to sex differentiation and gametogenesis in Latimeria menadoensis and Protopterus annectens. Although the expression profiles of most genes is consistent with the intermediate position of basal sarcopterygians between actinopterygian fish and tetrapods, their phylogenetic placement and presence/absence patterns often reveal a closer affinity to the tetrapod orthologs. On the other hand, particular genes, for example, the male gonad factor gsdf (Gonadal Soma-Derived Factor), provide examples of ancestral traits shared with actinopterygians, which disappeared in the tetrapod lineage. KW - sex differentiation KW - Latimeria menadoensis KW - Protopterus annectens KW - evolution KW - testis KW - gametogenesis KW - ovary Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176774 VL - 10 IS - 6 ER - TY - JOUR A1 - Niewalda, Thomas A1 - Völler, Thomas A1 - Eschbach, Claire A1 - Ehmer, Julia A1 - Chou, Wen-Chuang A1 - Timme, Marc A1 - Fiala, André A1 - Gerber, Bertram T1 - A Combined Perceptual, Physico-Chemical, and ImagingApproach to ‘Odour-Distances’ Suggests a CategorizingFunction of the Drosophila Antennal Lobe N2 - How do physico-chemical stimulus features, perception, and physiology relate? Given the multi-layered and parallel architecture of brains, the question specifically is where physiological activity patterns correspond to stimulus features and/ or perception. Perceived distances between six odour pairs are defined behaviourally from four independent odour recognition tasks. We find that, in register with the physico-chemical distances of these odours, perceived distances for 3-octanol and n-amylacetate are consistently smallest in all four tasks, while the other five odour pairs are about equally distinct. Optical imaging in the antennal lobe, using a calcium sensor transgenically expressed in only first-order sensory or only second-order olfactory projection neurons, reveals that 3-octanol and n-amylacetate are distinctly represented in sensory neurons, but appear merged in projection neurons. These results may suggest that within-antennal lobe processing funnels sensory signals into behaviourally meaningful categories, in register with the physico-chemical relatedness of the odours. KW - Drosophila Antennal Lobe Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74769 ER - TY - JOUR A1 - Niewalda, Thomas A1 - Völler, Thomas A1 - Eschbach, Claire A1 - Ehmer, Julia A1 - Wen-Chuang, Chou A1 - Timme, Marc A1 - Fiala, André A1 - Gerber, Bertram T1 - A Combined Perceptual, Physico-Chemical, and Imaging Approach to 'Odour-Distances' Suggests a Categorizing Function of the Drosophila Antennal Lobe JF - PLoS One N2 - How do physico-chemical stimulus features, perception, and physiology relate? Given the multi-layered and parallel architecture of brains, the question specifically is where physiological activity patterns correspond to stimulus features and/or perception. Perceived distances between six odour pairs are defined behaviourally from four independent odour recognition tasks. We find that, in register with the physico-chemical distances of these odours, perceived distances for 3octanol and n-amylacetate are consistently smallest in all four tasks, while the other five odour pairs are about equally distinct. Optical imaging in the antennal lobe, using a calcium sensor transgenically expressed in only first-order sensory or only second-order olfactory projection neurons, reveals that 3-octanol and n-amylacetate are distinctly represented in sensory neurons, but appear merged in projection neurons. These results may suggest that within-antennal lobe processing funnels sensory signals into behaviourally meaningful categories, in register with the physico-chemical relatedness of the odours. KW - organization KW - cameleon KW - honeybee KW - map KW - neurons KW - reveals KW - melanogaster KW - mushroom body KW - spatial representation KW - olfactory information Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133510 VL - 6 IS - 9 ER - TY - JOUR A1 - Schuhmann, Antonia A1 - Scheiner, Ricarda T1 - A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees JF - Ecotoxicology and Environmental Safety N2 - The increasing loss of pollinators over the last decades has become more and more evident. Intensive use of plant protection products is one key factor contributing to this decline. Especially the mixture of different plant protection products can pose an increased risk for pollinators as synergistic effects may occur. In this study we investigated the effect of the fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their mixture on honeybees. Since both plant protection products are frequently applied sequentially to the same plants (e.g. oilseed rape), their combination is a realistic scenario for honeybees. We investigated the mortality, the sucrose responsiveness and the differential olfactory learning performance of honeybees under controlled conditions in the laboratory to reduce environmental noise. Intact sucrose responsiveness and learning performance are of pivotal importance for the survival of individual honeybees as well as for the functioning of the entire colony. Treatment with two sublethal and field relevant concentrations of each plant protection product did not lead to any significant effects on these behaviors but affected the mortality rate. However, our study cannot exclude possible negative sublethal effects of these substances in higher concentrations. In addition, the honeybee seems to be quite robust when it comes to effects of plant protection products, while wild bees might be more sensitive. Highlights • Mix of SBI fungicides and neonicotinoids can lead to synergistic effects for bees. • Combination of non-SBI fungicide and neonicotinoid in field-realistic doses tested. • Synergistic effect on mortality of honeybees. • No effects on sucrose responsiveness and learning performance of honeybees. • Synergistic effects by other pesticide mixtures or on wild bees cannot be excluded. KW - Apis mellifera KW - non-SBI fungicide KW - insecticide KW - pesticide mixture KW - synergistic effect KW - sublethal effect Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350047 VL - 256 ER - TY - JOUR A1 - Drescher, Nora A1 - Klein, Alexandra-Maria A1 - Schmitt, Thomas A1 - Leonhardt, Sara Diana T1 - A clue on bee glue: New insight into the sources and factors driving resin intake in honeybees (Apis mellifera) JF - PLoS ONE N2 - Honeybees (Apis mellifera) are threatened by numerous pathogens and parasites. To prevent infections they apply cooperative behavioral defenses, such as allo-grooming and hygiene, or they use antimicrobial plant resin. Resin is a chemically complex and highly variable mixture of many bioactive compounds. Bees collect the sticky material from different plant species and use it for nest construction and protection. Despite its importance for colony health, comparatively little is known about the precise origins and variability in resin spectra collected by honeybees. To identify the botanical resin sources of A. mellifera in Western Europe we chemically compared resin loads of individual foragers and tree resins. We further examined the resin intake of 25 colonies from five different apiaries to assess the effect of location on variation in the spectra of collected resin. Across all colonies and apiaries, seven distinct resin types were categorized according to their color and chemical composition. Matches between bee-collected resin and tree resin indicated that bees used poplar (Populus balsamifera, P. x canadensis), birch (Betula alba), horse chestnut (Aesculus hippocastanum) and coniferous trees (either Picea abies or Pinus sylvestris) as resin sources. Our data reveal that honeybees collect a comparatively broad and variable spectrum of resin sources, thus assuring protection against a variety of antagonists sensitive to different resins and/or compounds. We further unravel distinct preferences for specific resins and resin chemotypes, indicating that honeybees selectively search for bioactive resin compounds. KW - Honey bees KW - Poplars KW - Trees KW - Forests KW - Chemical composition KW - Bees KW - Conifers KW - Phenols Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200935 VL - 14 IS - 2 ER -