@phdthesis{KuklovskyformerFinke2024, author = {Kuklovsky [former Finke], Valerie}, title = {Are some bees smarter than others? An examination of consistent individual differences in the cognitive abilities of honey bees}, doi = {10.25972/OPUS-32301}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323012}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Cognition refers to the ability to of animals to acquire, process, store and use vital information from the environment. Cognitive processes are necessary to predict the future and reduce the uncertainty of the ever-changing environment. Classically, research on animal cognition focuses on decisive cognitive tests to determine the capacity of a species by the testing the ability of a few individuals. This approach views variability between these tested key individuals as unwanted noise and is thus often neglected. However, inter-individual variability provides important insights to behavioral plasticity, cognitive specialization and brain modularity. Honey bees Apis mellifera are a robust and traditional model for the study of learning, memory and cognition due to their impressive capabilities and rich behavioral repertoire. In this thesis I have applied a novel view on the learning abilities of honey bees by looking explicitly at individual differences in a variety of learning tasks. Are some individual bees consistently smarter than some of her sisters? If so, will a smart individual always perform good independent of the time, the context and the cognitive requirements or do bees show distinct isolated 'cognitive modules'? My thesis presents the first comprehensive investigation of consistent individual differences in the cognitive abilities of honey bees. To speak of an individual as behaving consistently, a crucial step is to test the individual multiple times to examine the repeatability of a behavior. I show that free-flying bees remain consistent in a visual discrimination task for three consecutive days. Successively, I explored individual consistency in cognitive proficiency across tasks involving different sensory modalities, contexts and cognitive requirements. I found that free-flying bees show a cognitive specialization between visual and olfactory learning but remained consistent across a simple discrimination task and a complex concept learning task. I wished to further explore individual consistency with respect to tasks of different cognitive complexity, a question that has never been tackled before in an insect. I thus performed a series of four experiments using either visual or olfactory stimuli and a different training context (free-flying and restrained) and tested bees in a discrimination task, reversal learning and negative patterning. Intriguingly, across all these experiments I evidenced the same results: The bees' performances were consistent across the discrimination task and reversal learning and negative patterning respectively. No association was evidenced between reversal learning and negative patterning. After establishing the existence of consistent individual differences in the cognitive proficiency of honey bees I wished to determine factors which could underlie these differences. Since genetic components are known to underlie inter-individual variability in learning abilities, I studied the effects of genetics on consistency in cognitive proficiency by contrasting bees originating from either from a hive with a single patriline (low genetic diversity) or with multiple patrilines (high genetic diversity). These two groups of bees showed differences in the patterns of individually correlated performances, indicating a genetic component accounts for consistent cognitive individuality. Another major factor underlying variability in learning performances is the individual responsiveness to sucrose solution and to visual stimuli, as evidenced by many studies on restrained bees showing a positive correlation between responsiveness to task relevant stimuli and learning performances. I thus tested whether these relationships between sucrose/visual responsiveness and learning performances are applicable for free-flying bees. Free-flying bees were again subjected to reversal learning and negative patterning and subsequently tested in the laboratory for their responsiveness to sucrose and to light. There was no evidence of a positive relationship between sucrose/visual responsiveness and neither performances of free-flying bees in an elemental discrimination, reversal learning and negative patterning. These findings indicate that relationships established between responsiveness to task relevant stimuli and learning proficiency established in the laboratory with restrained bees might not hold true for a completely different behavioral context i.e. for free-flying bees in their natural environment. These results show that the honey bee is an excellent insect model to study consistency in cognitive proficiency and to identify the underlying factors. I mainly discuss the results with respect to the question of brain modularity in insects and the adaptive significance of individuality in cognitive abilities for honey bee colonies. I also provide a proposition of research questions which tie in this theme of consistent cognitive proficiency and could provide fruitful areas for future research.}, subject = {Lernen}, language = {en} } @article{BecherAndresPonsRomanovetal.2018, author = {Becher, Isabelle and Andr{\´e}s-Pons, Amparo and Romanov, Natalie and Stein, Frank and Schramm, Maike and Baudin, Florence and Helm, Dominic and Kurzawa, Nils and Mateus, Andr{\´e} and Mackmull, Marie-Therese and Typas, Athanasios and M{\"u}ller, Christoph W. and Bork, Peer and Beck, Martin and Savitski, Mikhail M.}, title = {Pervasive Protein Thermal Stability Variation during the Cell Cycle}, series = {Cell}, volume = {173}, journal = {Cell}, doi = {10.1016/j.cell.2018.03.053}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221565}, pages = {1495-1507}, year = {2018}, abstract = {Quantitative mass spectrometry has established proteome-wide regulation of protein abundance and post-translational modifications in various biological processes. Here, we used quantitative mass spectrometry to systematically analyze the thermal stability and solubility of proteins on a proteome-wide scale during the eukaryotic cell cycle. We demonstrate pervasive variation of these biophysical parameters with most changes occurring in mitosis and G1. Various cellular pathways and components vary in thermal stability, such as cell-cycle factors, polymerases, and chromatin remodelers. We demonstrate that protein thermal stability serves as a proxy for enzyme activity, DNA binding, and complex formation in situ. Strikingly, a large cohort of intrinsically disordered and mitotically phosphorylated proteins is stabilized and solubilized in mitosis, suggesting a fundamental remodeling of the biophysical environment of the mitotic cell. Our data represent a rich resource for cell, structural, and systems biologists interested in proteome regulation during biological transitions.}, language = {en} } @article{MooijvanWijkBeusenetal.2019, author = {Mooij, Wolf M and van Wijk, Dianneke and Beusen, Arthur HW and Brederveld, Robert J and Chang, Manqi and Cobben, Marleen MP and DeAngelis, Don L and Downing, Andrea S and Green, Pamela and Gsell, Alena S and Huttunen, Inese and Janse, Jan H and Janssen, Annette BG and Hengeveld, Geerten M and Kong, Xiangzhen and Kramer, Lilith and Kuiper, Jan J and Langan, Simon J and Nolet, Bart A and Nuijten, Rascha JM and Strokal, Maryna and Troost, Tineke A and van Dam, Anne A and Teurlincx, Sven}, title = {Modeling water quality in the Anthropocene: directions for the next-generation aquatic ecosystem models}, series = {Current Opinion in Environmental Sustainability}, volume = {36}, journal = {Current Opinion in Environmental Sustainability}, doi = {10.1016/j.cosust.2018.10.012}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224173}, pages = {85-95}, year = {2019}, abstract = {"Everything changes and nothing stands still" (Heraclitus). Here we review three major improvements to freshwater aquatic ecosystem models — and ecological models in general — as water quality scenario analysis tools towards a sustainable future. To tackle the rapid and deeply connected dynamics characteristic of the Anthropocene, we argue for the inclusion of eco-evolutionary, novel ecosystem and social-ecological dynamics. These dynamics arise from adaptive responses in organisms and ecosystems to global environmental change and act at different integration levels and different time scales. We provide reasons and means to incorporate each improvement into aquatic ecosystem models. Throughout this study we refer to Lake Victoria as a microcosm of the evolving novel social-ecological systems of the Anthropocene. The Lake Victoria case clearly shows how interlinked eco-evolutionary, novel ecosystem and social-ecological dynamics are, and demonstrates the need for transdisciplinary research approaches towards global sustainability.}, language = {en} } @article{FlunkertMaierhoferDittrichetal.2018, author = {Flunkert, Julia and Maierhofer, Anna and Dittrich, Marcus and M{\"u}ller, Tobias and Horvath, Steve and Nanda, Indrajit and Haaf, Thomas}, title = {Genetic and epigenetic changes in clonal descendants of irradiated human fibroblasts}, series = {Experimental Cell Research}, volume = {370}, journal = {Experimental Cell Research}, doi = {10.1016/j.yexcr.2018.06.034}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228177}, pages = {322-332}, year = {2018}, abstract = {To study delayed genetic and epigenetic radiation effects, which may trigger radiation-induced carcinogenesis, we have established single-cell clones from irradiated and non-irradiated primary human fibroblasts. Stable clones were endowed with the same karyotype in all analyzed metaphases after 20 population doublings (PDs), whereas unstable clones displayed mosaics of normal and abnormal karyotypes. To account for variation in radiation sensitivity, all experiments were performed with two different fibroblast strains. After a single X-ray dose of 2 Gy more than half of the irradiated clones exhibited radiation-induced genome instability (RIGI). Irradiated clones displayed an increased rate of loss of chromosome Y (LOY) and copy number variations (CNVs), compared to controls. CNV breakpoints clustered in specific chromosome regions, in particular 3p14.2 and 7q11.21, coinciding with common fragile sites. CNVs affecting the FHIT gene in FRA3B were observed in independent unstable clones and may drive RIGI. Bisulfite pyrosequencing of control clones and the respective primary culture revealed global hypomethylation of ALU, LINE-1, and alpha-satellite repeats as well as rDNA hypermethylation during in vitro ageing. Irradiated clones showed further reduced ALU and alpha-satellite methylation and increased rDNA methylation, compared to controls. Methylation arrays identified several hundred differentially methylated genes and several enriched pathways associated with in vitro ageing. Methylation changes in 259 genes and the MAP kinase signaling pathway were associated with delayed radiation effects (after 20 PDs). Collectively, our results suggest that both genetic (LOY and CNVs) and epigenetic changes occur in the progeny of exposed cells that were not damaged directly by irradiation, likely contributing to radiation-induced carcinogenesis. We did not observe epigenetic differences between stable and unstable irradiated clones. The fact that the DNA methylation (DNAm) age of clones derived from the same primary culture varied greatly suggests that DNAm age of a single cell (represented by a clone) can be quite different from the DNAm age of a tissue. We propose that DNAm age reflects the emergent property of a large number of individual cells whose respective DNAm ages can be highly variable.}, language = {en} } @article{SchubertHagedornYoshiietal.2018, author = {Schubert, Frank K. and Hagedorn, Nicolas and Yoshii, Taishi and Helfrich-F{\"o}rster, Charlotte and Rieger, Dirk}, title = {Neuroanatomical details of the lateral neurons of Drosophila melanogaster support their functional role in the circadian system}, series = {Journal of Comparative Neurology}, volume = {526}, journal = {Journal of Comparative Neurology}, doi = {10.1002/cne.24406}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234477}, pages = {1209-1231}, year = {2018}, abstract = {Drosophila melanogaster is a long-standing model organism in the circadian clock research. A major advantage is the relative small number of about 150 neurons, which built the circadian clock in Drosophila. In our recent work, we focused on the neuroanatomical properties of the lateral neurons of the clock network. By applying the multicolor-labeling technique Flybow we were able to identify the anatomical similarity of the previously described E2 subunit of the evening oscillator of the clock, which is built by the 5th small ventrolateral neuron (5th s-LNv) and one ITP positive dorsolateral neuron (LNd). These two clock neurons share the same spatial and functional properties. We found both neurons innervating the same brain areas with similar pre- and postsynaptic sites in the brain. Here the anatomical findings support their shared function as a main evening oscillator in the clock network like also found in previous studies. A second quite surprising finding addresses the large lateral ventral PDF-neurons (l-LNvs). We could show that the four hardly distinguishable l-LNvs consist of two subgroups with different innervation patterns. While three of the neurons reflect the well-known branching pattern reproduced by PDF immunohistochemistry, one neuron per brain hemisphere has a distinguished innervation profile and is restricted only to the proximal part of the medulla-surface. We named this neuron "extra" l-LNv (l-LNvx). We suggest the anatomical findings reflect different functional properties of the two l-LNv subgroups.}, language = {en} } @phdthesis{Korte2024, author = {Korte, Pamela}, title = {Die funktionelle Bedeutung des Lipidstoffwechsels f{\"u}r die Stomata{\"o}ffnung bei Hitzestress in \(Arabidopsis\) \(thaliana\)}, doi = {10.25972/OPUS-37046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-370461}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Pflanzen sind verschiedenen Umweltbedingungen ausgesetzt, die zu suboptimalen Wachstumsbedingungen f{\"u}hren k{\"o}nnen. Dies gilt f{\"u}r eine Vielzahl von biotischen und abiotischen Faktoren. In der hier vorgelegten Arbeit wird der Effekt von erh{\"o}hten Temperaturen und Hitze genauer analysiert. Hitze ist einer der wichtigsten abiotischen Stressfaktoren, der das Pflanzenwachstum und die Reproduktion beeinflusst. Viele wichtige Kulturpflanzen zeigen immense Ertragseinbußen, die durch Hitze hervorgerufen werden. Durch den fortschreitenden Klimawandel werden jedoch Hitzeperioden immer h{\"a}ufiger und somit die Folgen f{\"u}r die Nahrungsproduktion immer gravierender. Zur Z{\"u}chtung von Pflanzen die hitzetolerant sind und weniger hohe Ertragseinbußen unter diesem Stress aufweisen, ist es essenziell die grundlegenden molekularen Mechanismen der Hitzetoleranz zu verstehen. Es m{\"u}ssen die verschiedenen physiologischen und biochemischen Prozesse identifiziert werden, die es Pflanzen erm{\"o}glichen, sich anzupassen. Es ist bekannt, dass die Anpassungsmechanismen von Pflanzen komplex sind und sowohl Ver{\"a}nderungen auf zellul{\"a}rer wie auch auf organismischer Ebene beinhalten. Ziel dieser Arbeit war es, weitere Erkenntnisse zu gewinnen, wie diese Anpassung vonstattengeht und welche molekularen Prozesse an ihr beteiligt sind. Ein Hauptaugenmerk lag dabei auf dem Einfluss des Lipidmetabolismus und den daran beteiligten Enzymen. Es konnte bereits gezeigt werden, dass die Akkumulation von Triacylglycerolen bei hohen Temperaturen die basale Thermotoleranz bei Arabidopsis thaliana erh{\"o}ht. Wie jedoch der genaue Mechanismus dieser durch Triacylglycerole vermittelten Thermotoleranz funktioniert, war bis dato nicht bekannt. Ich konnte zeigen, dass die angesammelten Triacylglycerole genutzt werden k{\"o}nnen, um die Stomata w{\"a}hrend des Hitzestress zu {\"o}ffnen. Dies f{\"u}hrt zu einer erh{\"o}hten Transpiration und somit einer K{\"u}hlung der Bl{\"a}tter. Der Abbau von Triacylglycerolen und St{\"a}rke am Morgen ist notwendig, um die Stomata zu {\"o}ffnen. Zus{\"a}tzlich dient der Abbau der Aufrechterhaltung des Citratzyklus und somit der Energieversorgung. In weiteren Experimenten konnte ich durch F{\"u}tterung mit stabil markierter Laurins{\"a}ure zeigen, dass die Triacylglycerole auch dem Aufbau neuer Aminos{\"a}uren unter Stressbedingungen dienen. Die hier vorgestellten Arbeiten bieten die Grundlage, um den Mechanismus der Thermotoleranz besser zu verstehen. Das Verst{\"a}ndnis der in dieser Arbeit beschriebenen molekularen Signalwege und Enzyme kann langfristig dazu beitragen hitzeresistentere Nutzpflanzen zu z{\"u}chten.}, subject = {Hitzestress}, language = {de} } @article{GoettlichKunzZappetal.2018, author = {G{\"o}ttlich, Claudia and Kunz, Meik and Zapp, Cornelia and Nietzer, Sarah L. and Walles, Heike and Dandekar, Thomas and Dandekar, Gudrun}, title = {A combined tissue-engineered/in silico signature tool patient stratification in lung cancer}, series = {Molecular Oncology}, volume = {12}, journal = {Molecular Oncology}, doi = {10.1002/1878-0261.12323}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233137}, pages = {1264-1285}, year = {2018}, abstract = {Patient-tailored therapy based on tumor drivers is promising for lung cancer treatment. For this, we combined in vitro tissue models with in silico analyses. Using individual cell lines with specific mutations, we demonstrate a generic and rapid stratification pipeline for targeted tumor therapy. We improve in vitro models of tissue conditions by a biological matrix-based three-dimensional (3D) tissue culture that allows in vitro drug testing: It correctly shows a strong drug response upon gefitinib (Gef) treatment in a cell line harboring an EGFR-activating mutation (HCC827), but no clear drug response upon treatment with the HSP90 inhibitor 17AAG in two cell lines with KRAS mutations (H441, A549). In contrast, 2D testing implies wrongly KRAS as a biomarker for HSP90 inhibitor treatment, although this fails in clinical studies. Signaling analysis by phospho-arrays showed similar effects of EGFR inhibition by Gef in HCC827 cells, under both 2D and 3D conditions. Western blot analysis confirmed that for 3D conditions, HSP90 inhibitor treatment implies different p53 regulation and decreased MET inhibition in HCC827 and H441 cells. Using in vitro data (western, phospho-kinase array, proliferation, and apoptosis), we generated cell line-specific in silico topologies and condition-specific (2D, 3D) simulations of signaling correctly mirroring in vitro treatment responses. Networks predict drug targets considering key interactions and individual cell line mutations using the Human Protein Reference Database and the COSMIC database. A signature of potential biomarkers and matching drugs improve stratification and treatment in KRAS-mutated tumors. In silico screening and dynamic simulation of drug actions resulted in individual therapeutic suggestions, that is, targeting HIF1A in H441 and LKB1 in A549 cells. In conclusion, our in vitro tumor tissue model combined with an in silico tool improves drug effect prediction and patient stratification. Our tool is used in our comprehensive cancer center and is made now publicly available for targeted therapy decisions.}, language = {en} } @article{GrebinykGrebinykPrylutskaetal.2018, author = {Grebinyk, Anna and Grebinyk, Sergii and Prylutska, Svitlana and Ritter, Uwe and Matyshevska, Olga and Dandekar, Thomas and Frohme, Marcus}, title = {C60 fullerene accumulation in human leukemic cells and perspectives of LED-mediated photodynamic therapy}, series = {Free Radical Biology and Medicine}, volume = {124}, journal = {Free Radical Biology and Medicine}, doi = {10.1016/j.freeradbiomed.2018.06.022}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228245}, pages = {319-327}, year = {2018}, abstract = {Recent progress in nanobiotechnology has attracted interest to a biomedical application of the carbon nanostructure C60 fullerene since it possesses a unique structure and versatile biological activity. C60 fullerene potential application in the frame of cancer photodynamic therapy (PDT) relies on rapid development of new light sources as well as on better understanding of the fullerene interaction with cells. The aim of this study was to analyze C60 fullerene effects on human leukemic cells (CCRF-CEM) in combination with high power single chip light-emitting diodes (LEDs) light irradiation of different wavelengths: ultraviolet (UV, 365 nm), violet (405 nm), green (515 nm) and red (632 nm). The time-dependent accumulation of fullerene C60 in CCRF-CEM cells up to 250 ng/106 cells at 24 h with predominant localization within mitochondria was demonstrated with immunocytochemical staining and liquid chromatography mass spectrometry. In a cell viability assay we studied photoexcitation of the accumulated C60 nanostructures with ultraviolet or violet LEDs and could prove that significant phototoxic effects did arise. A less pronounced C60 fullerene phototoxic effect was observed after irradiation with green, and no effect was detected with red light. A C60 fullerene photoactivation with violet light induced substantial ROS generation and apoptotic cell death, confirmed by caspase3/7 activation and plasma membrane phosphatidylserine externalization. Our work proved C60 fullerene ability to induce apoptosis of leukemic cells after photoexcitation with high power single chip 405 nm LED as a light source. This underlined the potential for application of C60 nanostructure as a photosensitizer for anticancer therapy.}, language = {en} } @article{MindenSchnetgerPufaletal.2018, author = {Minden, Vanessa and Schnetger, Bernhard and Pufal, Gesine and Leonhardt, Sara D.}, title = {Antibiotic-induced effects on scaling relationships and on plant element contents in herbs and grasses}, series = {Ecology and Evolution}, volume = {8}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.4168}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224094}, pages = {6699-6713}, year = {2018}, abstract = {Plant performance is correlated with element concentrations in plant tissue, which may be impacted by adverse chemical soil conditions. Antibiotics of veterinary origin can adversely affect plant performance. They are released to agricultural fields via grazing animals or manure, taken up by plants and may be stored, transformed or sequestered by plant metabolic processes. We studied the potential effects of three antibiotics (penicillin, sulfadiazine, and tetracycline) on plant element contents (macro- and microelements). Plant species included two herb species (Brassica napus and Capsella bursa-pastoris) and two grass species (Triticum aestivum and Apera spica-venti), representing two crop species and two noncrop species commonly found in field margins, respectively. Antibiotic concentrations were chosen as to reflect in vivo situations, that is, relatively low concentrations similar to those detected in soils. In a greenhouse experiment, plants were raised in soil spiked with antibiotics. After harvest, macro- and microelements in plant leaves, stems, and roots were determined (mg/g). Results indicate that antibiotics can affect element contents in plants. Penicillin exerted the greatest effect both on element contents and on scaling relationships of elements between plant organs. Roots responded strongest to antibiotics compared to stems and leaves. We conclude that antibiotics in the soil, even in low concentrations, lead to low-element homeostasis, altering the scaling relationships between roots and other plant organs, which may affect metabolic processes and ultimately the performance of a plant.}, language = {en} } @article{SteinStenchlyCoulibalyetal.2018, author = {Stein, Katharina and Stenchly, Kathrin and Coulibaly, Drissa and Pauly, Alain and Dimobe, Kangbeni and Steffan-Dewenter, Ingolf and Konat{\´e}, Souleymane and Goetze, Dethardt and Porembski, Stefan and Linsenmair, K. Eduard}, title = {Impact of human disturbance on bee pollinator communities in savanna and agricultural sites in Burkina Faso, West Africa}, series = {Ecology and Evolution}, volume = {8}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.4197}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239999}, pages = {6827-6838}, year = {2018}, abstract = {All over the world, pollinators are threatened by land-use change involving degradation of seminatural habitats or conversion into agricultural land. Such disturbance often leads to lowered pollinator abundance and/or diversity, which might reduce crop yield in adjacent agricultural areas. For West Africa, changes in bee communities across disturbance gradients from savanna to agricultural land are mainly unknown. In this study, we monitored for the impact of human disturbance on bee communities in savanna and crop fields. We chose three savanna areas of varying disturbance intensity (low, medium, and high) in the South Sudanian zone of Burkina Faso, based on land-use/land cover data via Landsat images, and selected nearby cotton and sesame fields. During 21 months covering two rainy and two dry seasons in 2014 and 2015, we captured bees using pan traps. Spatial and temporal patterns of bee species abundance, richness, evenness and community structure were assessed. In total, 35,469 bee specimens were caught on 12 savanna sites and 22 fields, comprising 97 species of 32 genera. Bee abundance was highest at intermediate disturbance in the rainy season. Species richness and evenness did not differ significantly. Bee communities at medium and highly disturbed savanna sites comprised only subsets of those at low disturbed sites. An across-habitat spillover of bees (mostly abundant social bee species) from savanna into crop fields was observed during the rainy season when crops are mass-flowering, whereas most savanna plants are not in bloom. Despite disturbance intensification, our findings suggest that wild bee communities can persist in anthropogenic landscapes and that some species even benefitted disproportionally. West African areas of crop production such as for cotton and sesame may serve as important food resources for bee species in times when resources in the savanna are scarce and receive at the same time considerable pollination service.}, language = {en} } @article{HartkeSprengerSahmetal.2019, author = {Hartke, Juliane and Sprenger, Philipp P. and Sahm, Jacqueline and Winterberg, Helena and Orivel, J{\´e}r{\^o}me and Baur, Hannes and Beuerle, Till and Schmitt, Thomas and Feldmeyer, Barbara and Menzel, Florian}, title = {Cuticular hydrocarbons as potential mediators of cryptic species divergence in a mutualistic ant association}, series = {Ecology and Evolution}, volume = {9}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.5464}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227857}, pages = {9160-9176}, year = {2019}, abstract = {Upon advances in sequencing techniques, more and more morphologically identical organisms are identified as cryptic species. Often, mutualistic interactions are proposed as drivers of diversification. Species of the neotropical parabiotic ant association between Crematogaster levior and Camponotus femoratus are known for highly diverse cuticular hydrocarbon (CHC) profiles, which in insects serve as desiccation barrier but also as communication cues. In the present study, we investigated the association of the ants' CHC profiles with genotypes and morphological traits, and discovered cryptic species pairs in both genera. To assess putative niche differentiation between the cryptic species, we conducted an environmental association study that included various climate variables, canopy cover, and mutualistic plant species. Although mostly sympatric, the two Camponotus species seem to prefer different climate niches. However in the two Crematogaster species, we could not detect any differences in niche preference. The strong differentiation in the CHC profiles may thus suggest a possible role during speciation itself either by inducing assortative mating or by reinforcing sexual selection after the speciation event. We did not detect any further niche differences in the environmental parameters tested. Thus, it remains open how the cryptic species avoid competitive exclusion, with scope for further investigations.}, language = {en} } @article{KoenigZundelKrimmeretal.2019, author = {K{\"o}nig, Kerstin and Zundel, Petra and Krimmer, Elena and K{\"o}nig, Christian and Pollmann, Marie and Gottlieb, Yuval and Steidle, Johannes L. M.}, title = {Reproductive isolation due to prezygotic isolation and postzygotic cytoplasmic incompatibility in parasitoid wasps}, series = {Ecology and Evolution}, volume = {9}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.5588}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222796}, pages = {10694-10706}, year = {2019}, abstract = {The reproductive barriers that prevent gene flow between closely related species are a major topic in evolutionary research. Insect clades with parasitoid lifestyle are among the most species-rich insects and new species are constantly described, indicating that speciation occurs frequently in this group. However, there are only very few studies on speciation in parasitoids. We studied reproductive barriers in two lineages of Lariophagus distinguendus (Chalcidoidea: Hymenoptera), a parasitoid wasp of pest beetle larvae that occur in human environments. One of the two lineages occurs in households preferably attacking larvae of the drugstore beetle Stegobium paniceum ("DB-lineage"), the other in grain stores with larvae of the granary weevil Sitophilus granarius as main host ("GW-lineage"). Between two populations of the DB-lineage, we identified slight sexual isolation as intraspecific barrier. Between populations from both lineages, we found almost complete sexual isolation caused by female mate choice, and postzygotic isolation, which is partially caused by cytoplasmic incompatibility induced by so far undescribed endosymbionts which are not Wolbachia or Cardinium. Because separation between the two lineages is almost complete, they should be considered as separate species according to the biological species concept. This demonstrates that cryptic species within parasitoid Hymenoptera also occur in Central Europe in close contact to humans.}, language = {en} } @article{KendallRaderGagicetal.2019, author = {Kendall, Liam K. and Rader, Romina and Gagic, Vesna and Cariveau, Daniel P. and Albrecht, Matthias and Baldock, Katherine C. R. and Freitas, Breno M. and Hall, Mark and Holzschuh, Andrea and Molina, Francisco P. and Morten, Joanne M. and Pereira, Janaely S. and Portman, Zachary M. and Roberts, Stuart P. M. and Rodriguez, Juanita and Russo, Laura and Sutter, Louis and Vereecken, Nicolas J. and Bartomeus, Ignasi}, title = {Pollinator size and its consequences: Robust estimates of body size in pollinating insects}, series = {Ecology and Evolution}, volume = {9}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.4835}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325705}, pages = {1702-1714}, year = {2019}, abstract = {Body size is an integral functional trait that underlies pollination-related ecological processes, yet it is often impractical to measure directly. Allometric scaling laws have been used to overcome this problem. However, most existing models rely upon small sample sizes, geographically restricted sampling and have limited applicability for non-bee taxa. Allometric models that consider biogeography, phylogenetic relatedness, and intraspecific variation are urgently required to ensure greater accuracy. We measured body size as dry weight and intertegular distance (ITD) of 391 bee species (4,035 specimens) and 103 hoverfly species (399 specimens) across four biogeographic regions: Australia, Europe, North America, and South America. We updated existing models within a Bayesian mixed-model framework to test the power of ITD to predict interspecific variation in pollinator dry weight in interaction with different co-variates: phylogeny or taxonomy, sexual dimorphism, and biogeographic region. In addition, we used ordinary least squares regression to assess intraspecific dry weight ~ ITD relationships for ten bees and five hoverfly species. Including co-variates led to more robust interspecific body size predictions for both bees and hoverflies relative to models with the ITD alone. In contrast, at the intraspecific level, our results demonstrate that the ITD is an inconsistent predictor of body size for bees and hoverflies. The use of allometric scaling laws to estimate body size is more suitable for interspecific comparative analyses than assessing intraspecific variation. Collectively, these models form the basis of the dynamic R package, "pollimetry," which provides a comprehensive resource for allometric pollination research worldwide.}, language = {en} } @article{HillaertHovestadtVandegehuchteetal.2018, author = {Hillaert, Jasmijn and Hovestadt, Thomas and Vandegehuchte, Martijn L. and Bonte, Dries}, title = {Size-dependent movement explains why bigger is better in fragmented landscapes}, series = {Ecology and Evolution}, volume = {8}, journal = {Ecology and Evolution}, doi = {10.1002/ece3.4524}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-320322}, pages = {10754-10767}, year = {2018}, abstract = {Body size is a fundamental trait known to allometrically scale with metabolic rate and therefore a key determinant of individual development, life history, and consequently fitness. In spatially structured environments, movement is an equally important driver of fitness. Because movement is tightly coupled with body size, we expect habitat fragmentation to induce a strong selection pressure on size variation across and within species. Changes in body size distributions are then, in turn, expected to alter food web dynamics. However, no consensus has been reached on how spatial isolation and resource growth affect consumer body size distributions. Our aim was to investigate how these two factors shape the body size distribution of consumers under scenarios of size-dependent and size-independent consumer movement by applying a mechanistic, individual-based resource-consumer model. We also assessed the consequences of altered body size distributions for important ecosystem traits such as resource abundance and consumer stability. Finally, we determined those factors that explain most variation in size distributions. We demonstrate that decreasing connectivity and resource growth select for communities (or populations) consisting of larger species (or individuals) due to strong selection for the ability to move over longer distances if the movement is size-dependent. When including size-dependent movement, intermediate levels of connectivity result in increases in local size diversity. Due to this elevated functional diversity, resource uptake is maximized at the metapopulation or metacommunity level. At these intermediate levels of connectivity, size-dependent movement explains most of the observed variation in size distributions. Interestingly, local and spatial stability of consumer biomass is lowest when isolation and resource growth are high. Finally, we highlight that size-dependent movement is of vital importance for the survival of populations or communities within highly fragmented landscapes. Our results demonstrate that considering size-dependent movement is essential to understand how habitat fragmentation and resource growth shape body size distributions—and the resulting metapopulation or metacommunity dynamics—of consumers.}, language = {en} } @article{MollKellnerLeonhardtetal.2018, author = {Moll, Julia and Kellner, Harald and Leonhardt, Sabrina and Stengel, Elisa and Dahl, Andreas and B{\"a}ssler, Claus and Buscot, Fran{\c{c}}ois and Hofrichter, Martin and Hoppe, Bj{\"o}rn}, title = {Bacteria inhabiting deadwood of 13 tree species are heterogeneously distributed between sapwood and heartwood}, series = {Environmental Microbiology}, volume = {20}, journal = {Environmental Microbiology}, doi = {10.1111/1462-2920.14376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224168}, pages = {3744-3756}, year = {2018}, abstract = {Deadwood represents an important structural component of forest ecosystems, where it provides diverse niches for saproxylic biota. Although wood-inhabiting prokaryotes are involved in its degradation, knowledge about their diversity and the drivers of community structure is scarce. To explore the effect of deadwood substrate on microbial distribution, the present study focuses on the microbial communities of deadwood logs from 13 different tree species investigated using an amplicon based deep-sequencing analysis. Sapwood and heartwood communities were analysed separately and linked to various relevant wood physico-chemical parameters. Overall, Proteobacteria, Acidobacteria and Actinobacteria represented the most dominant phyla. Microbial OTU richness and community structure differed significantly between tree species and between sapwood and heartwood. These differences were more pronounced for heartwood than for sapwood. The pH value and water content were the most important drivers in both wood compartments. Overall, investigating numerous tree species and two compartments provided a remarkably comprehensive view of microbial diversity in deadwood.}, language = {en} } @article{HilmersFriessBaessleretal.2018, author = {Hilmers, Torben and Friess, Nicolas and B{\"a}ssler, Claus and Heurich, Marco and Brandl, Roland and Pretzsch, Hans and Seidl, Rupert and M{\"u}ller, J{\"o}rg}, title = {Biodiversity along temperate forest succession}, series = {Journal of Applied Ecology}, volume = {55}, journal = {Journal of Applied Ecology}, doi = {10.1111/1365-2664.13238}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-320632}, pages = {2756-2766}, year = {2018}, abstract = {1. The successional dynamics of forests—from canopy openings to regeneration, maturation, and decay—influence the amount and heterogeneity of resources available for forest-dwelling organisms. Conservation has largely focused only on selected stages of forest succession (e.g., late-seral stages). However, to develop comprehensive conservation strategies and to understand the impact of forest management on biodiversity, a quantitative understanding of how different trophic groups vary over the course of succession is needed. 2. We classified mixed mountain forests in Central Europe into nine successional stages using airborne LiDAR. We analysed α- and β-diversity of six trophic groups encompassing approximately 3,000 species from three kingdoms. We quantified the effect of successional stage on the number of species with and without controlling for species abundances and tested whether the data fit the more-individuals hypothesis or the habitat heterogeneity hypothesis. Furthermore, we analysed the similarity of assemblages along successional development. 3. The abundance of producers, first-order consumers, and saprotrophic species showed a U-shaped response to forest succession. The number of species of producer and consumer groups generally followed this U-shaped pattern. In contrast to our expectation, the number of saprotrophic species did not change along succession. When we controlled for the effect of abundance, the number of producer and saproxylic beetle species increased linearly with forest succession, whereas the U-shaped response of the number of consumer species persisted. The analysis of assemblages indicated a large contribution of succession-mediated β-diversity to regional γ-diversity. 4. Synthesis and applications. Depending on the species group, our data supported both the more-individuals hypothesis and the habitat heterogeneity hypothesis. Our results highlight the strong influence of forest succession on biodiversity and underline the importance of controlling for successional dynamics when assessing biodiversity change in response to external drivers such as climate change. The successional stages with highest diversity (early and late successional stages) are currently strongly underrepresented in the forests of Central Europe. We thus recommend that conservation strategies aim at a more balanced representation of all successional stages.}, language = {en} } @article{BahramAnslanHildebrandetal.2019, author = {Bahram, Mohammad and Anslan, Sten and Hildebrand, Falk and Bork, Peer and Tedersoo, Leho}, title = {Newly designed 16S rRNA metabarcoding primers amplify diverse and novel archaeal taxa from the environment}, series = {Environmental Microbiology Reports}, volume = {11}, journal = {Environmental Microbiology Reports}, doi = {10.1111/1758-2229.12684}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221380}, pages = {487-494}, year = {2019}, abstract = {High-throughput studies of microbial communities suggest that Archaea are a widespread component of microbial diversity in various ecosystems. However, proper quantification of archaeal diversity and community ecology remains limited, as sequence coverage of Archaea is usually low owing to the inability of available prokaryotic primers to efficiently amplify archaeal compared to bacterial rRNA genes. To improve identification and quantification of Archaea, we designed and validated the utility of several primer pairs to efficiently amplify archaeal 16S rRNA genes based on up-to-date reference genes. We demonstrate that several of these primer pairs amplify phylogenetically diverse Archaea with high sequencing coverage, outperforming commonly used primers. Based on comparing the resulting long 16S rRNA gene fragments with public databases from all habitats, we found several novel family- to phylum-level archaeal taxa from topsoil and surface water. Our results suggest that archaeal diversity has been largely overlooked due to the limitations of available primers, and that improved primer pairs enable to estimate archaeal diversity more accurately.}, language = {en} } @article{MuellerNossThornetal.2019, author = {M{\"u}ller, J{\"o}rg and Noss, Reed F. and Thorn, Simon and B{\"a}ssler, Claus and Leverkus, Alexandro B. and Lindenmayer, David}, title = {Increasing disturbance demands new policies to conserve intact forest}, series = {Conservation Letters}, volume = {12}, journal = {Conservation Letters}, doi = {10.1111/conl.12449}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224256}, year = {2019}, abstract = {Ongoing controversy over logging the ancient Białowieża Forest in Poland symbolizes a global problem for policies and management of the increasing proportion of the earth's intact forest that is subject to postdisturbance logging. We review the extent of, and motivations for, postdisturbance logging in protected and unprotected forests globally. An unprecedented level of logging in protected areas and other places where green-tree harvest would not normally occur is driven by economic interests and a desire for pest control. To avoid failure of global initiatives dedicated to reducing the loss of species, five key policy reforms are necessary: (1) salvage logging must be banned from protected areas; (2) forest planning should address altered disturbance regimes for all intact forests to ensure that significant areas remain undisturbed by logging; (3) new kinds of integrated analyses are needed to assess the potential economic benefits of salvage logging against its ecological, economic, and social costs; (4) global and regional maps of natural disturbance regimes should be created to guide better spatiotemporal planning of protected areas and undisturbed forests outside reserves; and (5) improved education and communication programs are needed to correct widely held misconceptions about natural disturbances.}, language = {en} }