TY - JOUR A1 - Redlich, Sarah A1 - Martin, Emily A. A1 - Wende, Beate A1 - Steffan-Dewenter, Ingolf T1 - Landscape heterogeneity rather than crop diversity mediates bird diversity in agricultural landscapes JF - PLoS ONE N2 - Crop diversification has been proposed as farm management tool that could mitigate the externalities of conventional farming while reducing productivity-biodiversity trade-offs. Yet evidence for the acclaimed biodiversity benefits of landscape-level crop diversity is ambiguous. Effects may strongly depend on spatial scale and the level of landscape heterogeneity (e.g. overall habitat diversity). At the same time, contrasting within-taxon responses obscure benefits to specific functional groups (i.e. species with shared characteristics or requirements) if studied at the community level. The objectives of this study were to 1) disentangle the relative effects of crop diversity and landscape heterogeneity on avian species richness across five spatial scales ranging from 250 to 3000 m radii around focal winter wheat fields; and 2) assess whether functional groups (feeding guild, conservation status, habitat preference, nesting behaviour) determine the strength and direction of responses to crop diversity and landscape heterogeneity. In central Germany, 14 landscapes were selected along independent gradients of crop diversity (annual arable crops) and landscape heterogeneity. Bird species richness in each landscape was estimated using four point counts throughout the breeding season. We found no effects of landscape-level crop diversity on bird richness and functional groups. Instead, landscape heterogeneity was strongly associated with increased total bird richness across all spatial scales. In particular, insect-feeding and non-farmland birds were favoured in heterogeneous landscapes, as were species not classified as endangered or vulnerable on the regional Red List. Crop-nesting farmland birds, however, were less species-rich in these landscapes. Accordingly, crop diversification may be less suitable for conserving avian diversity and associated ecosystem services (e.g. biological pest control), although confounding interactions with management intensity need yet to be confirmed. In contrast, enhancement of landscape heterogeneity by increasing perennial habitat diversity, reducing field sizes and the amount of cropland has the potential to benefit overall bird richness. Specialist farmland birds, however, may require more targeted management approaches. KW - bird diversity KW - crop diversity KW - landscape heterogeneity Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177110 VL - 13 IS - 8 ER - TY - JOUR A1 - Audretsch, Christof A1 - Gratani, Fabio A1 - Wolz, Christiane A1 - Dandekar, Thomas T1 - Modeling of stringent-response reflects nutrient stress induced growth impairment and essential amino acids in different Staphylococcus aureus mutants JF - Scientific Reports N2 - Stapylococcus aureus colonises the nose of healthy individuals but can also cause a wide range of infections. Amino acid (AA) synthesis and their availability is crucial to adapt to conditions encountered in vivo. Most S. aureus genomes comprise all genes required for AA biosynthesis. Nevertheless, different strains require specific sets of AAs for growth. In this study we show that regulation inactivates pathways under certain conditions which result in these observed auxotrophies. We analyzed in vitro and modeled in silico in a Boolean semiquantitative model (195 nodes, 320 edges) the regulatory impact of stringent response (SR) on AA requirement in S. aureus HG001 (wild-type) and in mutant strains lacking the metabolic regulators RSH, CodY and CcpA, respectively. Growth in medium lacking single AAs was analyzed. Results correlated qualitatively to the in silico predictions of the final model in 92% and quantitatively in 81%. Remaining gaps in our knowledge are evaluated and discussed. This in silico model is made fully available and explains how integration of different inputs is achieved in SR and AA metabolism of S. aureus. The in vitro data and in silico modeling stress the role of SR and central regulators such as CodY for AA metabolisms in S. aureus. KW - bacteriology KW - cellular signalling networks Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260313 VL - 11 IS - 1 ER - TY - JOUR A1 - Goos, Carina A1 - Dejung, Mario A1 - Janzen, Christian J. A1 - Butter, Falk A1 - Kramer, Susanne T1 - The nuclear proteome of Trypanosoma brucei JF - PLoS ONE N2 - Trypanosoma brucei is a protozoan flagellate that is transmitted by tsetse flies into the mammalian bloodstream. The parasite has a huge impact on human health both directly by causing African sleeping sickness and indirectly, by infecting domestic cattle. The biology of trypanosomes involves some highly unusual, nuclear-localised processes. These include polycistronic transcription without classical promoters initiated from regions defined by histone variants, trans-splicing of all transcripts to the exon of a spliced leader RNA, transcription of some very abundant proteins by RNA polymerase I and antigenic variation, a switch in expression of the cell surface protein variants that allows the parasite to resist the immune system of its mammalian host. Here, we provide the nuclear proteome of procyclic Trypanosoma brucei, the stage that resides within the tsetse fly midgut. We have performed quantitative label-free mass spectrometry to score 764 significantly nuclear enriched proteins in comparison to whole cell lysates. A comparison with proteomes of several experimentally characterised nuclear and non-nuclear structures and pathways confirmed the high quality of the dataset: the proteome contains about 80% of all nuclear proteins and less than 2% false positives. Using motif enrichment, we found the amino acid sequence KRxR present in a large number of nuclear proteins. KRxR is a sub-motif of a classical eukaryotic monopartite nuclear localisation signal and could be responsible for nuclear localization of proteins in Kinetoplastida species. As a proof of principle, we have confirmed the nuclear localisation of six proteins with previously unknown localisation by expressing eYFP fusion proteins. While proteome data of several T. brucei organelles have been published, our nuclear proteome closes an important gap in knowledge to study trypanosome biology, in particular nuclear-related processes. KW - Trypanosoma KW - gambiense KW - Trypanosoma brucei KW - proteomes KW - yellow fluorescent protein KW - mitochondria KW - protein structure KW - histones Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158572 VL - 12 IS - 7 ER - TY - JOUR A1 - Groh, Claudia A1 - Rössler, Wolfgang T1 - Analysis of Synaptic Microcircuits in the Mushroom Bodies of the Honeybee JF - Insects N2 - Mushroom bodies (MBs) are multisensory integration centers in the insect brain involved in learning and memory formation. In the honeybee, the main sensory input region (calyx) of MBs is comparatively large and receives input from mainly olfactory and visual senses, but also from gustatory/tactile modalities. Behavioral plasticity following differential brood care, changes in sensory exposure or the formation of associative long-term memory (LTM) was shown to be associated with structural plasticity in synaptic microcircuits (microglomeruli) within olfactory and visual compartments of the MB calyx. In the same line, physiological studies have demonstrated that MB-calyx microcircuits change response properties after associative learning. The aim of this review is to provide an update and synthesis of recent research on the plasticity of microcircuits in the MB calyx of the honeybee, specifically looking at the synaptic connectivity between sensory projection neurons (PNs) and MB intrinsic neurons (Kenyon cells). We focus on the honeybee as a favorable experimental insect for studying neuronal mechanisms underlying complex social behavior, but also compare it with other insect species for certain aspects. This review concludes by highlighting open questions and promising routes for future research aimed at understanding the causal relationships between neuronal and behavioral plasticity in this charismatic social insect. KW - mushroom body KW - microglomeruli KW - projection neurons KW - Kenyon cells KW - dendritic specializations KW - structural synaptic plasticity KW - behavioral plasticity KW - vision KW - olfaction Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200774 SN - 2075-4450 VL - 11 IS - 1 ER - TY - JOUR A1 - Kaya-Zeeb, Sinan A1 - Delac, Saskia A1 - Wolf, Lena A1 - Marante, Ana Luiza A1 - Scherf-Clavel, Oliver A1 - Thamm, Markus T1 - Robustness of the honeybee neuro-muscular octopaminergic system in the face of cold stress JF - Frontiers in Physiology N2 - In recent decades, our planet has undergone dramatic environmental changes resulting in the loss of numerous species. This contrasts with species that can adapt quickly to rapidly changing ambient conditions, which require physiological plasticity and must occur rapidly. The Western honeybee (Apis mellifera) apparently meets this challenge with remarkable success, as this species is adapted to numerous climates, resulting in an almost worldwide distribution. Here, coordinated individual thermoregulatory activities ensure survival at the colony level and thus the transmission of genetic material. Recently, we showed that shivering thermogenesis, which is critical for honeybee thermoregulation, depends on octopamine signaling. In this study, we tested the hypothesis that the thoracic neuro-muscular octopaminergic system strives for a steady-state equilibrium under cold stress to maintain endogenous thermogenesis. We can show that this applies for both, octopamine provision by flight muscle innervating neurons and octopamine receptor expression in the flight muscles. Additionally, we discovered alternative splicing for AmOARβ2. At least the expression of one isoform is needed to survive cold stress conditions. We assume that the thoracic neuro-muscular octopaminergic system is finely tuned in order to contribute decisively to survival in a changing environment. KW - honeybees KW - thermogenesis KW - cold stress KW - octopamine KW - octopamine receptors KW - gene expression Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288753 SN - 1664-042X VL - 13 ER - TY - JOUR A1 - Villagomez, Gemma N. A1 - Nürnberger, Fabian A1 - Requier, Fabrice A1 - Schiele, Susanne A1 - Steffan-Dewenter, Ingo T1 - Effects of temperature and photoperiod on the seasonal timing of Western honey bee colonies and an early spring flowering plant JF - Ecology and Evolution N2 - Temperature and photoperiod are important Zeitgebers for plants and pollinators to synchronize growth and reproduction with suitable environmental conditions and their mutualistic interaction partners. Global warming can disturb this temporal synchronization since interacting species may respond differently to new combinations of photoperiod and temperature under future climates, but experimental studies on the potential phenological responses of plants and pollinators are lacking. We simulated current and future combinations of temperature and photoperiod to assess effects on the overwintering and spring phenology of an early flowering plant species (Crocus sieberi) and the Western honey bee (Apis mellifera). We could show that increased mean temperatures in winter and early spring advanced the flowering phenology of C. sieberi and intensified brood rearing activity of A. mellifera but did not advance their brood rearing activity. Flowering phenology of C. sieberi also relied on photoperiod, while brood rearing activity of A. mellifera did not. The results confirm that increases in temperature can induce changes in phenological responses and suggest that photoperiod can also play a critical role in these responses, with currently unknown consequences for real-world ecosystems in a warming climate. KW - Apis mellifera KW - climate change KW - rocus sieberi KW - phenology KW - plant–pollinator interaction KW - temporal mismatch Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258770 VL - 11 IS - 12 ER - TY - JOUR A1 - Kropf, Jan A1 - Rössler, Wolfgang T1 - In-situ recording of ionic currents in projection neurons and Kenyon cells in the olfactory pathway of the honeybee JF - PLoS ONE N2 - The honeybee olfactory pathway comprises an intriguing pattern of convergence and divergence: ~60.000 olfactory sensory neurons (OSN) convey olfactory information on ~900 projection neurons (PN) in the antennal lobe (AL). To transmit this information reliably, PNs employ relatively high spiking frequencies with complex patterns. PNs project via a dual olfactory pathway to the mushroom bodies (MB). This pathway comprises the medial (m-ALT) and the lateral antennal lobe tract (l-ALT). PNs from both tracts transmit information from a wide range of similar odors, but with distinct differences in coding properties. In the MBs, PNs form synapses with many Kenyon cells (KC) that encode odors in a spatially and temporally sparse way. The transformation from complex information coding to sparse coding is a well-known phenomenon in insect olfactory coding. Intrinsic neuronal properties as well as GABAergic inhibition are thought to contribute to this change in odor representation. In the present study, we identified intrinsic neuronal properties promoting coding differences between PNs and KCs using in-situ patch-clamp recordings in the intact brain. We found very prominent K+ currents in KCs clearly differing from the PN currents. This suggests that odor coding differences between PNs and KCs may be caused by differences in their specific ion channel properties. Comparison of ionic currents of m- and l-ALT PNs did not reveal any differences at a qualitative level. KW - action potentials KW - olfaction KW - honeybee Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175869 VL - 13 IS - 1 ER - TY - JOUR A1 - Schilcher, Felix A1 - Thamm, Markus A1 - Strube-Bloss, Martin A1 - Scheiner, Ricarda T1 - Opposing actions of octopamine and tyramine on honeybee vision JF - Biomolecules N2 - The biogenic amines octopamine and tyramine are important neurotransmitters in insects and other protostomes. They play a pivotal role in the sensory responses, learning and memory and social organisation of honeybees. Generally, octopamine and tyramine are believed to fulfil similar roles as their deuterostome counterparts epinephrine and norepinephrine. In some cases opposing functions of both amines have been observed. In this study, we examined the functions of tyramine and octopamine in honeybee responses to light. As a first step, electroretinography was used to analyse the effect of both amines on sensory sensitivity at the photoreceptor level. Here, the maximum receptor response was increased by octopamine and decreased by tyramine. As a second step, phototaxis experiments were performed to quantify the behavioural responses to light following treatment with either amine. Octopamine increased the walking speed towards different light sources while tyramine decreased it. This was independent of locomotor activity. Our results indicate that tyramine and octopamine act as functional opposites in processing responses to light. KW - biogenic amines KW - neurotransmitter KW - phototaxis KW - ERG KW - behaviour KW - modulation KW - visual system KW - octopamine KW - tyramine KW - Apis mellifera Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246214 SN - 2218-273X VL - 11 IS - 9 ER - TY - JOUR A1 - Fleischmann, Pauline N. A1 - Grob, Robin A1 - Rössler, Wolfgang T1 - Kompass im Kopf : wie Wüstenameisen lernen heimzukehren JF - Biologie in unserer Zeit N2 - Erfolgreiche räumliche Orientierung ist für viele Tiere eine alltägliche Herausforderung. Cataglyphis‐Wüstenameisen sind bekannt für ihre Navigationsfähigkeiten, mit deren Hilfe sie nach langen Futtersuchläufen problemlos zum Nest zurückfinden. Wie aber nehmen naive Ameisen ihre Navigationssysteme in Betrieb? Nach mehrwöchigem Innendienst im dunklen Nest werden sie zu Sammlerinnen bei hellem Sonnenschein. Dieser Wechsel erfordert einen drastischen Wandel im Verhalten sowie neuronale Veränderungen im Gehirn. Erfahrene Ameisen orientieren sich vor allem visuell, sie nutzen einen Himmelskompass und Landmarkenpanoramen. Daher absolvieren naive Ameisen stereotype Lernläufe, um ihren Kompass zu kalibrieren und die Nestumgebung kennenzulernen. Während der Lernläufe blicken sie wiederholt zum Nesteingang zurück und prägen sich so ihren Heimweg ein. Zur Ausrichtung ihrer Blicke nutzen sie das Erdmagnetfeld als Kompassreferenz. Cataglyphis‐Ameisen besitzen hierfür einen Magnetkompass, der bislang unbekannt war. N2 - Successful spatial orientation is a daily challenge for many animals. Cataglyphis desert ants are famous for their navi­gational performances. They return to the nest after exten­sive foraging trips without any problems. How do ants take their navigational systems into operation? After conducting different tasks in the dark nest for several weeks, they be­come foragers under bright sun light. This transition re­quires both a drastic switch in behavior and neuronal changes in the brain. Experienced foragers mainly rely on visual cues. They use a celestial compass and landmark panoramas. For that reason, naïve ants perform stereotype learning walks to calibrate their compass systems and ac­quire information about the nest’s surroundings. During their learning walks, the ants frequently look back to the nest entrance to learn the homing direction. For aligning their gazes, they use the earth’s magnetic field as a com­pass reference. This magnetic compass in Cataglyphis ants was previously unknown. KW - Cataglyphis-Wüstenameisen KW - Magnetkompass KW - Insektennavigation KW - Himmelskompass Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219260 SN - 1521-415X VL - 50 IS - 2 ER - TY - JOUR A1 - Hesselbach, Hannah A1 - Scheiner, Ricarda T1 - Effects of the novel pesticide flupyradifurone (Sivanto) on honeybee taste and cognition JF - Scientific Reports N2 - Due to intensive agriculture honeybees are threatened by various pesticides. The use of one group of them, the neonicotinoids, was recently restricted by the European Union. These chemicals bind to the nicotinic acetylcholine receptor (nAchR) in the honeybee brain. Recently, Bayer AG released a new pesticide by the name of “Sivanto” against sucking insects. It is assumed to be harmless for honeybees, although its active ingredient, flupyradifurone, binds nAchR similar to the neonicotinoids. We investigated if this pesticide affects the taste for sugar and cognitive performance in honeybee foragers. These bees are directly exposed to the pesticide while foraging for pollen or nectar. Our results demonstrate that flupyradifurone can reduce taste and appetitive learning performance in honeybees foraging for pollen and nectar, although only the highest concentration had significant effects. Most likely, honeybee foragers will not be exposed to these high concentrations. Therefore, the appropriate use of this pesticide is considered safe for honeybees, at least with respect to the behaviors studied here. KW - animal behaviour KW - chemical ecology KW - pesticide KW - honeybee KW - taste KW - cognition KW - flupyradifurone Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175853 VL - 8 IS - 4954 ER - TY - JOUR A1 - Sbirkov, Yordan A1 - Kwok, Colin A1 - Bhamra, Amandeep A1 - Thompson, Andrew J. A1 - Gil, Veronica A1 - Zelent, Arthur A1 - Petrie, Kevin T1 - Semi-quantitative mass spectrometry in AML cells identifies new non-genomic targets of the EZH2 methyltransferase JF - International Journal of Molecular Sciences N2 - Alterations to the gene encoding the EZH2 (KMT6A) methyltransferase, including both gain-of-function and loss-of-function, have been linked to a variety of haematological malignancies and solid tumours, suggesting a complex, context-dependent role of this methyltransferase. The successful implementation of molecularly targeted therapies against EZH2 requires a greater understanding of the potential mechanisms by which EZH2 contributes to cancer. One aspect of this effort is the mapping of EZH2 partner proteins and cellular targets. To this end we performed affinity-purification mass spectrometry in the FAB-M2 HL-60 acute myeloid leukaemia (AML) cell line before and after all-trans retinoic acid-induced differentiation. These studies identified new EZH2 interaction partners and potential non-histone substrates for EZH2-mediated methylation. Our results suggest that EZH2 is involved in the regulation of translation through interactions with a number of RNA binding proteins and by methylating key components of protein synthesis such as eEF1A1. Given that deregulated mRNA translation is a frequent feature of cancer and that eEF1A1 is highly expressed in many human tumours, these findings present new possibilities for the therapeutic targeting of EZH2 in AML. KW - acute myeloid leukaemia KW - EZH2 KW - mass spectrometry KW - methylation KW - eEF1A1 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285541 SN - 1422-0067 VL - 18 IS - 7 ER - TY - JOUR A1 - Gulve, Nitish A1 - Frank, Celina A1 - Klepsch, Maximilian A1 - Prusty, Bhupesh K. T1 - Chromosomal integration of HHV-6A during non-productive viral infection JF - Scientific Reports N2 - Human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) are two different species of betaherpesviruses that integrate into sub-telomeric ends of human chromosomes, for which different prevalence rates of integration have been reported. It has been demonstrated that integrated viral genome is stable and is fully retained. However, study of chromosomally integrated viral genome in individuals carrying inherited HHV-6 (iciHHV-6) showed unexpected number of viral DR copies. Hence, we created an in vitro infection model and studied retention of full or partial viral genome over a period of time. We observed an exceptional event where cells retained viral direct repeats (DRs) alone in the absence of the full viral genome. Finally, we found evidence for non-telomeric integration of HHV-6A DR in both cultured cells and in an iciHHV-6 individual. Our results shed light on several novel features of HHV-6A chromosomal integration and provide valuable information for future screening techniques. KW - herpes virus KW - infectious-disease diagnostics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158117 VL - 7 IS - 512 ER - TY - JOUR A1 - Akhoon, Bashir A. A1 - Gupta, Shishir K. A1 - Tiwari, Sudeep A1 - Rathor, Laxmi A1 - Pant, Aakanksha A1 - Singh, Nivedita A1 - Gupta, Shailendra K. A1 - Dandekar, Thomas A1 - Pandey, Rakesh T1 - C. elegans protein interaction network analysis probes RNAi validated pro-longevity effect of nhr-6, a human homolog of tumor suppressor Nr4a1 JF - Scientific Reports N2 - Protein-protein interaction (PPI) studies are gaining momentum these days due to the plethora of various high-throughput experimental methods available for detecting PPIs. Proteins create complexes and networks by functioning in harmony with other proteins and here in silico network biology hold the promise to reveal new functionality of genes as it is very difficult and laborious to carry out experimental high-throughput genetic screens in living organisms. We demonstrate this approach by computationally screening C. elegans conserved homologs of already reported human tumor suppressor and aging associated genes. We select by this nhr-6, vab-3 and gst-23 as predicted longevity genes for RNAi screen. The RNAi results demonstrated the pro-longevity effect of these genes. Nuclear hormone receptor nhr-6 RNAi inhibition resulted in a C. elegans phenotype of 23.46% lifespan reduction. Moreover, we show that nhr-6 regulates oxidative stress resistance in worms and does not affect the feeding behavior of worms. These findings imply the potential of nhr-6 as a common therapeutic target for aging and cancer ailments, stressing the power of in silico PPI network analysis coupled with RNAi screens to describe gene function. KW - Computer modelling KW - Embryonic induction KW - RNAi Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202666 VL - 9 ER - TY - JOUR A1 - Nguyen, Tu Anh Thi A1 - Beetz, M. Jerome A1 - Merlin, Christine A1 - Pfeiffer, Keram A1 - el Jundi, Basil T1 - Weighting of celestial and terrestrial cues in the monarch butterfly central complex JF - Frontiers in Neural Circuits N2 - Monarch butterflies rely on external cues for orientation during their annual long-distance migration from Northern US and Canada to Central Mexico. These external cues can be celestial cues, such as the sun or polarized light, which are processed in a brain region termed the central complex (CX). Previous research typically focused on how individual simulated celestial cues are encoded in the butterfly's CX. However, in nature, the butterflies perceive several celestial cues at the same time and need to integrate them to effectively use the compound of all cues for orientation. In addition, a recent behavioral study revealed that monarch butterflies can rely on terrestrial cues, such as the panoramic skyline, for orientation and use them in combination with the sun to maintain a directed flight course. How the CX encodes a combination of celestial and terrestrial cues and how they are weighted in the butterfly's CX is still unknown. Here, we examined how input neurons of the CX, termed TL neurons, combine celestial and terrestrial information. While recording intracellularly from the neurons, we presented a sun stimulus and polarized light to the butterflies as well as a simulated sun and a panoramic scene simultaneously. Our results show that celestial cues are integrated linearly in these cells, while the combination of the sun and a panoramic skyline did not always follow a linear integration of action potential rates. Interestingly, while the sun and polarized light were invariantly weighted between individual neurons, the sun stimulus and panoramic skyline were dynamically weighted when both stimuli were simultaneously presented. Taken together, this dynamic weighting between celestial and terrestrial cues may allow the butterflies to flexibly set their cue preference during navigation. KW - insect KW - central complex KW - navigation KW - orientation KW - landmark KW - migration KW - panorama KW - lepidoptera Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-279445 SN - 1662-5110 VL - 16 ER - TY - JOUR A1 - Vansynghel, Justine A1 - Ocampo-Ariza, Carolina A1 - Maas, Bea A1 - Martin, Emily A. A1 - Thomas, Evert A1 - Hanf-Dressler, Tara A1 - Schumacher, Nils-Christian A1 - Ulloque-Samatelo, Carlos A1 - Tscharntke, Teja A1 - Steffan-Dewenter, Ingolf T1 - Cacao flower visitation: Low pollen deposition, low fruit set and dominance of herbivores JF - Ecological Solutions and Evidence N2 - 1. Pollination services of cacao are crucial for global chocolate production, yet remain critically understudied, particularly in regions of origin of the species. Notably, uncertainties remain concerning the identity of cacao pollinators, the influence of landscape (forest distance) and management (shade cover) on flower visitation and the role of pollen deposition in limiting fruit set. 2. Here, we aimed to improve understanding of cacao pollination by studying limiting factors of fruit set in Peru, part of the centre of origin of cacao. Flower visitors were sampled with sticky insect glue in 20 cacao agroforests in two biogeographically distinct regions of Peru, across gradients of shade cover and forest distance. Further, we assessed pollen quantities and compared fruit set between naturally and manually pollinated flowers. 3. The most abundant flower visitors were aphids, ants and thrips in the north and thrips, midges and parasitoid wasps in the south of Peru. We present some evidence of increasing visitation rates from medium to high shade (40%–95% canopy closure) in the dry north, and opposite patterns in the semi-humid south, during the wet season. 4. Natural pollination resulted in remarkably low fruit set rates (2%), and very low pollen deposition. After hand pollination, fruit set more than tripled (7%), but was still low. 5. The diversity and high relative abundances of herbivore flower visitors limit our ability to draw conclusions on the functional role of different flower visitors. The remarkably low fruit set of naturally and even hand pollinated flowers indicates that other unaddressed factors limit cacao fruit production. Such factors could be, amongst others, a lack of effective pollinators, genetic incompatibility or resource limitation. Revealing efficient pollinator species and other causes of low fruit set rates is therefore key to establish location-specific management strategies and develop high yielding native cacao agroforestry systems in regions of origin of cacao KW - agroforestry KW - cocoa KW - flower visitors KW - forest proximity KW - hand pollination KW - pollen KW - pollination services KW - shade cover Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312722 SN - 2688-8319 VL - 3 IS - 2 ER - TY - JOUR A1 - Ruedenauer, Fabian A. A1 - Raubenheimer, David A1 - Kessner-Beierlein, Daniela A1 - Grund-Mueller, Nils A1 - Noack, Lisa A1 - Spaethe, Johannes A1 - Leonhardt, Sara D. T1 - Best be(e) on low fat: linking nutrient perception, regulation and fitness JF - Ecology Letters N2 - Preventing malnutrition through consuming nutritionally appropriate resources represents a challenge for foraging animals. This is due to often high variation in the nutritional quality of available resources. Foragers consequently need to evaluate different food sources. However, even the same food source can provide a plethora of nutritional and non‐nutritional cues, which could serve for quality assessment. We show that bumblebees, Bombus terrestris , overcome this challenge by relying on lipids as nutritional cue when selecting pollen. The bees ‘prioritised’ lipid perception in learning experiments and avoided lipid consumption in feeding experiments, which supported survival and reproduction. In contrast, survival and reproduction were severely reduced by increased lipid contents. Our study highlights the importance of fat regulation for pollen foraging bumblebees. It also reveals that nutrient perception, nutrient regulation and reproductive fitness can be linked, which represents an effective strategy enabling quick foraging decisions that prevent malnutrition and maximise fitness. KW - bee decline KW - foraging KW - nutrition KW - plant-insect interactions KW - pollen quality KW - PER KW - resource use Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208709 VL - 23 IS - 3 ER - TY - JOUR A1 - Fathy, Moustafa A1 - Fawzy, Michael Atef A1 - Hintzsche, Henning A1 - Nikaido, Toshio A1 - Dandekar, Thomas A1 - Othman, Eman M. T1 - Eugenol exerts apoptotic effect and modulates the sensitivity of HeLa cells to cisplatin and radiation JF - Molecules N2 - Eugenol is a phytochemical present in different plant products, e.g., clove oil. Traditionally, it is used against a number of different disorders and it was suggested to have anticancer activity. In this study, the activity of eugenol was evaluated in a human cervical cancer (HeLa) cell line and cell proliferation was examined after treatment with various concentrations of eugenol and different treatment durations. Cytotoxicity was tested using lactate dehydrogenase (LDH) enzyme leakage. In order to assess eugenol’s potential to act synergistically with chemotherapy and radiotherapy, cell survival was calculated after eugenol treatment in combination with cisplatin and X-rays. To elucidate its mechanism of action, caspase-3 activity was analyzed and the expression of various genes and proteins was checked by RT-PCR and western blot analyses. Eugenol clearly decreased the proliferation rate and increased LDH release in a concentration- and time-dependent manner. It showed synergistic effects with cisplatin and X-rays. Eugenol increased caspase-3 activity and the expression of Bax, cytochrome c (Cyt-c), caspase-3, and caspase-9 and decreased the expression of B-cell lymphoma (Bcl)-2, cyclooxygenase-2 (Cox-2), and interleukin-1 beta (IL-1β) indicating that eugenol mainly induced cell death by apoptosis. In conclusion, eugenol showed antiproliferative and cytotoxic effects via apoptosis and also synergism with cisplatin and ionizing radiation in the human cervical cancer cell line. KW - eugenol KW - HeLa cells KW - cisplatin KW - radiation KW - apoptosis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193227 SN - 1420-3049 VL - 24 IS - 21 ER - TY - JOUR A1 - Sarukhanyan, Edita A1 - Shityakov, Sergey A1 - Dandekar, Thomas T1 - In silico designed Axl receptor blocking drug candidates against Zika virus infection JF - ACS Omega N2 - After a large outbreak in Brazil, novel drugs against Zika virus became extremely necessary. Evaluation of virus-based pharmacological strategies concerning essential host factors brought us to the idea that targeting the Axl receptor by blocking its dimerization function could be critical for virus entry. Starting from experimentally validated compounds, such as RU-301, RU-302, warfarin, and R428, we identified a novel compound 2′ (R428 derivative) to be the most potent for this task amongst a number of alternative compounds and leads. The improved affinity of compound 2′ was confirmed by molecular docking as well as molecular dynamics simulation techniques using implicit solvation models. The current study summarizes a new possibility for inhibition of the Axl function as a potential target for future antiviral therapies. KW - free energy KW - molecular docking KW - molecular dynamics KW - simulation KW - pharmacology KW - proteins KW - structure-activity relationship KW - viruses KW - Zika virus Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176739 VL - 3 IS - 5 ER - TY - JOUR A1 - Reuter, Isabel A1 - Jäckels, Jana A1 - Kneitz, Susanne A1 - Kuper, Jochen A1 - Lesch, Klaus-Peter A1 - Lillesaar, Christina T1 - Fgf3 is crucial for the generation of monoaminergic cerebrospinal fluid contacting cells in zebrafish JF - Biology Open N2 - In most vertebrates, including zebrafish, the hypothalamic serotonergic cerebrospinal fluid-contacting (CSF-c) cells constitute a prominent population. In contrast to the hindbrain serotonergic neurons, little is known about the development and function of these cells. Here, we identify fibroblast growth factor (Fgf)3 as the main Fgf ligand controlling the ontogeny of serotonergic CSF-c cells. We show that fgf3 positively regulates the number of serotonergic CSF-c cells, as well as a subset of dopaminergic and neuroendocrine cells in the posterior hypothalamus via control of proliferation and cell survival. Further, expression of the ETS-domain transcription factor etv5b is downregulated after fgf3 impairment. Previous findings identified etv5b as critical for the proliferation of serotonergic progenitors in the hypothalamus, and therefore we now suggest that Fgf3 acts via etv5b during early development to ultimately control the number of mature serotonergic CSF-c cells. Moreover, our analysis of the developing hypothalamic transcriptome shows that the expression of fgf3 is upregulated upon fgf3 loss-of-function, suggesting activation of a self-compensatory mechanism. Together, these results highlight Fgf3 in a novel context as part of a signalling pathway of critical importance for hypothalamic development. KW - Fgf-signalling KW - Serotonin KW - Dopamine KW - Hypothalamus KW - Central nervous system Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200749 VL - 8 ER - TY - JOUR A1 - Kunz, Tobias C. A1 - Götz, Ralph A1 - Sauer, Markus A1 - Rudel, Thomas T1 - Detection of chlamydia developmental forms and secreted effectors by expansion microscopy JF - Frontiers in Cellular and Infection Microbiology N2 - Expansion microscopy (ExM) is a novel tool to improve the resolution of fluorescence-based microscopy that has not yet been used to visualize intracellular pathogens. Here we show the expansion of the intracellular pathogen Chlamydia trachomatis, enabling to differentiate its two distinct forms, catabolic active reticulate bodies (RB) and infectious elementary bodies (EB), on a conventional confocal microscope. We show that ExM enables the possibility to precisely locate chlamydial effector proteins, such as CPAF or Cdu1, within and outside of the chlamydial inclusion. Thus, we claim that ExM offers the possibility to address a broad range of questions and may be useful for further research on various intracellular pathogens. KW - expansion microscopy KW - chlamydia KW - secreted effectors KW - developmental forms KW - superresolution KW - imaging Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195716 SN - 2235-2988 VL - 9 IS - 276 ER - TY - JOUR A1 - Goos, Carina A1 - Dejung, Mario A1 - Wehman, Ann M. A1 - M-Natus, Elisabeth A1 - Schmidt, Johannes A1 - Sunter, Jack A1 - Engstler, Markus A1 - Butter, Falk A1 - Kramer, Susanne T1 - Trypanosomes can initiate nuclear export co-transcriptionally JF - Nucleic Acids Research N2 - The nuclear envelope serves as important messenger RNA (mRNA) surveillance system. In yeast and human, several control systems act in parallel to prevent nuclear export of unprocessed mRNAs. Trypanosomes lack homologues to most of the involved proteins and their nuclear mRNA metabolism is non-conventional exemplified by polycistronic transcription and mRNA processing by trans-splicing. We here visualized nuclear export in trypanosomes by intra- and intermolecular multi-colour single molecule FISH. We found that, in striking contrast to other eukaryotes, the initiation of nuclear export requires neither the completion of transcription nor splicing. Nevertheless, we show that unspliced mRNAs are mostly prevented from reaching the nucleus-distant cytoplasm and instead accumulate at the nuclear periphery in cytoplasmic nuclear periphery granules (NPGs). Further characterization of NPGs by electron microscopy and proteomics revealed that the granules are located at the cytoplasmic site of the nuclear pores and contain most cytoplasmic RNA-binding proteins but none of the major translation initiation factors, consistent with a function in preventing faulty mRNAs from reaching translation. Our data indicate that trypanosomes regulate the completion of nuclear export, rather than the initiation. Nuclear export control remains poorly understood, in any organism, and the described way of control may not be restricted to trypanosomes. KW - molecular biology KW - nuclear export KW - trypanosomes KW - mRNA KW - nuclear envelope Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177709 VL - 47 IS - 1 ER - TY - JOUR A1 - Zimmermann, Henriette A1 - Subota, Ines A1 - Batram, Christopher A1 - Kramer, Susanne A1 - Janzen, Christian J. A1 - Jones, Nicola G. A1 - Engstler, Markus T1 - A quorum sensing-independent path to stumpy development in Trypanosoma brucei JF - PLoS Pathogens N2 - For persistent infections of the mammalian host, African trypanosomes limit their population size by quorum sensing of the parasite-excreted stumpy induction factor (SIF), which induces development to the tsetse-infective stumpy stage. We found that besides this cell density-dependent mechanism, there exists a second path to the stumpy stage that is linked to antigenic variation, the main instrument of parasite virulence. The expression of a second variant surface glycoprotein (VSG) leads to transcriptional attenuation of the VSG expression site (ES) and immediate development to tsetse fly infective stumpy parasites. This path is independent of SIF and solely controlled by the transcriptional status of the ES. In pleomorphic trypanosomes varying degrees of ES-attenuation result in phenotypic plasticity. While full ES-attenuation causes irreversible stumpy development, milder attenuation may open a time window for rescuing an unsuccessful antigenic switch, a scenario that so far has not been considered as important for parasite survival. KW - Trypanosoma KW - hyperexpression techniques KW - parasitic cell cycles KW - cloning KW - cell cycle and cell division KW - cell differentiation KW - tetracyclines KW - parasitic diseases Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158230 VL - 13 IS - 4 ER - TY - JOUR A1 - Bae, Soyeon A1 - Müller, Jörg A1 - Förster, Bernhard A1 - Hilmers, Torben A1 - Hochrein, Sophia A1 - Jacobs, Martin A1 - Leroy, Benjamin M. L. A1 - Pretzsch, Hans A1 - Weisser, Wolfgang W. A1 - Mitesser, Oliver T1 - Tracking the temporal dynamics of insect defoliation by high‐resolution radar satellite data JF - Methods in Ecology and Evolution N2 - Quantifying tree defoliation by insects over large areas is a major challenge in forest management, but it is essential in ecosystem assessments of disturbance and resistance against herbivory. However, the trajectory from leaf-flush to insect defoliation to refoliation in broadleaf trees is highly variable. Its tracking requires high temporal- and spatial-resolution data, particularly in fragmented forests. In a unique replicated field experiment manipulating gypsy moth Lymantria dispar densities in mixed-oak forests, we examined the utility of publicly accessible satellite-borne radar (Sentinel-1) to track the fine-scale temporal trajectory of defoliation. The ratio of backscatter intensity between two polarizations from radar data of the growing season constituted a canopy development index (CDI) and a normalized CDI (NCDI), which were validated by optical (Sentinel-2) and terrestrial laser scanning (TLS) data as well by intensive caterpillar sampling from canopy fogging. The CDI and NCDI strongly correlated with optical and TLS data (Spearman's ρ = 0.79 and 0.84, respectively). The ΔNCDII\(_{Defoliation(A−C)}\) significantly explained caterpillar abundance (R\(^{2}\) = 0.52). The NCDI at critical timesteps and ΔNCDI related to defoliation and refoliation well discriminated between heavily and lightly defoliated forests. We demonstrate that the high spatial and temporal resolution and the cloud independence of Sentinel-1 radar potentially enable spatially unrestricted measurements of the highly dynamic canopy herbivory. This can help monitor insect pests, improve the prediction of outbreaks and facilitate the monitoring of forest disturbance, one of the high priority Essential Biodiversity Variables, in the near future. KW - Sentinel-1 KW - canopy herbivory KW - defoliation severity KW - gypsy moth KW - insect disturbance KW - intra-annual time-series KW - Lymantria dispar KW - remote sensing Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258222 VL - 13 IS - 1 ER - TY - JOUR A1 - Ambrožová, Lucie A1 - Finnberg, Sven A1 - Feldmann, Benedikt A1 - Buse, Jörn A1 - Preuss, Henry A1 - Ewald, Jörg A1 - Thorn, Simon T1 - Coppicing and topsoil removal promote diversity of dung‐inhabiting beetles (Coleoptera: Scarabaeidae, Geotrupidae, Staphylinidae) in forests JF - Agricultural and Forest Entomology N2 - Central European forests experience a substantial loss of open-forest organisms due to forest management and increasing nitrogen deposition. However, management strategies, removing different levels of nitrogen, have been rarely evaluated simultaneously. We tested the additive effects of coppicing and topsoil removal on communities of dung-inhabiting beetles compared to closed forests. We sampled 57 021 beetles, using baited pitfall traps exposed on 27 plots. Experimental treatments resulted in significantly different communities by promoting open-habitat species. While alpha diversity did not differ among treatments, gamma diversity of Geotrupidae and Scarabaeidae and beta diversity of Staphylinidae were higher in coppice than in forest. Functional diversity of rove beetles was higher in both, coppice and topsoil-removed plots, compared to control plots. This was likely driven by higher habitat heterogeneity in established forest openings. Five dung beetle species and four rove beetle species benefitted from coppicing, one red-listed dung beetle and two rove beetle species benefitted from topsoil removal. Our results demonstrate that dung-inhabiting beetles related to open forest patches can be promoted by both, coppicing and additional topsoil removal. A mosaic of coppice and bare-soil-rich patches can hence promote landscape-level gamma diversity of dung and rove beetles within forests. KW - nitrogen uptake KW - dung beetle KW - forest management KW - functional diversity KW - insect decline KW - rove beetle Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258296 VL - 24 IS - 1 ER - TY - JOUR A1 - Dühring, Sybille A1 - Germerodt, Sebastian A1 - Skerka, Christine A1 - Zipfel, Peter F. A1 - Dandekar, Thomas A1 - Schuster, Stefan T1 - Host-pathogen interactions between the human innate immune system and Candida albicans - understanding and modeling defense and evasion strategies JF - Frontiers in Microbiology N2 - The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given. KW - agent-based model KW - antimicrobial peptides KW - fungal pathogens KW - Candida albicans KW - immunological cross-talk KW - beta-lactamase inhibition KW - in vitro KW - biomaterial surfaces KW - biofilm formation KW - dendritic cells KW - infection KW - resistance KW - human immune system KW - host-pathogen interaction KW - computational systems biology KW - defense and evasion strategies Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151621 VL - 6 IS - 625 ER - TY - JOUR A1 - Scholz, Nicole A1 - Guan, Chonglin A1 - Nieberler, Matthias A1 - Grotmeyer, Alexander A1 - Maiellaro, Isabella A1 - Gao, Shiqiang A1 - Beck, Sebastian A1 - Pawlak, Matthias A1 - Sauer, Markus A1 - Asan, Esther A1 - Rothemund, Sven A1 - Winkler, Jana A1 - Prömel, Simone A1 - Nagel, Georg A1 - Langenhan, Tobias A1 - Kittel, Robert J T1 - Mechano-dependent signaling by Latrophilin/CIRL quenches cAMP in proprioceptive neurons JF - eLife N2 - Adhesion-type G protein-coupled receptors (aGPCRs), a large molecule family with over 30 members in humans, operate in organ development, brain function and govern immunological responses. Correspondingly, this receptor family is linked to a multitude of diverse human diseases. aGPCRs have been suggested to possess mechanosensory properties, though their mechanism of action is fully unknown. Here we show that the Drosophila aGPCR Latrophilin/dCIRL acts in mechanosensory neurons by modulating ionotropic receptor currents, the initiating step of cellular mechanosensation. This process depends on the length of the extended ectodomain and the tethered agonist of the receptor, but not on its autoproteolysis, a characteristic biochemical feature of the aGPCR family. Intracellularly, dCIRL quenches cAMP levels upon mechanical activation thereby specifically increasing the mechanosensitivity of neurons. These results provide direct evidence that the aGPCR dCIRL acts as a molecular sensor and signal transducer that detects and converts mechanical stimuli into a metabotropic response. KW - Latrophilin KW - adhesion GPCR KW - dCIRL KW - sensory physiology KW - metabotropic signalling KW - mechanotransduction Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170520 VL - 6 IS - e28360 ER - TY - JOUR A1 - Grob, Robin A1 - Heinig, Niklas A1 - Grübel, Kornelia A1 - Rössler, Wolfgang A1 - Fleischmann, Pauline N. T1 - Sex-specific and caste-specific brain adaptations related to spatial orientation in Cataglyphis ants JF - Journal of Comparative Neurology N2 - Cataglyphis desert ants are charismatic central place foragers. After long-ranging foraging trips, individual workers navigate back to their nest relying mostly on visual cues. The reproductive caste faces other orientation challenges, i.e. mate finding and colony foundation. Here we compare brain structures involved in spatial orientation of Cataglyphis nodus males, gynes, and foragers by quantifying relative neuropil volumes associated with two visual pathways, and numbers and volumes of antennal lobe (AL) olfactory glomeruli. Furthermore, we determined absolute numbers of synaptic complexes in visual and olfactory regions of the mushroom bodies (MB) and a major relay station of the sky-compass pathway to the central complex (CX). Both female castes possess enlarged brain centers for sensory integration, learning, and memory, reflected in voluminous MBs containing about twice the numbers of synaptic complexes compared with males. Overall, male brains are smaller compared with both female castes, but the relative volumes of the optic lobes and CX are enlarged indicating the importance of visual guidance during innate behaviors. Male ALs contain greatly enlarged glomeruli, presumably involved in sex-pheromone detection. Adaptations at both the neuropil and synaptic levels clearly reflect differences in sex-specific and caste-specific demands for sensory processing and behavioral plasticity underlying spatial orientation. KW - antennal lobe KW - synaptic plasticity KW - polymorphism KW - optic lobes KW - mushroom bodies KW - learning and memory KW - central complex Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257299 VL - 529 IS - 18 ER - TY - JOUR A1 - Leverkus, Alexandro B A1 - Gustafsson, Lena A1 - Lindenmayer, David B A1 - Castro, Jorge A1 - Rey Benayas, José María A1 - Ranius, Thomas A1 - Thorn, Simon T1 - Salvage logging effects on regulating ecosystem services and fuel loads JF - Frontiers in Ecology and the Environment N2 - Salvage logging, or logging after natural disturbances such as wildfires, insect outbreaks, and windstorms, is carried out to recover some of a forest's natural and/or economic capital. However, trade‐offs between management objectives and a lack of consensus on the ecological consequences of salvage logging impair science‐based decision making on the management of forests after natural disturbances. We conducted a global meta‐analysis of the impacts of salvage logging on regulating ecosystem services and on fuel loads, as a frequent post‐disturbance objective is preventing subsequent wildfires that could be fueled by the accumulation of dead trunks and branches. Salvage logging affected ecosystem services in a moderately negative way, regardless of disturbance type and severity, time elapsed since salvage logging, intensity of salvage logging, and the group of regulating ecosystem services being considered. However, prolonging the time between natural disturbance and salvage logging mitigated negative effects on regulating ecosystem services. Salvage logging had no overall effect on surface fuels; rather, different fuel types responded differently depending on the time elapsed since salvage logging. Delaying salvage logging by ~2–4 years may reduce negative ecological impacts without affecting surface fuel loads. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216111 VL - 18 IS - 7 SP - 391 EP - 400 ER - TY - JOUR A1 - König, Sebastian A1 - Krauss, Jochen A1 - Keller, Alexander A1 - Bofinger, Lukas A1 - Steffan‐Dewenter, Ingolf T1 - Phylogenetic relatedness of food plants reveals highest insect herbivore specialization at intermediate temperatures along a broad climatic gradient JF - Global Change Biology N2 - The composition and richness of herbivore and plant assemblages change along climatic gradients, but knowledge about associated shifts in specialization is scarce and lacks controlling for the abundance and phylogeny of interaction partners. Thus, we aimed to test whether the specialization of phytophagous insects in insect‐plant interaction networks decreases toward cold habitats as predicted by the ‘altitude niche‐breadth hypothesis’ to forecast possible consequences of interaction rewiring under climate change. We used a non‐invasive, standardized metabarcoding approach to reconstruct dietary relationships of Orthoptera species as a major insect herbivore taxon along a broad temperature gradient (~12°C) in Southern Germany. Based on Orthoptera surveys, feeding observations, collection of fecal pellets from >3,000 individuals of 54 species, and parallel vegetation surveys on 41 grassland sites, we quantified plant resource availability and its use by herbivores. Herbivore assemblages were richer in species and individuals at sites with high summer temperatures, while plant richness peaked at intermediate temperatures. Corresponding interaction networks were most specialized in warm habitats. Considering phylogenetic relationships of plant resources, however, the specialization pattern was not linear but peaked at intermediate temperatures, mediated by herbivores feeding on a narrow range of phylogenetically related resources. Our study provides empirical evidence of resource specialization of insect herbivores along a climatic gradient, demonstrating that resource phylogeny, availability, and temperature interactively shape the specialization of herbivore assemblages. Instead of low specialization levels only in cold, harsh habitats, our results suggest increased generalist feeding due to intraspecific changes and compositional differences at both ends of the microclimatic gradient. We conclude that this nonlinear change of phylogeny‐based resource specialization questions predictions derived from the ‘altitude‐niche breadth hypothesis’ and highlights the currently limited understanding of how plant‐herbivore interactions will change under future climatic conditions. KW - Alps KW - diet breadth KW - distance‐based specialization index KW - herbivores KW - interaction networks KW - metabarcoding KW - microclimate KW - Orthoptera KW - plant richness KW - temperature gradient Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-276441 VL - 28 IS - 13 SP - 4027 EP - 4040 ER - TY - JOUR A1 - Sputh, Sebastian A1 - Panzer, Sabine A1 - Stigloher, Christian A1 - Terpitz, Ulrich T1 - Superaufgelöste Mikroskopie: Pilze unter Beobachtung JF - BIOspektrum N2 - The diffraction limit of light confines fluorescence imaging of subcellular structures in fungi. Different super-resolution methods are available for the analysis of fungi that we briefly discuss. We exploit the filamentous fungus Fusarium fujikuroi expressing a YFP-labeled membrane protein showing the benefit of correlative light- and electron microscopy (CLEM), that combines structured illumination microscopy (SIM) and scanning election microscopy (SEM). KW - Pilze KW - mikroskopische Untersuchung KW - Abbe-Limit Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270014 SN - 1868-6249 VL - 27 IS - 4 ER - TY - JOUR A1 - Jarick, Marcel A1 - Bertsche, Ute A1 - Stahl, Mark A1 - Schultz, Daniel A1 - Methling, Karen A1 - Lalk, Michael A1 - Stigloher, Christian A1 - Steger, Mirco A1 - Schlosser, Andreas A1 - Ohlsen, Knut T1 - The serine/threonine kinase Stk and the phosphatase Stp regulate cell wall synthesis in Staphylococcus aureus JF - Scientific Reports N2 - The cell wall synthesis pathway producing peptidoglycan is a highly coordinated and tightly regulated process. Although the major components of bacterial cell walls have been known for decades, the complex regulatory network controlling peptidoglycan synthesis and many details of the cell division machinery are not well understood. The eukaryotic-like serine/threonine kinase Stk and the cognate phosphatase Stp play an important role in cell wall biosynthesis and drug resistance in S. aureus. We show that stp deletion has a pronounced impact on cell wall synthesis. Deletion of stp leads to a thicker cell wall and decreases susceptibility to lysostaphin. Stationary phase Δstp cells accumulate peptidoglycan precursors and incorporate higher amounts of incomplete muropeptides with non-glycine, monoglycine and monoalanine interpeptide bridges into the cell wall. In line with this cell wall phenotype, we demonstrate that the lipid II:glycine glycyltransferase FemX can be phosphorylated by the Ser/Thr kinase Stk in vitro. Mass spectrometric analyses identify Thr32, Thr36 and Ser415 as phosphoacceptors. The cognate phosphatase Stp dephosphorylates these phosphorylation sites. Moreover, Stk interacts with FemA and FemB, but is unable to phosphorylate them. Our data indicate that Stk and Stp modulate cell wall synthesis and cell division at several levels. KW - bacterial transcription KW - pathogens KW - cell wall synthesis Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177333 VL - 8 IS - 13693 ER - TY - JOUR A1 - Gebert, Friederike A1 - Steffan-Dewenter, Ingolf A1 - Moretto, Philippe A1 - Peters, Marcell K. T1 - Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro JF - Journal of Biogeography N2 - Aim: While elevational gradients in species richness constitute some of the best depicted patterns in ecology, there is a large uncertainty concerning the role of food resource availability for the establishment of diversity gradients in insects. Here, we analysed the importance of climate, area, land use and food resources for determining diversity gradients of dung beetles along extensive elevation and land use gradients on Mt. Kilimanjaro, Tanzania. Location: Mt. Kilimanjaro, Tanzania. Taxon: Scarabaeidae (Coleoptera). Methods: Dung beetles were recorded with baited pitfall traps at 66 study plots along a 3.6 km elevational gradient. In order to quantify food resources for the dung beetle community in form of mammal defecation rates, we assessed mammalian diversity and biomass with camera traps. Using a multi‐model inference framework and path analysis, we tested the direct and indirect links between climate, area, land use and mammal defecation rates on the species richness and abundance of dung beetles. Results: We found that the species richness of dung beetles declined exponentially with increasing elevation. Human land use diminished the species richness of functional groups exhibiting complex behaviour but did not have a significant influence on total species richness. Path analysis suggested that climate, in particular temperature and to a lesser degree precipitation, were the most important predictors of dung beetle species richness while mammal defecation rate was not supported as a predictor variable. Main conclusions: Along broad climatic gradients, dung beetle diversity is mainly limited by climatic factors rather than by food resources. Our study points to a predominant role of temperature‐driven processes for the maintenance and origination of species diversity of ectothermic organisms, which will consequently be subject to ongoing climatic changes. KW - altitudinal gradients KW - diversity gradients KW - enercy-richness hypothesis KW - food resources KW - insect abundance KW - land use KW - Scarabaeidae KW - temperature‐richness hypothesis KW - temperature‐mediated resource exploitation hypothesis KW - species‐area hypothesis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204701 VL - 47 IS - 2 SP - 371 EP - 381 ER - TY - JOUR A1 - Requier, Fabrice A1 - Paillet, Yoan A1 - Laroche, Fabienne A1 - Rutschmann, Benjamin A1 - Zhang, Jie A1 - Lombardi, Fabio A1 - Svoboda, Miroslav A1 - Steffan-Dewenter, Ingolf T1 - Contribution of European forests to safeguard wild honeybee populations JF - Conservation Letters N2 - Abstract Recent studies reveal the use of tree cavities by wild honeybee colonies in European forests. This highlights the conservation potential of forests for a highly threatened component of the native entomofauna in Europe, but currently no estimate of potential wild honeybee population sizes exists. Here, we analyzed the tree cavity densities of 106 forest areas across Europe and inferred an expected population size of wild honeybees. Both forest and management types affected the density of tree cavities. Accordingly, we estimated that more than 80,000 wild honeybee colonies could be sustained in European forests. As expected, potential conservation hotspots were identified in unmanaged forests, and, surprisingly, also in other large forest areas across Europe. Our results contribute to the EU policy strategy to halt pollinator declines and reveal the potential of forest areas for the conservation of so far neglected wild honeybee populations in Europe. KW - Apis mellifera KW - Conservation KW - forest management KW - honeybees KW - native populations KW - protected forests KW - tree cavities KW - unmanaged broadleaved forests Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204407 VL - 13 IS - 2 ER - TY - JOUR A1 - Kunz, Tobias C. A1 - Kozjak-Pavlovic, Vera T1 - Diverse facets of sphingolipid involvement in bacterial infections JF - Frontiers in Cell and Developmental Biology N2 - Sphingolipids are constituents of the cell membrane that perform various tasks as structural elements and signaling molecules, in addition to regulating many important cellular processes, such as apoptosis and autophagy. In recent years, it has become increasingly clear that sphingolipids and sphingolipid signaling play a vital role in infection processes. In many cases the attachment and uptake of pathogenic bacteria, as well as bacterial development and survival within the host cell depend on sphingolipids. In addition, sphingolipids can serve as antimicrobials, inhibiting bacterial growth and formation of biofilms. This review will give an overview of our current information about these various aspects of sphingolipid involvement in bacterial infections. KW - infection KW - pathogenic bacteria KW - sphingolipids KW - ceramide KW - autophagy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201757 VL - 7 IS - 203 ER - TY - JOUR A1 - Yang, Tao A1 - Heydarian, Motaharehsadat A1 - Kozjak-Pavlovic, Vera A1 - Urban, Manuela A1 - Harbottle, Richard P. A1 - Rudel, Thomas T1 - Folliculin Controls the Intracellular Survival and Trans-Epithelial Passage of Neisseria gonorrhoeae JF - Frontiers in Cellular and Infection Microbiology N2 - Neisseria gonorrhoeae, a Gram-negative obligate human pathogenic bacterium, infects human epithelial cells and causes sexually transmitted diseases. Emerging multi-antibiotic resistant gonococci and increasing numbers of infections complicate the treatment of infected patients. Here, we used an shRNA library screen and next-generation sequencing to identify factors involved in epithelial cell infection. Folliculin (FLCN), a 64 kDa protein with a tumor repressor function was identified as a novel host factor important for N. gonorrhoeae survival after uptake. We further determined that FLCN did not affect N. gonorrhoeae adherence and invasion but was essential for its survival in the cells by modulating autophagy. In addition, FLCN was also required to maintain cell to cell contacts in the epithelial layer. In an infection model with polarized cells, FLCN inhibited the polarized localization of E-cadherin and the transcytosis of gonococci across polarized epithelial cells. In conclusion, we demonstrate here the connection between FLCN and bacterial infection and in particular the role of FLCN in the intracellular survival and transcytosis of gonococci across polarized epithelial cell layers. KW - gonococcal invasion KW - folliculin KW - autophagy KW - polarized epithelium KW - polarized cell culture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211372 SN - 2235-2988 VL - 10 IS - 422 ER - TY - JOUR A1 - Auer, Daniela A1 - Hügelschäffer, Sophie D. A1 - Fischer, Annette B. A1 - Rudel, Thomas T1 - The chlamydial deubiquitinase Cdu1 supports recruitment of Golgi vesicles to the inclusion JF - Cellular Microbiology N2 - Chlamydia trachomatis is the main cause of sexually transmitted diseases worldwide. As obligate intracellular bacteria Chlamydia replicate in a membrane bound vacuole called inclusion and acquire nutrients for growth and replication from their host cells. However, like all intracellular bacteria, Chlamydia have to prevent eradication by the host's cell autonomous system. The chlamydial deubiquitinase Cdu1 is secreted into the inclusion membrane, facing the host cell cytosol where it deubiquitinates cellular proteins. Here we show that inactivation of Cdu1 causes a growth defect of C. trachomatis in primary cells. Moreover, ubiquitin and several autophagy receptors are recruited to the inclusion membrane of Cdu1‐deficient Chlamydia . Interestingly, the growth defect of cdu1 mutants is not rescued when autophagy is prevented. We find reduced recruitment of Golgi vesicles to the inclusion of Cdu1 mutants indicating that vesicular trafficking is altered in bacteria without active deubiquitinase (DUB). Our work elucidates an important role of Cdu1 in the functional preservation of the chlamydial inclusion surface. KW - autophagy KW - Cdu1 KW - ChlaDUB1 KW - Chlamydia trachomatis KW - DUB KW - Golgi KW - xenophagy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208675 VL - 22 IS - 5 ER - TY - JOUR A1 - Peindl, Matthias A1 - Göttlich, Claudia A1 - Crouch, Samantha A1 - Hoff, Niklas A1 - Lüttgens, Tamara A1 - Schmitt, Franziska A1 - Pereira, Jesús Guillermo Nieves A1 - May, Celina A1 - Schliermann, Anna A1 - Kronenthaler, Corinna A1 - Cheufou, Danjouma A1 - Reu-Hofer, Simone A1 - Rosenwald, Andreas A1 - Weigl, Elena A1 - Walles, Thorsten A1 - Schüler, Julia A1 - Dandekar, Thomas A1 - Nietzer, Sarah A1 - Dandekar, Gudrun T1 - EMT, stemness, and drug resistance in biological context: a 3D tumor tissue/in silico platform for analysis of combinatorial treatment in NSCLC with aggressive KRAS-biomarker signatures JF - Cancers N2 - Epithelial-to-mesenchymal transition (EMT) is discussed to be centrally involved in invasion, stemness, and drug resistance. Experimental models to evaluate this process in its biological complexity are limited. To shed light on EMT impact and test drug response more reliably, we use a lung tumor test system based on a decellularized intestinal matrix showing more in vivo-like proliferation levels and enhanced expression of clinical markers and carcinogenesis-related genes. In our models, we found evidence for a correlation of EMT with drug resistance in primary and secondary resistant cells harboring KRAS\(^{G12C}\) or EGFR mutations, which was simulated in silico based on an optimized signaling network topology. Notably, drug resistance did not correlate with EMT status in KRAS-mutated patient-derived xenograft (PDX) cell lines, and drug efficacy was not affected by EMT induction via TGF-β. To investigate further determinants of drug response, we tested several drugs in combination with a KRAS\(^{G12C}\) inhibitor in KRAS\(^{G12C}\) mutant HCC44 models, which, besides EMT, display mutations in P53, LKB1, KEAP1, and high c-MYC expression. We identified an aurora-kinase A (AURKA) inhibitor as the most promising candidate. In our network, AURKA is a centrally linked hub to EMT, proliferation, apoptosis, LKB1, and c-MYC. This exemplifies our systemic analysis approach for clinical translation of biomarker signatures. KW - EMT KW - drug resistance KW - invasion KW - stemness KW - 3D lung tumor tissue models KW - KRAS biomarker signatures KW - boolean in silico models KW - targeted combination therapy Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270744 SN - 2072-6694 VL - 14 IS - 9 ER - TY - JOUR A1 - Whisnant, Adam W. A1 - Jürges, Christopher S. A1 - Hennig, Thomas A1 - Wyler, Emanuel A1 - Prusty, Bhupesh A1 - Rutkowski, Andrzej J. A1 - L'hernault, Anne A1 - Djakovic, Lara A1 - Göbel, Margarete A1 - Döring, Kristina A1 - Menegatti, Jennifer A1 - Antrobus, Robin A1 - Matheson, Nicholas J. A1 - Künzig, Florian W. H. A1 - Mastrobuoni, Guido A1 - Bielow, Chris A1 - Kempa, Stefan A1 - Liang, Chunguang A1 - Dandekar, Thomas A1 - Zimmer, Ralf A1 - Landthaler, Markus A1 - Grässer, Friedrich A1 - Lehner, Paul J. A1 - Friedel, Caroline C. A1 - Erhard, Florian A1 - Dölken, Lars T1 - Integrative functional genomics decodes herpes simplex virus 1 JF - Nature Communications N2 - The predicted 80 open reading frames (ORFs) of herpes simplex virus 1 (HSV-1) have been intensively studied for decades. Here, we unravel the complete viral transcriptome and translatome during lytic infection with base-pair resolution by computational integration of multi-omics data. We identify a total of 201 transcripts and 284 ORFs including all known and 46 novel large ORFs. This includes a so far unknown ORF in the locus deleted in the FDA-approved oncolytic virus Imlygic. Multiple transcript isoforms expressed from individual gene loci explain translation of the vast majority of ORFs as well as N-terminal extensions (NTEs) and truncations. We show that NTEs with non-canonical start codons govern the subcellular protein localization and packaging of key viral regulators and structural proteins. We extend the current nomenclature to include all viral gene products and provide a genome browser that visualizes all the obtained data from whole genome to single-nucleotide resolution. Here, using computational integration of multi-omics data, the authors provide a detailed transcriptome and translatome of herpes simplex virus 1 (HSV-1), including previously unidentified ORFs and N-terminal extensions. The study also provides a HSV-1 genome browser and should be a valuable resource for further research. KW - infected-cell protein KW - messenger RNA KW - binding protein KW - type 1 KW - identification KW - ICP27 KW - translation KW - expression KW - sequence KW - domain Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229884 VL - 11 ER - TY - JOUR A1 - Habenstein, Jens A1 - Thamm, Markus A1 - Rössler, Wolfgang T1 - Neuropeptides as potential modulators of behavioral transitions in the ant Cataglyphis nodus JF - Journal of Comparative Neurology N2 - Age‐related behavioral plasticity is a major prerequisite for the ecological success of insect societies. Although ecological aspects of behavioral flexibility have been targeted in many studies, the underlying intrinsic mechanisms controlling the diverse changes in behavior along the individual life history of social insects are not completely understood. Recently, the neuropeptides allatostatin‐A, corazonin, and tachykinin have been associated with the regulation of behavioral transitions in social insects. Here, we investigated changes in brain localization and expression of these neuropeptides following major behavioral transitions in Cataglyphis nodus ants. Our immunohistochemical analyses in the brain revealed that the overall branching pattern of neurons immunoreactive (ir) for the three neuropeptides is largely independent of the behavioral stages. Numerous allatostatin‐A‐ and tachykinin‐ir neurons innervate primary sensory neuropils and high‐order integration centers of the brain. In contrast, the number of corazonergic neurons is restricted to only four neurons per brain hemisphere with cell bodies located in the pars lateralis and axons extending to the medial protocerebrum and the retrocerebral complex. Most interestingly, the cell‐body volumes of these neurons are significantly increased in foragers compared to freshly eclosed ants and interior workers. Quantification of mRNA expression levels revealed a stage‐related change in the expression of allatostatin‐A and corazonin mRNA in the brain. Given the presence of the neuropeptides in major control centers of the brain and the neurohemal organs, these mRNA‐changes strongly suggest an important modulatory role of both neuropeptides in the behavioral maturation of Cataglyphis ants. KW - allatostatin‐A KW - corazonin KW - division of labor KW - neuropeptides KW - social insects KW - tachykinin KW - Cataglyphis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244751 VL - 529 IS - 12 SP - 3155 EP - 3170 ER - TY - JOUR A1 - Khayenko, Vladimir A1 - Maric, Hans Michael T1 - Targeting GABA\(_A\)R-associated proteins: new modulators, labels and concepts JF - Frontiers in Molecular Neuroscience N2 - γ-aminobutyric acid type A receptors (GABA\(_A\)Rs) are the major mediators of synaptic inhibition in the brain. Aberrant GABA\(_A\)R activity or regulation is observed in various neurodevelopmental disorders, neurodegenerative diseases and mental illnesses, including epilepsy, Alzheimer’s and schizophrenia. Benzodiazepines, anesthetics and other pharmaceutics targeting these receptors find broad clinical use, but their inherent lack of receptor subtype specificity causes unavoidable side effects, raising a need for new or adjuvant medications. In this review article, we introduce a new strategy to modulate GABAeric signaling: targeting the intracellular protein interactors of GABA\(_A\)Rs. Of special interest are scaffolding, anchoring and supporting proteins that display high GABA\(_A\)R subtype specificity. Recent efforts to target gephyrin, the major intracellular integrator of GABAergic signaling, confirm that GABA\(_A\)R-associated proteins can be successfully targeted through diverse molecules, including recombinant proteins, intrabodies, peptide-based probes and small molecules. Small-molecule artemisinins and peptides derived from endogenous interactors, that specifically target the universal receptor binding site of gephyrin, acutely affect synaptic GABA\(_A\)R numbers and clustering, modifying neuronal transmission. Interference with GABA\(_A\)R trafficking provides another way to modulate inhibitory signaling. Peptides blocking the binding site of GABA\(_A\)R to AP2 increase the surface concentration of GABA\(_A\)R clusters and enhance GABAergic signaling. Engineering of gephyrin binding peptides delivered superior means to interrogate neuronal structure and function. Fluorescent peptides, designed from gephyrin binders, enable live neuronal staining and visualization of gephyrin in the post synaptic sites with submicron resolution. We anticipate that in the future, novel fluorescent probes, with improved size and binding efficiency, may find wide application in super resolution microscopy studies, enlightening the nanoscale architecture of the inhibitory synapse. Broader studies on GABA\(_A\)R accessory proteins and the identification of the exact molecular binding interfaces and affinities will advance the development of novel GABA\(_A\)R modulators and following in vivo studies will reveal their clinical potential as adjuvant or stand-alone drugs. KW - GABAA receptors KW - gephyrin KW - collybistin KW - protein-protein interaction (PPI) KW - super resolution microscopy KW - fluorescent probes KW - dimeric peptide KW - peptide inhibitor design Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201876 VL - 12 IS - 162 ER - TY - JOUR A1 - Habenstein, Jens A1 - Amini, Emad A1 - Grübel, Kornelia A1 - el Jundi, Basil A1 - Rössler, Wolfgang T1 - The brain of Cataglyphis ants: Neuronal organization and visual projections JF - Journal of Comparative Neurology N2 - Cataglyphis ants are known for their outstanding navigational abilities. They return to their inconspicuous nest after far‐reaching foraging trips using path integration, and whenever available, learn and memorize visual features of panoramic sceneries. To achieve this, the ants combine directional visual information from celestial cues and panoramic scenes with distance information from an intrinsic odometer. The largely vision‐based navigation in Cataglyphis requires sophisticated neuronal networks to process the broad repertoire of visual stimuli. Although Cataglyphis ants have been subjected to many neuroethological studies, little is known about the general neuronal organization of their central brain and the visual pathways beyond major circuits. Here, we provide a comprehensive, three‐dimensional neuronal map of synapse‐rich neuropils in the brain of Cataglyphis nodus including major connecting fiber systems. In addition, we examined neuronal tracts underlying the processing of visual information in more detail. This study revealed a total of 33 brain neuropils and 30 neuronal fiber tracts including six distinct tracts between the optic lobes and the cerebrum. We also discuss the importance of comparative studies on insect brain architecture for a profound understanding of neuronal networks and their function. KW - 3D reconstruction KW - ant brain KW - antennal lobes KW - central complex KW - insect KW - mushroom bodies KW - optical tracts Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218212 VL - 528 IS - 18 SP - 3479 EP - 3506 ER - TY - JOUR A1 - Schenk, Mariela A1 - Krauss, Jochen A1 - Holzschuh, Andrea T1 - Desynchronizations in bee-plant interactions cause severe fitness losses in solitary bees JF - Journal of Animal Ecology N2 - 1. Global warming can disrupt mutualistic interactions between solitary bees and plants when increasing temperature differentially changes the timing of interacting partners. One possible scenario is for insect phenology to advance more rapidly than plant phenology. 2. However, empirical evidence for fitness consequences due to temporal mismatches is lacking for pollinators and it remains unknown if bees have developed strategies to mitigate fitness losses following temporal mismatches. 3. We tested the effect of temporal mismatches on the fitness of three spring-emerging solitary bee species, including one pollen specialist. Using flight cages, we simulated (i) a perfect synchronization (from a bee perspective): bees and flowers occur simultaneously, (ii) a mismatch of 3days and (iii) a mismatch of 6days, with bees occurring earlier than flowers in the latter two cases. 4. A mismatch of 6days caused severe fitness losses in all three bee species, as few bees survived without flowers. Females showed strongly reduced activity and reproductive output compared to synchronized bees. Fitness consequences of a 3-day mismatch were species-specific. Both the early-spring species Osmia cornuta and the mid-spring species Osmia bicornis produced the same number of brood cells after a mismatch of 3days as under perfect synchronization. However, O.cornuta decreased the number of female offspring, whereas O.bicornis spread the brood cells over fewer nests, which may increase offspring mortality, e.g. due to parasitoids. The late-spring specialist Osmia brevicornis produced fewer brood cells even after a mismatch of 3days. Additionally, our results suggest that fitness losses after temporal mismatches are higher during warm than cold springs, as the naturally occurring temperature variability revealed that warm temperatures during starvation decreased the survival rate of O.bicornis. 5. We conclude that short temporal mismatches can cause clear fitness losses in solitary bees. Although our results suggest that bees have evolved species-specific strategies to mitigate fitness losses after temporal mismatches, the bees were not able to completely compensate for impacts on their fitness after temporal mismatches with their food resources. KW - conditional sex allocation KW - emergence KW - mitigation strategies KW - mutualism KW - phenological shift KW - pollination KW - species interactions KW - pollinator interactions KW - climate-change KW - phenological response Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228533 VL - 87 IS - 1 ER - TY - JOUR A1 - Boetzl, Fabian A. A1 - Schuele, Maren A1 - Krauss, Jochen A1 - Steffan‐Dewenter, Ingolf T1 - Pest control potential of adjacent agri‐environment schemes varies with crop type and is shaped by landscape context and within‐field position JF - Journal of Applied Ecology N2 - Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri‐environmental schemes (AES) on natural pest control and within‐field distance functions of natural pest control agents have rarely been addressed but might affect the distribution of biocontrol providers. Importantly, it is currently unknown whether ecosystem services provided by adjacent AES are consistent for different crop types during crop rotation. In this study, we assessed whether crop rotation from oilseed rape to cereals altered within‐field distance functions of ground‐dwelling predators from adjacent agri‐environmental fields along a gradient in landscape context. Additionally, we recorded crop pests, predation rates, parasitoids as well as crop yields on a total of 30 study sites. Distance functions varied between trophic levels: Carabid richness decreased while densities of carabid beetles, staphylinid beetles as well as crop yields increased towards the field centres. Distance functions of parasitoids and pests were modulated by the amount of semi‐natural habitat in the surrounding landscape, while the effects of adjacent AES were limited. Distance decay functions found for ground‐dwelling predators in oilseed rape in the previous year were not always present in cereals. Increasing distance to the field edge also increased effects of crop rotation on carabid beetle assemblages, indicating a source habitat function of field edges. Synthesis and applications. Distance functions of natural pest control are not universal and the effects of agri‐environmental schemes (AES) in different adjacent crops during crop rotation vary and depend on ecological contrasts. A network of semi‐natural habitats and spatially optimized AES habitats can benefit pest control in agricultural landscapes, but constraints as a result of crop type need to be addressed by annually targeted, spatially shifting agri‐environment schemes for different crops. KW - cereals KW - distance gradient KW - ecological intensification KW - ecosystem services KW - ground‐dwelling predators KW - parasitoids KW - pest control KW - semi‐natural habitats Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218265 VL - 57 IS - 8 SP - 1482 EP - 1493 ER - TY - JOUR A1 - Heydarian, Motaharehsadat A1 - Schweinlin, Matthias A1 - Schwarz, Thomas A1 - Rawal, Ravisha A1 - Walles, Heike A1 - Metzger, Marco A1 - Rudel, Thomas A1 - Kozjak-Pavlovic, Vera T1 - Triple co-culture and perfusion bioreactor for studying the interaction between Neisseria gonorrhoeae and neutrophils: A novel 3D tissue model for bacterial infection and immunity JF - Journal of Tissue Engineering N2 - Gonorrhea, a sexually transmitted disease caused by the bacteria Neisseria gonorrhoeae, is characterized by a large number of neutrophils recruited to the site of infection. Therefore, proper modeling of the N. gonorrhoeae interaction with neutrophils is very important for investigating and understanding the mechanisms that gonococci use to evade the immune response. We have used a combination of a unique human 3D tissue model together with a dynamic culture system to study neutrophil transmigration to the site of N. gonorrhoeae infection. The triple co-culture model consisted of epithelial cells (T84 human colorectal carcinoma cells), human primary dermal fibroblasts, and human umbilical vein endothelial cells on a biological scaffold (SIS). After the infection of the tissue model with N. gonorrhoeae, we introduced primary human neutrophils to the endothelial side of the model using a perfusion-based bioreactor system. By this approach, we were able to demonstrate the activation and transmigration of neutrophils across the 3D tissue model and their recruitment to the site of infection. In summary, the triple co-culture model supplemented by neutrophils represents a promising tool for investigating N. gonorrhoeae and other bacterial infections and interactions with the innate immunity cells under conditions closely resembling the native tissue environment. KW - Triple co-culture KW - biomimetic 3D tissue model KW - Neisseria gonorrhoeae KW - perfusion-based bioreactor system KW - neutrophil transmigration Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259032 VL - 12 ER - TY - JOUR A1 - Rasa, Santa A1 - Nora-Krukle, Zaiga A1 - Henning, Nina A1 - Eliassen, Eva A1 - Shikova, Evelina A1 - Harrer, Thomas A1 - Scheibenbogen, Carmen A1 - Murovska, Modra A1 - Prusty, Bhupesh K. T1 - Chronic viral infections in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) JF - Journal of Translational Medicine N2 - Background and main text: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and controversial clinical condition without having established causative factors. Increasing numbers of cases during past decade have created awareness among patients as well as healthcare professionals. Chronic viral infection as a cause of ME/CFS has long been debated. However, lack of large studies involving well-designed patient groups and validated experimental set ups have hindered our knowledge about this disease. Moreover, recent developments regarding molecular mechanism of pathogenesis of various infectious agents cast doubts over validity of several of the past studies. Conclusions: This review aims to compile all the studies done so far to investigate various viral agents that could be associated with ME/CFS. Furthermore, we suggest strategies to better design future studies on the role of viral infections in ME/CFS. KW - ME/CFS KW - Viral infections KW - Biomarkers Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224960 VL - 16 IS - 268 ER - TY - JOUR A1 - Jahn, Martin T. A1 - Markert, Sebastian M. A1 - Ryu, Taewoo A1 - Ravasi, Timothy A1 - Stigloher, Christian A1 - Hentschel, Ute A1 - Moitinho-Silva, Lucas T1 - Shedding light on cell compartmentation in the candidate phylum Poribacteria by high resolution visualisation and transcriptional profiling JF - Scientific Reports N2 - Assigning functions to uncultivated environmental microorganisms continues to be a challenging endeavour. Here, we present a new microscopy protocol for fluorescence in situ hybridisation-correlative light and electron microscopy (FISH-CLEM) that enabled, to our knowledge for the first time, the identification of single cells within their complex microenvironment at electron microscopy resolution. Members of the candidate phylum Poribacteria, common and uncultivated symbionts of marine sponges, were used towards this goal. Cellular 3D reconstructions revealed bipolar, spherical granules of low electron density, which likely represent carbon reserves. Poribacterial activity profiles were retrieved from prokaryotic enriched sponge metatranscriptomes using simulation-based optimised mapping. We observed high transcriptional activity for proteins related to bacterial microcompartments (BMC) and we resolved their subcellular localisation by combining FISH-CLEM with immunohistochemistry (IHC) on ultra-thin sponge tissue sections. In terms of functional relevance, we propose that the BMC-A region may be involved in 1,2-propanediol degradation. The FISH-IHC-CLEM approach was proven an effective toolkit to combine -omics approaches with functional studies and it should be widely applicable in environmental microbiology. KW - high resolution visualisation KW - transcriptional profiling KW - FISH-CLEM KW - cell compartmentation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167513 VL - 6 IS - 35860 ER - TY - JOUR A1 - Hagge, Jonas A1 - Müller, Jörg A1 - Birkemoe, Tone A1 - Buse, Jörn A1 - Christensen, Rune Haubo Bojesen A1 - Gossner, Martin M. A1 - Gruppe, Axel A1 - Heibl, Christoph A1 - Jarzabek‐Müller, Andrea A1 - Seibold, Sebastian A1 - Siitonen, Juha A1 - Soutinho, João Gonçalo A1 - Sverdrup‐Thygeson, Anne A1 - Thorn, Simon A1 - Drag, Lukas T1 - What does a threatened saproxylic beetle look like? Modelling extinction risk using a new morphological trait database JF - Journal of Animal Ecology N2 - The extinction of species is a non‐random process, and understanding why some species are more likely to go extinct than others is critical for conservation efforts. Functional trait‐based approaches offer a promising tool to achieve this goal. In forests, deadwood‐dependent (saproxylic) beetles comprise a major part of threatened species, but analyses of their extinction risk have been hindered by the availability of suitable morphological traits. To better understand the mechanisms underlying extinction in insects, we investigated the relationships between morphological features and the extinction risk of saproxylic beetles. Specifically, we hypothesised that species darker in colour, with a larger and rounder body, a lower mobility, lower sensory perception and more robust mandibles are at higher risk. We first developed a protocol for morphological trait measurements and present a database of 37 traits for 1,157 European saproxylic beetle species. Based on 13 selected, independent traits characterising aspects of colour, body shape, locomotion, sensory perception and foraging, we used a proportional‐odds multiple linear mixed‐effects model to model the German Red List categories of 744 species as an ordinal index of extinction risk. Six out of 13 traits correlated significantly with extinction risk. Larger species as well as species with a broad and round body had a higher extinction risk than small, slim and flattened species. Species with short wings had a higher extinction risk than those with long wings. On the contrary, extinction risk increased with decreasing wing load and with higher mandibular aspect ratio (shorter and more robust mandibles). Our study provides new insights into how morphological traits, beyond the widely used body size, determine the extinction risk of saproxylic beetles. Moreover, our approach shows that the morphological characteristics of beetles can be comprehensively represented by a selection of 13 traits. We recommend them as a starting point for functional analyses in the rapidly growing field of ecological and conservation studies of deadwood. KW - deadwood KW - extinction risk KW - forest biodiversity KW - forestry KW - functional traits KW - morphometry KW - red lists KW - saproxylic beetles Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244717 VL - 90 IS - 8 SP - 1934 EP - 1947 ER - TY - THES A1 - Kaya-Zeeb, Sinan David T1 - Octopaminergic Signaling in the Honeybee Flight Muscles : A Requirement for Thermogenesis T1 - Octopaminerge Signalwege in der Flugmuskulatur der Honigbiene : Eine Voraussetzung für die Thermogenese N2 - For all animals the cold represents a dreadful danger. In the event of severe heat loss, animals fall into a chill coma. If this state persists, it is inevitably followed by death. In poikilotherms (e.g. insects), the optimal temperature range is narrow compared to homeotherms (e.g. mammals), resulting in a critical core temperature being reached more quickly. As a consequence, poikilotherms either had to develop survival strategies, migrate or die. Unlike the majority of insects, the Western honeybee (Apis mellifera) is able to organize itself into a superorganism. In this process, worker bees warm and cool the colony by coordinated use of their flight muscles. This enables precise control of the core temperature in the hive, analogous to the core body temperature in homeothermic animals. However, to survive the harsh temperatures in the northern hemisphere, the thermogenic mechanism of honeybees must be in constant readiness. This mechanism is called shivering thermogenesis, in which honeybees generate heat using their flight muscles. My thesis presents the molecular and neurochemical background underlying shivering thermogenesis in worker honeybees. In this context, I investigated biogenic amine signaling. I found that the depletion of vesicular monoamines impairs thermogenesis, resulting in a decrease in thoracic temperature. Subsequent investigations involving various biogenic amines showed that octopamine can reverse this effect. This clearly indicates the involvement of the octopaminergic system. Proceeding from these results, the next step was to elucidate the honeybee thoracic octopaminergic system. This required a multidisciplinary approach to ultimately provide profound insights into the function and action of octopamine at the flight muscles. This led to the identification of octopaminergic flight muscle controlling neurons, which presumably transport octopamine to the flight muscle release sites. These neurons most likely innervate octopamine β receptors and their activation may stimulate intracellular glycolytic pathways, which ensure sufficient energy supply to the muscles. Next, I examined the response of the thoracic octopaminergic system to cold stress conditions. I found that the thoracic octopaminergic system tends towards an equilibrium, even though the initial stress response leads to fluctuations of octopamine signaling. My results indicate the importance of the neuro-muscular octopaminergic system and thus the need for its robustness. Moreover, cold sensitivity was observed for the expression of one transcript of the octopamine receptor gene AmOARβ2. Furthermore, I found that honeybees without colony context show a physiological disruption within the octopaminergic system. This disruption has profound effects on the honeybees protection against the cold. I could show how important the neuro-muscular octopaminergic system is for thermogenesis in honeybees. In this context, the previously unknown neurochemical modulation of the honeybee thorax has now been revealed. I also provide a broad basis to conduct further experiments regarding honeybee thermogenesis and muscle physiology. N2 - Kälte stellt für alle Tiere eine lebensbedrohliche Situation dar. Erleiden sie einen schwerwiegenden Wärmeverlust, stellt sich der Zustand eines Kältekomas ein. Hält dieser Zustand über einen längeren Zeitraum an, folgt unweigerlich der Tod. Poikilotherme (z.B. Insekten) weisen ein schmaleres optimales Temperaturfenster als Homoiotherme (z.B. Säugetiere) auf, wodurch sie ihre kritische Körpertemperatur schneller erreichen. Dadurch waren Poikilotherme gezwungen entweder Überlebenstrategien zu entwickeln, abzuwandern oder zu sterben. Im Gegensatz zu den meisten anderen Insektenarten, ist die Westliche Honigbiene Apis mellifera in der Lage einen Superorganismus zu bilden, in dem Arbeiterbienen durch den koordinierten Einsatz ihrer Flugmuskeln für Erwärmung oder Abkühlung sorgen. In Analogie zur Körpertemperatur von Homoiothermen, ermöglicht dies die exakte Kontrolle der Kerntemperatur des Bienenstocks. Um unter den rauen Bedingungen in der nördlichen Hemisphäre bestehen zu können, muss eine ununterbrochene Einsatzbereitschaft des thermogenen Mechanismus der Honigbiene garantiert werden. Dabei ist die Honigbiene in der Lage durch Zittern der Flugmuskulatur Wärme zu erzeugen. In dieser Dissertation stelle ich die molekularen und neurochemischen Grundlagen des thermogenen Muskelzitterns bei Honigbienenarbeiterinnen vor. In diesem Zusammenhang habe ich die Signalwege von verschiedenen biogenen Aminen untersucht und konnte demonstrieren, dass eine Erschöpfung vesikulärer Monoamine den Prozess der Thermogenese beeinflusst und zu einem Absinken der Thoraxtemperatur führt. Unter Einbeziehung veschiedener biogener Amine, konnten Folgeuntersuchungen zeigen, dass dieser Effekt durch Octopamin rückgängig gemacht werden kann. Dies weist eindeutig auf eine Beteiligung des octopaminergen Systems hin. Auf Basis dieser Erkenntnisse folgte die Erforschung des thorakalen octopaminergen Systems der Honigbiene. Dabei erforderte es einen multidisziplinären Ansatz, um weitere Einblicke in die Funktion und Wirkung von Octopamin in der Flugmuskulatur zu gewinnen. Im Zuge dessen, konnten flugmuskelinnervierende octopaminerge Neuronen identifiziert werden, die mutmaßlich die Flugmuskeln mit Octopamin versorgen. Es sind höchstwahrscheinlich diese Neuronen, die für eine Stimulation von Octopamin-β-Rezeptoren verantwortlich sind und wordurch intrazelluläre glykolytische Prozesse eine ausreichende Muskelversorgung gewährleisten. In den darauffolgenden Experimenten habe ich das Ansprechen des thorakalen octopaminergen Systems auf Kältestress untersucht und konnte zeigen, dass dieses System nach einem Gleichgewichtszustand strebt. Dies trifft selbst nach einer starken initialen Stressantwort zu. Meine Ergebnisse verdeutlichen die Bedeutsamkeit des neuromuskulären octopaminergen Systems und zeigen seine erforderliche Resilienz gegenüber exogenen Faktoren. Es konnte die Kälteempfindlichkeit eines Transkriptes des Octopaminrezeptorgens AmOARβ2 nachgewiesen werden. Zusätzlich konnte ich zeigen, dass Honigbienen ohne den sozialen Kontext der Kolonie eine starke physiologische Störung innerhalb des untersuchten Systems und damit auch in Bezug auf ihre Kälteresilienz aufweisen. Meine Dissertation verdeutlicht die enorme Bedeutung des neuromuskulären octopaminergen Systems im Kontext der Thermogenese im Organismus Honigbiene. In diesem Rahmen konnte die bisher unerforschte neurochemische Modulation des Honigbienenthorax aufgeklärt werden. Darüber hinaus bietet meine Arbeit eine Grundlage für künftige Experimente zur Thermogenese und Muskelphysiologie der Honigbiene. KW - Octopamin KW - Biene KW - Octopamine KW - Thermogenesis KW - Honeybee KW - Octopaminergic signaling KW - Flight muscle Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-314089 ER - TY - THES A1 - Geis, Maria T1 - Identifizierung von Zielmolekülen und Herstellung zweigeteilter trivalenter T-Zell-aktivierender Antikörperderivate zur immuntherapeutischen Behandlung von Multiplen Myelom T1 - Target identification and generation of trivalent T-cell activating antibody derivatives for multiple myeloma immunotherapy N2 - T-Zell-aktivierende Formate, wie BiTE (bispecific T-cell engagers) Antikörper und CAR T Zellen haben in den vergangen Jahren die Therapiemöglichkeiten für Tumorpatienten erweitert. Diese Therapeutika verknüpfen T-Zellen mit malignen Zellen über je ein spezifisches Oberflächenmolekül und initiieren, über eine T-Zell-vermittelte Immunantwort, die Lyse der Tumorzelle. Tumorspezifische Antigene sind jedoch selten. Häufig werden Proteine adressiert, die neben den Tumorzellen auch auf gesunden Zellen exprimiert werden. Die Folgen sind toxische Effekte abseits der Tumorzellen auf Antigen-positiven gesunden Zellen (on target/off tumor), welche nicht nur die Dosis des Therapeutikums und dessen Effektivität limitieren, sondern zu geringen bis letalen Begleiterscheinungen führen können. Der Bedarf an effektiven Therapieformen mit geringen Nebenwirkungen ist folglich immer noch sehr hoch. Diese Lücke soll durch ein neues Antikörperformat, sogenannten Hemibodies, geschlossen werden. Hemibodies sind eine neue Klasse von T-Zell-aktivierenden Antikörpern, die sich gegen eine Antigenkombination und nicht einzelne Antigene auf Tumorzellen richten. Sie bestehen aus zwei komplementären Molekülen mit je einer Antigen-bindenden Sequenz, die entweder mit der leichten (VL) oder der schweren (VH) Kette eines T-Zell-aktivierenden anti CD3 Antikörpers fusioniert ist. Nur wenn beide Hemibody-Fragmente gleichzeitig in unmittelbarer Nähe an ihr jeweiliges Antigenepitop auf der Tumorzelle binden, komplementieren die beiden Antikörperkonstrukte über das geteilte anti-CD3 und bilden einen trivalenten T Zell aktivierenden Komplex aus. Diese funktionale Einheit rekrutiert T-Zellen zur Tumorzelle und induzierte die T-Zell-vermittelte Lyse der malignen Zelle. Im Rahmen der vorliegenden Arbeit wurden geeignete Antigenkombinationen identifiziert und die erste effektive und spezifische Hemibody-basierte Immuntherapie gegen das Multiple Myelom (MM), ohne Nebenwirkungen auf Antigen-einfach-positiven gesunden Zellen, entwickelt. Basierend auf einer umfangreichen Analyse von Kandidaten-Antigenen wurden Kombinationen aus bekannten MM Zielmolekülen, wie BCMA, CD38, CD138, CD229 und SLAMF7, und für das MM unbekannte Oberflächenmolekülen, wie CHRM5 und LAX1, untersucht. Gegen die vielversprechendsten Antigene wurden Hemibodies entwickelt und produziert. Im Zusammenhang mit Analysen zur Produzierbarkeit sowie biochemischen und funktionalen Charakterisierungen, konnte aus 75 initialen Hemibody-Kombinationen drei Kombinationen mit geeigneten Eigenschaften identifiziert werden. Die Bindung von zwei Hemibody-Partnern auf der Oberfläche der MM Zelle führte zur Ausbildung eines trivalenten T-Zell-rekrutierenden Komplexes. Dieser initiierte nachfolgend über eine T-Zell-vermittelte Immunantwort die spezifische Lyse der malignen Zellen, ohne die Viabilität von Antigen-einfach-positiven gesunden Körper- oder Effektor-Zellen zu beeinflussen. Zusätzlich führte eine Hemibody-Therapie in vivo in einem NOD SCID MM-Mausmodel innerhalb von 7 Tagen zur kompletten Remission der MM Zellen. Diese Daten zeigten Hemibodies als ein neues, sehr vielversprechendes Antikörperformat für eine effektive und tumorspezifische Immuntherapie mit potentiell geringen Nebenwirkungen. N2 - T-cell activating therapies such as BiTEs (bispecific T-cell engagers) and CAR-T-cells have broadened the treatment options for cancer patients in the past years. These therapeutics induce a T-cell mediated immune response by linking T-cells with malignant cells by a specific target on the tumor cell. Tumor-specific antigens are rare and often antigens expressed on malignant and healthy tissues are addressed. Consequently, dosage and efficacy are limited by on-target/off-tumor toxicities, which can cause severe side effects. Efficient therapies with no side effects are still needed. To overcome these limitations and fill the gap of existing cancer immunotherapies, our novel strategy, coined hemibodies, targets an aberrant antigen signature uniquely expressed on tumor cells. Hemibodies are a new class of T-cell engaging antibodies consisting of two complementing molecules. Each hemibody molecule can bind one specific target on a tumor cell using a scFv fused to either the variable heavy (VH) or light (VL) chain domain of a T-cell activating anti-CD3 antibody. When both hemibodies simultaneously bind their specific target, the VL- and the VH-domain reconstitute and form a functional anti-CD3 domain, enabling T-cell recruitment for tumor cell lysis. This way, hemibodies form a trivalent protein complex only on tumor cells for safe cancer immunotherapy. The following work presents target combinations and the first hemibody-based immunotherapy for a precise multiple myeloma (MM) treatment, without side effects, on target-single-positiv cells. Besides combinations of known and often reported MM targets like CD138, CD38, BCMA and SLAMF7, new targets including CHRM5 and LAX1 are described. Moreover, three hemibody combinations out of 75 promising target combinations were identified that displayed favorable production and purification data as well as biochemical and functional characteristics. We demonstrated that hemibodies are able to recognize and bind MM cells on their specific targets and form a functional trivalent T-cell activating complex for tumor cell lysis. In contrast to BiTE antibodies, hemibody-fragments alone and in combination had no/low effects on the viability of target-single positive cells or on T-cells in the absence of tumor cells. Only in the presence of MM cells, hemibodies recruit T-cells to the tumor site and induce tumor specific lysis. In addition, human T-lymphocytes rejected MM cells after treatment with a hemibody combination for seven days in a murine NOD SCID model. In aggregate, the data reported here identified hemibodies as a promising therapeutic protein format for effective and safe cancer immunotherapy. KW - zweigeteilte trivalente T-Zell-aktivierende Antikörperderivate KW - Hemibodies Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186906 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 - Grittner, Rebecca A1 - Baird, Emily A1 - Stöckl, Anna T1 - Spatial tuning of translational optic flow responses in hawkmoths of varying body size JF - Journal of Comparative Physiology A N2 - To safely navigate their environment, flying insects rely on visual cues, such as optic flow. Which cues insects can extract from their environment depends closely on the spatial and temporal response properties of their visual system. These in turn can vary between individuals that differ in body size. How optic flow-based flight control depends on the spatial structure of visual cues, and how this relationship scales with body size, has previously been investigated in insects with apposition compound eyes. Here, we characterised the visual flight control response limits and their relationship to body size in an insect with superposition compound eyes: the hummingbird hawkmoth Macroglossum stellatarum. We used the hawkmoths' centring response in a flight tunnel as a readout for their reception of translational optic flow stimuli of different spatial frequencies. We show that their responses cut off at different spatial frequencies when translational optic flow was presented on either one, or both tunnel walls. Combined with differences in flight speed, this suggests that their flight control was primarily limited by their temporal rather than spatial resolution. We also observed strong individual differences in flight performance, but no correlation between the spatial response cutoffs and body or eye size. KW - allometry KW - vision KW - optic flow KW - flight control KW - hawkmoth Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-266565 SN - 1432-1351 VL - 208 IS - 2 ER - TY - JOUR A1 - Al-Warhi, Tarfah A1 - Elmaidomy, Abeer H. A1 - Maher, Sherif A. A1 - Abu-Baih, Dalia H. A1 - Selim, Samy A1 - Albqmi, Mha A1 - Al-Sanea, Mohammad M. A1 - Alnusaire, Taghreed S. A1 - Ghoneim, Mohammed M. A1 - Mostafa, Ehab M. A1 - Hussein, Shaimaa A1 - El-Damasy, Ashraf K. A1 - Saber, Entesar Ali A1 - Elrehany, Mahmoud A. A1 - Sayed, Ahmed M. A1 - Othman, Eman M. A1 - El-Sherbiny, Mohamed A1 - Abdelmohsen, Usama Ramadan T1 - The wound-healing potential of Olea europaea L. Cv. Arbequina leaves extract: an integrated in vitro, in silico, and in vivo investigation JF - Metabolites N2 - Olea europaea L. Cv. Arbequina (OEA) (Oleaceae) is an olive variety species that has received little attention. Besides our previous work for the chemical profiling of OEA leaves using LC–HRESIMS, an additional 23 compounds are identified. An excision wound model is used to measure wound healing action. Wounds are provided with OEA (2% w/v) or MEBO\(^®\) cream (marketed treatment). The wound closure rate related to vehicle-treated wounds is significantly increased by OEA. Comparing to vehicle wound tissues, significant levels of TGF-β in OEA and MEBO\(^®\) (p < 0.05) are displayed by gene expression patterns, with the most significant levels in OEA-treated wounds. Proinflammatory TNF-α and IL-1β levels are substantially reduced in OEA-treated wounds. The capability of several lignan-related compounds to interact with MMP-1 is revealed by extensive in silico investigation of the major OEA compounds (i.e., inverse docking, molecular dynamics simulation, and ΔG calculation), and their role in the wound-healing process is also characterized. The potential of OEA as a potent MMP-1 inhibitor is shown in subsequent in vitro testing (IC\(_{50}\) = 88.0 ± 0.1 nM). In conclusion, OEA is introduced as an interesting therapeutic candidate that can effectively manage wound healing because of its anti-inflammatory and antioxidant properties. KW - olive KW - LC–HRESIMS KW - wound KW - Olea KW - TNF-α KW - virtual docking KW - TGF-β KW - MMP-1 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286150 SN - 2218-1989 VL - 12 IS - 9 ER - TY - JOUR A1 - Lapuente, Juan A1 - Arandjelovic, Mimi A1 - Kühl, Hjalmar A1 - Dieguez, Paula A1 - Boesch, Christophe A1 - Linsenmair, K. Eduard T1 - Sustainable Peeling of Kapok Tree (Ceiba pentandra) Bark by the Chimpanzees (Pan troglodytes verus) of Comoé National Park, Ivory Coast JF - International Journal of Primatology N2 - Primates often consume either bark or cambium (inner bark) as a fallback food tocomplete their diet during periods of food scarcity. Wild chimpanzees exhibit greatbehavioral diversity across Africa, as studies of new populations frequently reveal.Since 2014, we have been using a combination of camera traps and indirect signs tostudy the ecology and behavior of wild chimpanzees (Pan troglodytes verus) in ComoéNational Park, Ivory Coast, to document and understand the behavioral adaptations thathelp them to survive in a savanna–forest mosaic landscape. We found that Comoéchimpanzees peel the bark of the buttresses of kapok tree (Ceiba pentandra) trees to eatthe cambium underneath. Individuals of all sex/age classes across at least six neigh-boring communities peeled the bark, but only during the late rainy season andbeginning of the dry season, when cambium may represent an important fallback food.Baboons (Papio anubis) also target the same trees but mainly eat the bark itself. Mostof the bark-peeling wounds onCeibatrees healed completely within 2 years, seeminglywithout any permanent damage. We recorded chimpanzees visiting trees in early stagesof wound recovery but leaving them unpeeled. Only 6% of peeled trees (N= 53) werereexploited after a year, suggesting that chimpanzees waited for the rest of the trees toregrow the bark fully before peeling them again, thus using them sustainably. Manyhuman groups of hunter-gatherers and herders exploited cambium sustainably in thepast. The observation that similar sustainable bark-peeling behavior evolved in bothchimpanzees and humans suggests that it has an important adaptive value in harshenvironments when other food sources become seasonally scarce, by avoiding thedepletion of the resource and keeping it available for periods of scarcity. KW - bark-peeling KW - ceiba pentandra KW - chimpanzee KW - Savanna–Forest mosaic KW - sustainable Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232581 SN - 0164-0291 VL - 41 ER - TY - JOUR A1 - Vogel, Cassandra A1 - Chunga, Timothy L. A1 - Sun, Xiaoxuan A1 - Poveda, Katja A1 - Steffan-Dewenter, Ingolf T1 - Higher bee abundance, but not pest abundance, in landscapes with more agriculture on a late-flowering legume crop in tropical smallholder farms JF - PeerJ N2 - Background Landscape composition is known to affect both beneficial insect and pest communities on crop fields. Landscape composition therefore can impact ecosystem (dis)services provided by insects to crops. Though landscape effects on ecosystem service providers have been studied in large-scale agriculture in temperate regions, there is a lack of representation of tropical smallholder agriculture within this field of study, especially in sub-Sahara Africa. Legume crops can provide important food security and soil improvement benefits to vulnerable agriculturalists. However, legumes are dependent on pollinating insects, particularly bees (Hymenoptera: Apiformes) for production and are vulnerable to pests. We selected 10 pigeon pea (Fabaceae: Cajunus cajan (L.)) fields in Malawi with varying proportions of semi-natural habitat and agricultural area within a 1 km radius to study: (1) how the proportion of semi-natural habitat and agricultural area affects the abundance and richness of bees and abundance of florivorous blister beetles (Coleoptera: Melloidae), (2) if the proportion of flowers damaged and fruit set difference between open and bagged flowers are correlated with the proportion of semi-natural habitat or agricultural area and (3) if pigeon pea fruit set difference between open and bagged flowers in these landscapes was constrained by pest damage or improved by bee visitation. Methods We performed three, ten-minute, 15 m, transects per field to assess blister beetle abundance and bee abundance and richness. Bees were captured and identified to (morpho)species. We assessed the proportion of flowers damaged by beetles during the flowering period. We performed a pollinator and pest exclusion experiment on 15 plants per field to assess whether fruit set was pollinator limited or constrained by pests. Results In our study, bee abundance was higher in areas with proportionally more agricultural area surrounding the fields. This effect was mostly driven by an increase in honeybees. Bee richness and beetle abundances were not affected by landscape characteristics, nor was flower damage or fruit set difference between bagged and open flowers. We did not observe a positive effect of bee density or richness, nor a negative effect of florivory, on fruit set difference. Discussion In our study area, pigeon pea flowers relatively late—well into the dry season. This could explain why we observe higher densities of bees in areas dominated by agriculture rather than in areas with more semi-natural habitat where resources for bees during this time of the year are scarce. Therefore, late flowering legumes may be an important food resource for bees during a period of scarcity in the seasonal tropics. The differences in patterns between our study and those conducted in temperate regions highlight the need for landscape-scale studies in areas outside the temperate region. KW - Pollination KW - Small-holder agriculture KW - Legume crops KW - Insect pests KW - Tropical agriculture KW - Landscape ecology KW - Plant-insect interactions KW - African agriculture KW - Ecosystem services KW - Agro-ecology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231491 VL - 9 ER - TY - JOUR A1 - Eder, Sascha A1 - Hollmann, Claudia A1 - Mandasari, Putri A1 - Wittmann, Pia A1 - Schumacher, Fabian A1 - Kleuser, Burkhard A1 - Fink, Julian A1 - Seibel, Jürgen A1 - Schneider-Schaulies, Jürgen A1 - Stigloher, Christian A1 - Beyersdorf, Niklas A1 - Dembski, Sofia T1 - Synthesis and characterization of ceramide-containing liposomes as membrane models for different T cell subpopulations JF - Journal of Functional Biomaterials N2 - A fine balance of regulatory (T\(_{reg}\)) and conventional CD4\(^+\) T cells (T\(_{conv}\)) is required to prevent harmful immune responses, while at the same time ensuring the development of protective immunity against pathogens. As for many cellular processes, sphingolipid metabolism also crucially modulates the T\(_{reg}\)/T\(_{conv}\) balance. However, our understanding of how sphingolipid metabolism is involved in T cell biology is still evolving and a better characterization of the tools at hand is required to advance the field. Therefore, we established a reductionist liposomal membrane model system to imitate the plasma membrane of mouse T\(_{reg}\) and T\(_{conv}\) with regards to their ceramide content. We found that the capacity of membranes to incorporate externally added azide-functionalized ceramide positively correlated with the ceramide content of the liposomes. Moreover, we studied the impact of the different liposomal preparations on primary mouse splenocytes in vitro. The addition of liposomes to resting, but not activated, splenocytes maintained viability with liposomes containing high amounts of C\(_{16}\)-ceramide being most efficient. Our data thus suggest that differences in ceramide post-incorporation into T\(_{reg}\) and T\(_{conv}\) reflect differences in the ceramide content of cellular membranes. KW - liposome KW - ceramide KW - cell membrane model Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286130 SN - 2079-4983 VL - 13 IS - 3 ER - TY - JOUR A1 - Nazzal, Yousef A1 - Howari, Fares M. A1 - Yaslam, Aya A1 - Iqbal, Jibran A1 - Maloukh, Lina A1 - Ambika, Lakshmi Kesari A1 - Al-Taani, Ahmed A. A1 - Ali, Ijaz A1 - Othman, Eman M. A1 - Jamal, Arshad A1 - Naseem, Muhammad T1 - A methodological review of tools that assess dust microbiomes, metatranscriptomes and the particulate chemistry of indoor dust JF - Atmosphere N2 - Indoor house dust is a blend of organic and inorganic materials, upon which diverse microbial communities such as viruses, bacteria and fungi reside. Adequate moisture in the indoor environment helps microbial communities multiply fast. The outdoor air and materials that are brought into the buildings by airflow, sandstorms, animals pets and house occupants endow the indoor dust particles with extra features that impact human health. Assessment of the health effects of indoor dust particles, the type of indoor microbial inoculants and the secreted enzymes by indoor insects as allergens merit detailed investigation. Here, we discuss the applications of next generation sequencing (NGS) technology which is used to assess microbial diversity and abundance of the indoor dust environments. Likewise, the applications of NGS are discussed to monitor the gene expression profiles of indoor human occupants or their surrogate cellular models when exposed to aqueous solution of collected indoor dust samples. We also highlight the detection methods of dust allergens and analytical procedures that quantify the chemical nature of indoor particulate matter with a potential impact on human health. Our review is thus unique in advocating the applications of interdisciplinary approaches that comprehensively assess the health effects due to bad air quality in built environments. KW - indoor dust KW - allergens KW - metagenomics KW - particulate matter KW - microbiomes KW - transcriptomes KW - health effects Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285957 SN - 2073-4433 VL - 13 IS - 8 ER - TY - JOUR A1 - Sarukhanyan, Edita A1 - Shanmugam, Tipack Ayothyapattanam A1 - Dandekar, Thomas T1 - In silico studies reveal Peramivir and Zanamivir as an optimal drug treatment even if H7N9 avian type influenza virus acquires further resistance JF - Molecules N2 - An epidemic of avian type H7N9 influenza virus, which took place in China in 2013, was enhanced by a naturally occurring R294K mutation resistant against Oseltamivir at the catalytic site of the neuraminidase. To cope with such drug-resistant neuraminidase mutations, we applied the molecular docking technique to evaluate the fitness of the available drugs such as Oseltamivir, Zanamivir, Peramivir, Laninamivir, L-Arginine and Benserazide hydrochloride concerning the N9 enzyme with single (R294K, R119K, R372K), double (R119_294K, R119_372K, R294_372K) and triple (R119_294_372K) mutations in the pocket. We found that the drugs Peramivir and Zanamivir score best amongst the studied compounds, demonstrating their high binding potential towards the pockets with the considered mutations. Despite the fact that mutations changed the shape of the pocket and reduced the binding strength for all drugs, Peramivir was the only drug that formed interactions with the key residues at positions 119, 294 and 372 in the pocket of the triple N9 mutant, while Zanamivir demonstrated the lowest RMSD value (0.7 Å) with respect to the reference structure. KW - H7N9 influenza virus KW - neuraminidase KW - mutation KW - binding pocket KW - molecular docking Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288240 SN - 1420-3049 VL - 27 IS - 18 ER - TY - JOUR A1 - Gupta, Shishir K. A1 - Minocha, Rashmi A1 - Thapa, Prithivi Jung A1 - Srivastava, Mugdha A1 - Dandekar, Thomas T1 - Role of the pangolin in origin of SARS-CoV-2: an evolutionary perspective JF - International Journal of Molecular Sciences N2 - After the recent emergence of SARS-CoV-2 infection, unanswered questions remain related to its evolutionary history, path of transmission or divergence and role of recombination. There is emerging evidence on amino acid substitutions occurring in key residues of the receptor-binding domain of the spike glycoprotein in coronavirus isolates from bat and pangolins. In this article, we summarize our current knowledge on the origin of SARS-CoV-2. We also analyze the host ACE2-interacting residues of the receptor-binding domain of spike glycoprotein in SARS-CoV-2 isolates from bats, and compare it to pangolin SARS-CoV-2 isolates collected from Guangdong province (GD Pangolin-CoV) and Guangxi autonomous regions (GX Pangolin-CoV) of South China. Based on our comparative analysis, we support the view that the Guangdong Pangolins are the intermediate hosts that adapted the SARS-CoV-2 and represented a significant evolutionary link in the path of transmission of SARS-CoV-2 virus. We also discuss the role of intermediate hosts in the origin of Omicron. KW - COVID-19 KW - SARS-CoV-2 KW - origin KW - evolution KW - intermediate host KW - pangolin KW - mutation KW - recombination KW - adaptation KW - transmission KW - comparative sequence analysis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285995 SN - 1422-0067 VL - 23 IS - 16 ER - TY - JOUR A1 - Dhillon, Maninder Singh A1 - Dahms, Thorsten A1 - Kübert-Flock, Carina A1 - Steffan-Dewenter, Ingolf A1 - Zhang, Jie A1 - Ullmann, Tobias T1 - Spatiotemporal Fusion Modelling Using STARFM: Examples of Landsat 8 and Sentinel-2 NDVI in Bavaria JF - Remote Sensing N2 - The increasing availability and variety of global satellite products provide a new level of data with different spatial, temporal, and spectral resolutions; however, identifying the most suited resolution for a specific application consumes increasingly more time and computation effort. The region’s cloud coverage additionally influences the choice of the best trade-off between spatial and temporal resolution, and different pixel sizes of remote sensing (RS) data may hinder the accurate monitoring of different land cover (LC) classes such as agriculture, forest, grassland, water, urban, and natural-seminatural. To investigate the importance of RS data for these LC classes, the present study fuses NDVIs of two high spatial resolution data (high pair) (Landsat (30 m, 16 days; L) and Sentinel-2 (10 m, 5–6 days; S), with four low spatial resolution data (low pair) (MOD13Q1 (250 m, 16 days), MCD43A4 (500 m, one day), MOD09GQ (250 m, one-day), and MOD09Q1 (250 m, eight day)) using the spatial and temporal adaptive reflectance fusion model (STARFM), which fills regions’ cloud or shadow gaps without losing spatial information. These eight synthetic NDVI STARFM products (2: high pair multiply 4: low pair) offer a spatial resolution of 10 or 30 m and temporal resolution of 1, 8, or 16 days for the entire state of Bavaria (Germany) in 2019. Due to their higher revisit frequency and more cloud and shadow-free scenes (S = 13, L = 9), Sentinel-2 (overall R\(^2\) = 0.71, and RMSE = 0.11) synthetic NDVI products provide more accurate results than Landsat (overall R\(^2\) = 0.61, and RMSE = 0.13). Likewise, for the agriculture class, synthetic products obtained using Sentinel-2 resulted in higher accuracy than Landsat except for L-MOD13Q1 (R\(^2\) = 0.62, RMSE = 0.11), resulting in similar accuracy preciseness as S-MOD13Q1 (R\(^2\) = 0.68, RMSE = 0.13). Similarly, comparing L-MOD13Q1 (R\(^2\) = 0.60, RMSE = 0.05) and S-MOD13Q1 (R\(^2\) = 0.52, RMSE = 0.09) for the forest class, the former resulted in higher accuracy and precision than the latter. Conclusively, both L-MOD13Q1 and S-MOD13Q1 are suitable for agricultural and forest monitoring; however, the spatial resolution of 30 m and low storage capacity makes L-MOD13Q1 more prominent and faster than that of S-MOD13Q1 with the 10-m spatial resolution. KW - Landsat KW - Sentinel-2 KW - NDVI KW - fusion KW - agriculture KW - grassland KW - forest KW - urban KW - water Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323471 SN - 2072-4292 VL - 14 IS - 3 ER - TY - THES A1 - Schilcher, Felix T1 - Regulation of the nurse-forager transition in honeybees (\(Apis\) \(mellifera\)) T1 - Regulation des Ammen–Sammlerinnen-Übergangs in Honigbienen (\(Apis\) \(mellifera\)) N2 - Honeybees are among the few animals that rely on eusociality to survive. While the task of queen and drones is only reproduction, all other tasks are accomplished by sterile female worker bees. Different tasks are mostly divided by worker bees of different ages (temporal polyethism). Young honeybees perform tasks inside the hive like cleaning and nursing. Older honeybees work at the periphery of the nest and fulfill tasks like guarding the hive entrance. The oldest honeybees eventually leave the hive to forage for resources until they die. However, uncontrollable circumstances might force the colony to adapt or perish. For example, the introduced Varroa destructor mite or the deformed wing virus might erase a lot of in-hive bees. On the other hand, environmental events might kill a lot of foragers, leaving the colony with no new food intake. Therefore, adaptability of task allocation must be a priority for a honeybee colony. In my dissertation, I employed a wide range of behavioral, molecular biological and analytical techniques to unravel the underlying molecular and physiological mechanisms of the honeybee division of labor, especially in conjunction with honeybee malnourishment. The genes AmOARα1, AmTAR1, Amfor and vitellogenin have long been implied to be important for the transition from in-hive tasks to foraging. I have studied in detail expression of all of these genes during the transition from nursing to foraging to understand how their expression patterns change during this important phase of life. My focus lay on gene expression in the honeybee brain and fat body. I found an increase in the AmOARα1 and the Amforα mRNA expression with the transition from in-hive tasks to foraging and a decrease in expression of the other genes in both tissues. Interestingly, I found the opposite pattern of the AmOARα1 and AmTAR1 mRNA expression in the honeybee fat body during orientation flights. Furthermore, I closely observed juvenile hormone titers and triglyceride levels during this crucial time. Juvenile hormone titers increased with the transition from in-hive tasks to foraging and triglyceride levels decreased. Furthermore, in-hive bees and foragers also differ on a behavioral and physiological level. For example, foragers are more responsive towards light and sucrose. I proposed that modulation via biogenic amines, especially via octopamine and tyramine, can increase or decrease the responsiveness of honeybees. For that purpose, in-hive bees and foragers were injected with both biogenic amines and the receptor response was quantified 1 using electroretinography. In addition, I studied the behavioral response of the bees to light using a phototaxis assay. Injecting octopamine increased the receptor response and tyramine decreased it. Also, both groups of honeybees showed an increased phototactic response when injected with octopamine and a decreased response when injected with tyramine, independent of locomotion. Additionally, nutrition has long been implied to be a driver for division of labor. Undernourished honeybees are known to speed up their transition to foragers, possibly to cope with the missing resources. Furthermore, larval undernourishment has also been implied to speed up the transition from in-hive bees to foragers, due to increasing levels of juvenile hormone titers in adult honeybees after larval starvation. Therefore, I reared honeybees in-vitro to compare the hatched adult bees of starved and overfed larvae to bees reared under the standard in-vitro rearing diet. However, first I had to investigate whether the in-vitro rearing method affects adult honeybees. I showed effects of in-vitro rearing on behavior, with in-vitro reared honeybees foraging earlier and for a shorter time than hive reared honeybees. Yet, nursing behavior was unaffected. Afterwards, I investigated the effects of different larval diets on adult honeybee workers. I found no effects of malnourishment on behavioral or physiological factors besides a difference in weight. Honeybee weight increased with increasing amounts of larval food, but the effect seemed to vanish after a week. These results show the complexity and adaptability of the honeybee division of labor. They show the importance of the biogenic amines octopamine and tyramine and of the corresponding receptors AmOARα1 and AmTAR1 in modulating the transition from inhive bees to foragers. Furthermore, they show that in-vitro rearing has no effects on nursing behavior, but that it speeds up the transition from nursing to foraging, showing strong similarities to effects of larval pollen undernourishment. However, larval malnourishment showed almost no effects on honeybee task allocation or physiology. It seems that larval malnourishment can be easily compensated during the early lifetime of adult honeybees. N2 - Honigbienen gehören zu den wenigen Spezies, die in eusozialen Gemeinschaften leben. Die eierlegende Königin und die männlichen Drohnen dienen nur der Fortpflanzung. Alle anderen Arbeiten von den sterilen Arbeiterinnen ausgeführt werden. Die Arbeitsteilung wird meistens anhand des Alters der Bienen organisiert. Junge Arbeiterinnen bleiben im Inneren der Kolonie und führen beispielsweise Putzarbeiten und Ammentätigkeiten aus. Mit zunehmendem Alter verlagern sich ihre Tätigkeiten immer mehr in Richtung des Nestausgangs wo sie, unteranderem als Wächterbienen, den Stockeingang bewachen. Die ältesten Honigbienen verlassen das Nest, um Honig, Pollen, Wasser oder Propolis zu sammeln, bis sie am Ende sterben. Allerdings können unvorhersehbare Ereignisse dazu führen, dass sich die Kolonie anpassen muss, um nicht unterzugehen. Krankheiten wie der Flügeldeformationsvirus oder die, durch den Menschen eingeführte, Varroa destructor Milbe können auf einen Schlag eine große Zahl an Bienen auslöschen. Des Weiteren können beispielsweise starke Unwetter dafür sorgen, dass etliche Sammlerinnen auf ihrem Sammelflug sterben und die Kolonie ohne neuen Nektar oder Pollen zurückgelassen wird. Es liegt auf der Hand, dass eine starre Arbeitsverteilung nicht ausreicht, um solchen Umständen entgegenzuwirken und, dass eine gewisse Flexibilität notwendig ist. In meiner Dissertation habe ich eine weitreichende Anzahl an verhaltensbiologischen und molekularbiologischen Techniken verwendet, um die molekularen und physiologischen Mechanismen der Arbeitsteilung bei Honigbienen aufzuklären, vor allem im Bezug auf den Übergang von Ammenbienen zu Sammlerinnen. Es ist seit langer Zeit bekannt, dass die Gene AmOARα1, AmTAR1, Amfor und Vitellogenin beim Übergang von Ammenbienen zu Sammlerinnen von zentraler Bedeutung sind. Deshalb habe ich die Expression dieser Gene, sowohl im Gehirn als auch im Fettkörper, in genau diesem Zusammenhang betrachtet und die unterschiedlichen Veränderungen der Expressionsmuster während dieser wichtigen Phase im Leben einer Honigbiene analysiert. Ich konnte zeigen, dass sowohl die mRNA Expression des AmOARα1 und des Amforα beim Übergang von Ammenbienen zu Sammlerinnen anstieg, während die Expression der anderen Kandidatengene im gleichen Zeitraum sowohl im Gehirn als auch im Fettkörper abfiel. Interessanterweise zeigten die Expressionsmuster des AmOARα1 und des Am3 TAR1, während der Orientierungsflüge, genau in die entgegengesetzte Richtung. Zusätzlich habe ich mir bei denselben Bienen auch den Juvenilhormongehalt in der Hämolymphe und die Menge an Triglyceriden im Fettkörper angeschaut. Der Juvenilhormongehalt nahm schlagartig zu, als die Bienen mit dem Sammeln begannen. Die Menge an Triglyceriden nahm allerdings von Ammenbienen, über Bienen während des Orientierungsfluges zu Sammlerinnen konstant ab. Des Weiteren war bereits bekannt, dass sich Ammenbienen und Sammlerinnen nicht nur auf genetischer, sondern auch auf verhaltensbiologischer und physiologischer Ebene voneinander unterscheiden. Zum Beispiel sind Sammlerinnen empfindlicher für Licht und Saccharose. Ich stellte die Hypothese auf, dass die Empfindlichkeit von Honigbienen für solche Schwellen durch biogene Amine, insbesondere Oktopamin und Tyramin, moduliert werden kann. Oktopamin sollte die Empfindlichkeit von Bienen erhöhen, wohingegen Tyramin diese verringern sollte. Hierfür injizierte ich Stockbienen und Sammlerinnen beide biogenen Amine und analysierte die Rezeptorantwort mit einem Elektroretinogramm (ERG) und die Lichtempfindlichkeit in einer Phototaxisarena. Oktopamininjektion führte dazu, dass die Rezeptorantwort im ERG erhöht wurde und dass beide Gruppen eine erhöhte Lichtempfindlichkeit aufwiesen. Tyramin hatte in beiden Experimenten genau den gegenteiligen Effekt. Allerdings kann der Ammen-Sammlerinnen-Übergang nicht nur durch biogene Amine moduliert werden, auch die Ernährung hat einen großen Einfluss. Zum Beispiel fangen unterernährte Honigbienen eher an zu sammeln als satte Honigbienen. Des Weiteren sollte auch die larvale Unterernährung bereits einen Einfluss auf die spätere Arbeitsteilung haben, da man bei Arbeiterinnen, die im Larvenstadium bereits unterernährt waren, eine erhöhte Menge an Juvenilhormon festgestellt hatte. Dies sieht man auch beim Übergang von Ammenbienen zu Sammlerinnen. Deshalb nutzte ich eine Methode zur artifiziellen Aufzucht von Honigbienen, um die Standarddiät, die diese normalerweise erhalten, zu variieren. Allerdings musste ich zuerst den Effekt der in-vitro Aufzucht auf im Stock aufgezogene Honigbienen untersuchen. Ich konnte zeigen, dass die artifizielle Aufzucht das Sammelverhalten erwachsener Honigbienen signifikant beeinflusste, während das Ammenverhalten der in-vitro aufgezogenen Bienen nicht beeinflusst wurde. Artifiziell aufgezogene Honigbienen begannen, im Vergleich zu normalen Bienen, früher zu sammeln und sammelten für eine kürzere Zeit. Danach zog ich unterernährte, normal ernährte und überfütterte Honigbienen in-vitro 4 auf. Ich fand Unterschiede im Gewicht zwischen den Behandlungsgruppen. Unterernährte Bienen waren die leichtesten und überfütterte Bienen wogen am meisten. Dieser Unterschied verschwand aber über die Zeit. Des Weiteren konnte ich keinen Einfluss der Ernährung auf das Ammenverhalten oder das Sammelverhalten zeigen. Dieser Ergebnisse zeigen sowohl die Komplexität als auch das Anpassungsvermögen der Arbeitsteilung von Honigbienen. Sie zeigen, dass sowohl die beiden biogenen Amine Oktopamin und Tyramin, als auch die dazugehörigen Rezeptoren AmOARα1 und AmTAR1 bei der Modulation des Ammen-Sammlerinnen-Übergangs eine große Rolle spielen. Des Weiteren zeigen die Ergebnisse des Vergleichs von artifiziell und im Stock aufgezogenen Bienen, starke Gemeinsamkeiten zu einer larvalen Unterernährung mit Pollen. Jedoch scheint eine allgemeine larvale Unterernährung kaum einen Effekt auf den AmmenSammlerinnen-Übergang zu haben. Diese scheint während der ersten Lebenstage von Honigbienen relativ leicht kompensiert werden zu können. KW - Biene KW - juvenile hormone KW - nurse bee KW - forager KW - division of labor KW - malnourishment KW - diet KW - bee KW - honeybee Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-289352 ER - TY - JOUR A1 - Kortmann, Mareike A1 - Angelstam, Per A1 - Mayer, Marius A1 - Leibl, Franz A1 - Reichert, Jessica A1 - Thorn, Christine A1 - Thorn, Simon T1 - Disturbance severity and human–nature relationships: A new approach to analyze people’s well-being along a bark beetle infestation gradient JF - Forests N2 - Contact to nature and greenspace is important for emotional well-being and can promote human health. Forest landscapes provide such access to greenspace, especially in protected areas. However, forested protected areas are impacted by natural disturbances such as bark beetle infestations. On the one hand, such disturbances have positive impacts on ecological processes and biodiversity. On the other hand, they have allegedly negative impacts on the recreational value of a landscape. Limited knowledge about the public’s perception of forests subject to natural disturbances still hampers forest management to balance ecological functions and visitors’ recreational experience. Thus, our aim was to determine how attitudes towards nature influence the personal well-being in a naturally disturbed landscape. We investigated self-reported well-being and attitudes towards nature in a standardized questionnaire-based survey of 1008 German inhabitants in an experimentally adapted landscape visualization. Self-reported well-being was generally highest in landscapes with relatively few bark-beetle-killed trees. This was especially the case for people who felt included with nature and preferred an appreciative use or preservation of nature. Conversely, people who had previously visited a national park with visible bark beetle infestations rated their personal well-being highest in landscapes with larger proportions of beetle-killed trees. Our results indicate that it is necessary to analyze people’s knowledge about and relations to forest landscapes as well as concepts of nature conservation, natural landscapes, and biodiversity to gain a better understanding of people’s perceptions of natural disturbances. KW - bark beetle disturbance KW - major environmental values KW - well-being KW - inclusion of nature in one’s self KW - national park Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297429 SN - 1999-4907 VL - 13 IS - 11 ER - TY - JOUR A1 - Henriksson, Sofia A1 - Calderón-Montaño, José Manuel A1 - Solvie, Daniel A1 - Warpman Berglund, Ulrika A1 - Helleday, Thomas T1 - Overexpressed c-Myc sensitizes cells to TH1579, a mitotic arrest and oxidative DNA damage inducer JF - Biomolecules N2 - Previously, we reported that MTH1 inhibitors TH588 and TH1579 selectively induce oxidative damage and kill Ras-expressing or -transforming cancer cells, as compared to non-transforming immortalized or primary cells. While this explains the impressive anti-cancer properties of the compounds, the molecular mechanism remains elusive. Several oncogenes induce replication stress, resulting in under replicated DNA and replication continuing into mitosis, where TH588 and TH1579 treatment causes toxicity and incorporation of oxidative damage. Hence, we hypothesized that oncogene-induced replication stress explains the cancer selectivity. To test this, we overexpressed c-Myc in human epithelial kidney cells (HA1EB), resulting in increased proliferation, polyploidy and replication stress. TH588 and TH1579 selectively kill c-Myc overexpressing clones, enforcing the cancer cell selective killing of these compounds. Moreover, the toxicity of TH588 and TH1579 in c-Myc overexpressing cells is rescued by transcription, proteasome or CDK1 inhibitors, but not by nucleoside supplementation. We conclude that the molecular toxicological mechanisms of how TH588 and TH1579 kill c-Myc overexpressing cells have several components and involve MTH1-independent proteasomal degradation of c-Myc itself, c-Myc-driven transcription and CDK activation. KW - MTH1 KW - TH588 KW - TH1579 KW - c-Myc KW - replication stress KW - DNA damage KW - cell death KW - cancer Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297547 SN - 2218-273X VL - 12 IS - 12 ER - TY - INPR A1 - Dandekar, Thomas T1 - Protein folding and crystallization applied to qubit interactions and fundamental physics yields a modified inflation model for cosmology N2 - Protein folding achieves a clear solution structure in a huge parameter space (the so-called protein folding problem). Proteins fold in water, and get by this a highly ordered structure. Finally, inside a protein crystal for structure resolution, you have everywhere the same symmetries as there is everywhere the same unit cell. We apply this to qubit interactions to do fundamental physics: in a modified cosmology, we replace the big bang by a condensation event in an eternal all-encompassing ocean of free qubits. Interactions of qubits in the qubit ocean are quite rare but provide a nucleus or seed for a new universe (domain) as the qubits become decoherent and freeze-out into defined bit ensembles. Second, we replace inflation by a crystallization event triggered by the nucleus of interacting qubits to which rapidly more and more qubits attach (like in everyday crystal growth). The crystal unit cell guarantees same symmetries everywhere inside the crystal. The textbook inflation scenario to explain the same laws of nature in our domain is replaced by the unit cell of the crystal formed. Interacting qubits solidify, quantum entropy decreases (but increases in the ocean around). In a modified inflation scenario, the interacting qubits form a rapidly growing domain where the n**m states become separated ensemble states, rising long-range forces stop ultimately further growth. Then standard cosmology with the hot fireball model takes over. Our theory agrees well with lack of inflation traces in cosmic background measurements. We explain by cosmological crystallization instead of inflation: early creation of large-scale structure of voids and filaments, supercluster formation, galaxy formation, and the dominance of matter: the unit cell of our crystal universe has a matter handedness avoiding anti-matter. We prove initiation of qubit interactions can only be 1,2,4 or 8-dimensional (agrees with E8 symmetry of our universe). Repulsive forces at ultrashort distances result from quantization, long-range forces limit crystal growth. Crystals come and go in the qubit ocean. This selects for the ability to lay seeds for new crystals, for self-organization and life-friendliness. The phase space of the crystal agrees with the standard model of the basic four forces for n quanta. It includes all possible ensemble combinations of their quantum states m, a total of n**m states. Neighbor states reach according to transition possibilities (S-matrix) with emergent time from entropic ensemble gradients. However, in our four dimensions there is only one bit overlap to neighbor states left (almost solid, only below Planck quantum there is liquidity left). The E8 symmetry of heterotic string theory has six curled-up, small dimensions which help to keep the qubit crystal together and will never expand. Mathematics focusses on the Hurwitz proof applied to qubit interaction, a toy model of qubit interaction and repulsive forces of qubits. Vacuum energy gets appropriate low inside the crystal. We give first energy estimates for free qubits vs bound qubits, misplacements in the qubit crystal and entropy increase during qubit decoherence / crystal formation. Scalar fields for color interaction/confinement and gravity are derived from the qubit-interaction field. KW - protein folding KW - crystallization KW - qubit interaction KW - decoherence KW - modified inflation Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-346156 ER - TY - THES A1 - Kohl, Patrick Laurenz T1 - The buzz beyond the beehive: population demography, parasite burden and limiting factors of wild-living honeybee colonies in Germany T1 - Das Summen fern des Bienenstocks: Populationsdemographie, Parasitenlast und limitierende Faktoren wildlebender Honigbienenvölker in Deutschland N2 - The western honeybee (Apis mellifera) is widely known as the honey producer and pollinator managed by beekeepers but neglected as a wild bee species. Central European honeybee populations have been anthropogenically disturbed since about 1850 through introgression and moderate artificial selection but have never been truly domesticated due to a lack of mating control. While their decline in the wild was historically attributed to the scarcity of nesting cavities, a contemporary view considers the invasion of the parasitic mite Varroa destructor in the 1970s as the major driver. However, there are no longitudinal population data available that could substantiate either claim. Based on the insight that introduced European honeybees form viable wild populations in eastern North America and reports on the occurrence of wild-living colonies from various European countries, we systematically studied the ecology of wild-living honeybees in Germany. First, we investigated whether wild-living honeybees colonising German forests form a self-sustaining population. Second, we asked how the parasite burden of wild-living colonies relates to that of managed colonies. And third, we explored whether the winter mortality of wild-living colonies is associated with parasite burden, nest depredation, or the lack of resources on the landscape scale. Between 2017 and 2021, we monitored listed trees with black woodpecker cavities for honeybees in the managed forests of three study regions (Swabian Alb, counties Coburg and Lichtenfels, county Weilheim-Schongau). Continuity of occupation was determined using microsatellite genetic markers. Wild-living colonies predictably colonised forests in summer, when about 10% of all cavities were occupied. The annual colony survival rate and colony lifespan (based on N=112 colonies) were 10.6% and 0.6 years, with 90% of colonies surviving summer (July–September), 16% surviving winter (September–April), and 72% surviving spring (April–July). The average maximum and minimum colony densities were 0.23 (July) and 0.02 (April) colonies per km^2. During the (re-)colonisation of forests in spring, swarms preferred cavities that had already been occupied by other honeybee colonies. We estimate the net reproductive rate of the population to be R0= 0.318, meaning that it is currently not self-sustaining but maintained by the annual immigration of swarms from managed hives. The wild-living colonies are feral in a behavioural sense. We compared the occurrence of 18 microparasites among feral colonies (N=64) and managed colonies (N=74) using qPCR. Samples were collected in four regions (the three regions mentioned above and the city of Munich) in July 2020; they consisted of 20 workers per colony captured at flight entrances. We distinguished five colony types representing differences in colony age and management histories. Besides strong regional variation, feral colonies consistently hosted fewer microparasite taxa (median: 5, range 1–8) than managed colonies (median: 6, range 4–9) and had different parasite communities. Microparasites that were notably less prevalent among feral colonies were Trypanosomatidae, Chronic bee paralysis virus, and Deformed wing viruses A and B. In the comparison of five colony types, parasite burden was lowest in newly founded feral colonies, intermediate in overwintered feral colonies and managed nucleus colonies, and highest in overwintered managed colonies and hived swarms. This suggests that the natural mode of colony reproduction by swarming, which creates pauses in brood production, and well-dispersed nests, which reduce horizontal transmission, explain the reduced parasite burden in feral compared to managed colonies. To explore the roles of three potential drivers of feral colony winter mortality, we combined colony observations gathered during the monitoring study with data on colony-level parasite burden, observations and experiments on nest depredation, and landscape analyses. There was no evidence for an effect of summertime parasite burden on subsequent winter mortality: colonies that died (N=57) did not have a higher parasite burden than colonies that survived (N=10). Camera traps (N=15) installed on cavity trees revealed that honeybee nests are visited by a range of vertebrate species throughout the winter at rates of up to 10 visits per week. Four woodpecker species, great tits, and pine martens acted as true nest depredators. The winter survival rate of colonies whose nest entrances were protected by screens of wire mesh (N=32) was 50% higher than that of colonies with unmanipulated entrances (N=40). Analyses of land cover maps revealed that the landscapes surrounding surviving colonies (N=19) contained on average 6.4 percentage points more resource-rich cropland than landscapes surrounding dying colonies (N=94). We estimate that tens of thousands of swarms escape from apiaries each year to occupy black woodpecker cavities and other hollow spaces in Germany and that feral colonies make up about 5% of the regional honeybee populations. They are unlikely to contribute disproportionately to the spread of bee diseases. Instead, by spatially complementing managed colonies, they contribute to the pollination of wild plants in forests. Honeybees occupying tree cavities likely have various effects on forest communities by acting as nest site competitors or prey, and by accumulating biomass in tree holes. Nest depredation (a consequence of a lack of well-protected nest sites) and food resource limitation seem to be more important than parasites in hampering feral colony survival. The outstanding question is how environmental and intrinsic factors interact in preventing population establishment. Nest boxes with movable frames could be used to better study the environmental drivers of feral colonies’ mortality. Pairs of wild (self-sustaining) and managed populations known to exist outside Europe could provide answers to whether modern apiculture creates honeybee populations maladapted to life in the wild. In Europe, large continuous forests might represent evolutionary refuges for wild honeybees. N2 - Die Honigbiene (Apis mellifera) ist als Nutztier weitbekannt, doch als Wildtier vernachlässigt. Seit etwa 1850 sind ihre Populationen in Mitteleuropa durch Introgression und moderate künstliche Selektion vom Menschen beeinflusst. Die Art wurde jedoch aufgrund fehlender Paarungskontolle nie wirklich domestiziert. Früher wurde der Rückgang wildlebender Honigbienen dem Verlust geeigneter Nistplätze zugeschrieben. Heute wird meist die Bienenmilbe Varroa destructor als Hauptursache angenommen. Es gibt allerdings keine Langzeitdaten, welche diese Annahmen stützen könnten. Basierend auf der Erkenntnis, dass eingeführte Honigbienen in Nordamerika stabile wilde Populationen bilden, und aufgrund von Berichten über das Vorkommen wildlebender Bienenvölker in verschiedenen Ländern Europas, widmeten wir uns dem systematischen Studium wildlebender Honigbienen in Deutschland. Zunächst untersuchten wir, ob waldbewohnende Bienenvölker eine selbsterhaltende Population bilden. Zweitens stellten wir die Frage, inwiefern sich wildlebende und imkerlich gehaltene Völker in ihrer Parasitenlast unterscheiden. Drittens testeten wir, ob Winterverluste wildlebender Bienenvölker mit Parasitendruck, Nestprädation oder mangelndem Nahrungsangebot auf Landschaftsebene in Verbindung stehen. In Wirtschaftswäldern dreier Untersuchungsgebiete (Schwäbische Alb, Landkreise Coburg und Lichtenfels, Landkreis Weilheim-Schongau) kontrollierten wir zwischen 2017 und 2021 bekannte Höhlenbäume des Schwarzspechts auf Besiedlung durch Honigbienen. Das Überleben einzelner Bienenvölker wurde zusätzlich mittels Analyse von Mikrosatelliten DNA überprüft. Nach verlässlichem Muster besiedelten Honigbienen jeden Sommer etwa 10% der Baumhöhlen. Die jährliche Überlebensrate und die Lebenserwartung der Völker (N=112) betrugen 10,6% und 0,6 Jahre, wobei 90% den Sommer (Juli–September), 16% den Winter (September–April) und 72% das Frühjahr (April–Juli) überlebten. Die durchschnittliche maximale (Juli) und minimale (April) Koloniedichte betrug 0,23 bzw. 0,02 Bienenvölker pro km^2. Während der (Wieder)Besiedlung von Wäldern im Frühjahr bevorzugten Bienenschwärme solche Baumhöhlen, welche zuvor schon von Bienen besiedelt worden waren. Die Nettoreproduktionsrate der wildlebenden Population wird auf R0= 0,318 geschätzt, was bedeutet, dass diese zurzeit nicht selbsterhaltend ist, sondern durch die jährliche Einwanderung von Bienenschwärmen aus der Imkerei aufrechterhalten wird. Wir untersuchten wildlebende (N=64) und imkerlich gehaltene Bienenvölker (N=74) auf den Befall mit 18 verschiedenen Mikroparasiten mittels qPCR. Die Proben stammten aus den drei oben genannten Gebieten sowie aus dem Stadtgebiet von München. Eine Probe bestand aus 20 Arbeiterinnen, welche am Flugloch gefangen wurden. Wir unterschieden fünf Kolonietypen aufgrund des Alters (jünger oder älter als ein Jahr) und der unmittelbaren Geschichte der Bewirtschaftung durch Imkerinnen und Imker. Abgesehen von regionalen Unterschieden in der Parasitenlast waren wildlebende Völker mit einer geringeren Anzahl Parasitentaxa befallen (Median: 5, Spanne: 1–8) als imkerlich gehaltene Völker (Median: 6, Spanne: 4–9) und wiesen eine veränderte Zusammensetzung von Parasiten auf. Seltener bei wildlebenden Bienenvölkern waren besonders Trypanosomatidae, das Chronische-Paralysevirus, sowie die Flügeldeformationsviren A und B. Im Vergleich der fünf Kolonietypen war die Parasitenlast bei neu gegründeten wildlebenden Völkern am geringsten, intermediär bei überwinterten wildlebenden Völkern und Brutablegern, und am höchsten bei überwinterten Wirtschaftsvölkern und bei durch Schwärme gegründeten imkerlich gehaltenen Völkern. Dies deutet darauf hin, dass das Schwärmen (Entstehung von Brutpausen) sowie die größere Distanz zwischen Nestern (Verminderung der horizontalen Krankheitsübertragung) die geringere Parasitenlast wildlebender Bienenvölker erklären. Wir kombinierten Beobachtungen zum Winterüberleben aus dem Monitoring mit Daten zur Parasitenlast, mit Beobachtungen und Experimenten zur Nestprädation und mit Landschaftsanalysen. Es ergab sich kein Hinweis auf einen Zusammenhang zwischen Parasitenlast im Sommer und anschließendem Überwinterungserfolg: Völker, welche den Winter nicht überlebten (N=57), hatten zuvor keine höhere Parasitenlast als solche, welche den Winter überlebten (N=10). Kamerafallen (N=15) offenbarten, dass Honigbienennester im Winter von einer Vielzahl von Vögeln und Säugern mit bis zu 10 Besuchen pro Woche heimgesucht werden. Vier Spechtarten, Kohlmeisen und Baummarder wurden als echte Nestplünderer identifiziert. Bienenvölker, deren Nesteingang mit Maschendraht geschützt war (N=32), hatten eine 50% höhere Winterüberlebensrate als Völker ohne Schutz (N=40). Die Analyse von Landnutzungskarten zeigte, dass sich Bienenvölker, welche den Winter überlebten (N=19), in Landschaften mit durchschnittlich 6,4% höherem Anteil von Ackerflächen befanden als solche, die den Winter nicht überlebten (N=94). Wir schätzen, dass in Deutschland jährlich zehntausende Schwärme von Bienenständen entfliehen, um sich in Spechthöhlen oder anderen Hohlräumen anzusiedeln. Der Anteil wildlebender Völker an der Gesamtbienenpopulation beträgt im Sommer etwa 5%. Sie spielen vermutlich eine untergeordnete Rolle bei der Verbreitung von Bienenkrankheiten. Durch die Ergänzung imkerlich gehaltener Völker in Waldgebieten tragen sie zur Bestäubung waldbewohnender Pflanzenarten bei. Die Besiedlung von Baumhöhlen sollte vielseitige Auswirkungen auf Lebensgemeinschaften im Wald haben: Bienenvölker konkurrieren um Nistplätze, sind reiche Beute im Winter und akkumulieren organisches Material. Nestprädation (eine Folge des Mangels an sicheren Nisthöhlen) und Ressourcenlimitierung spielen offenbar derzeit eine größere Rolle als Parasiten bei der Erklärung von Winterverlusten. Eine offene Frage ist, inwiefern Umwelt und genetische Dispositionen die Etablierung wilder Honigbienenpopulationen verhindern. Künstliche Nistkästen könnten genutzt werden, um die Rolle von Umweltfaktoren genauer zu untersuchen. Populationen wilder Honigbienen außerhalb Europas könnten Erkenntnisse dazu liefern, inwiefern sich die moderne Imkerei auf die Anpassungen der Honigbienen als Wildtier auswirkt. In Europa könnten große zusammenhängende Waldgebiete als evolutionäre Refugien für wilde Honigbienen dienen. KW - Biene KW - Insektensterben KW - Wald KW - Spechte KW - Imkerei KW - wild honey bees KW - swarming KW - tree cavity KW - monitoring KW - bee diseases KW - Wilde Honigbienen KW - Bienenschwarm KW - Baumhöhle KW - Monitoring KW - Bienenkrankheiten KW - Nisthöhle Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-330327 ER - TY - THES A1 - Bergmann Borges, Alyssa T1 - The endo-lysosomal system of \(Trypanosoma\) \(brucei\): insights from a protist cell model T1 - Das Endo-lysosomale System von \(Trypanosoma\) \(brucei\): Erkenntnisse aus einem Protisten-Zellmodell N2 - Most of the studies in cell biology primarily focus on models from the opisthokont group of eukaryotes. However, opisthokonts do not encompass the full diversity of eukaryotes. Thus, it is necessary to broaden the research focus to other organisms to gain a comprehensive understanding of basic cellular processes shared across the tree of life. In this sense, Trypanosoma brucei, a unicellular eukaryote, emerges as a viable alternative. The collaborative efforts in genome sequencing and protein tagging over the past two decades have significantly expanded our knowledge on this organism and have provided valuable tools to facilitate a more detailed analysis of this parasite. Nevertheless, numerous questions still remain. The survival of T. brucei within the mammalian host is intricately linked to the endo-lysosomal system, which plays a critical role in surface glycoprotein recycling, antibody clearance, and plasma membrane homeostasis. However, the dynamics of the duplication of the endo-lysosomal system during T. brucei proliferation and its potential relationship with plasma membrane growth remain poorly understood. Thus, as the primary objective, this thesis explores the endo-lysosomal system of T. brucei in the context of the cell cycle, providing insights on cell surface growth, endosome duplication, and clathrin recruitment. In addition, the study revisits ferritin endocytosis to provide quantitative data on the involvement of TbRab proteins (TbRab5A, TbRab7, and TbRab11) and the different endosomal subpopulations (early, late, and recycling endosomes, respectively) in the transport of this fluid-phase marker. Notably, while these subpopulations function as distinct compartments, different TbRabs can be found within the same region or structure, suggesting a potential physical connection between the endosomal subpopulations. The potential physical connection of endosomes is further explored within the context of the cell cycle and, finally, the duplication and morphological plasticity of the lysosome are also investigated. Overall, these findings provide insights into the dynamics of plasma membrane growth and the coordinated duplication of the endo-lysosomal system during T. brucei proliferation. The early duplication of endosomes suggests their potential involvement in plasma membrane growth, while the late duplication of the lysosome indicates a reduced role in this process. The recruitment of clathrin and TbRab GTPases to the site of endosome formation supports the assumption that the newly formed endosomal system is active during cell division and, consequently, indicates its potential role in plasma membrane homeostasis. Furthermore, considering the vast diversity within the Trypanosoma genus, which includes ~500 described species, the macroevolution of the group was investigated using the combined information of the 18S rRNA gene sequence and structure. The sequence-structure analysis of T. brucei and other 42 trypanosome species was conducted in the context of the diversity of Trypanosomatida, the order in which trypanosomes are placed. An additional analysis focused on Trypanosoma highlighted key aspects of the group’s macroevolution. To explore these aspects further, additional trypanosome species were included, and the changes in the Trypanosoma tree topology were analyzed. The sequence-structure phylogeny confirmed the independent evolutionary history of the human pathogens T. brucei and Trypanosoma cruzi, while also providing insights into the evolution of the Aquatic clade, paraphyly of groups, and species classification into subgenera. N2 - Die meisten Studien in der Zellbiologie konzentrieren sich in erster Linie auf Modelle aus der Opisthokont-Gruppe der Eukaryonten. Die Opisthokonten umfassen jedoch nicht die gesamte Vielfalt der Eukaryonten. Daher ist es notwendig, den Forschungsschwerpunkt auf andere Organismen auszuweiten, um ein umfassendes Verständnis grundlegender zellulärer Prozesse zu erlangen, die im gesamten Lebensbaum vorkommen. In diesem Sinne stellt Trypanosoma brucei, ein einzelliger Eukaryote, eine brauchbare Alternative dar. Die gemeinsamen Anstrengungen bei der Genomsequenzierung und der Markierung von Proteinen in den letzten zwei Jahrzehnten haben unser Wissen über diesen Organismus erheblich erweitert und wertvolle Instrumente für eine detailliertere Analyse dieses Parasiten bereitgestellt. Dennoch bleiben noch zahlreiche Fragen offen. Das Überleben von T. brucei im Säugetierwirt ist eng mit dem endo-lysosomalen System verknüpft, das eine entscheidende Rolle beim Recycling von Oberflächenglykoproteinen, der Antikörper-Clearance und der Homöostase der Plasmamembran spielt. Die Dynamik der Verdoppelung des endo-lysosomalen Systems während der Vermehrung von T. brucei und seine mögliche Beziehung zum Wachstum der Plasmamembran sind jedoch noch wenig bekannt. In dieser Arbeit wird daher das endo-lysosomale System von T. brucei im Kontext des Zellzyklus untersucht, um Erkenntnisse über das Wachstum der Zelloberfläche, die Verdopplung der Endosomen und die Clathrin-Rekrutierung zu gewinnen. Darüber hinaus wird in der Studie die Ferritin-Endozytose erneut untersucht, um quantitative Daten über die Beteiligung der TbRab-Proteine (TbRab5A, TbRab7 und TbRab11) und der verschiedenen endosomalen Subpopulationen (frühe, späte bzw. Recycling-Endosomen) am Transport dieses Flüssigphasenmarkers zu erhalten. Bemerkenswert ist, dass diese Subpopulationen zwar als unterschiedliche Kompartimente fungieren, aber verschiedene TbRabs in derselben Region oder Struktur gefunden werden können, was auf eine mögliche physische Verbindung zwischen den endosomalen Subpopulationen hindeutet. Die potenzielle physikalische Verbindung von Endosomen wird im Zusammenhang mit dem Zellzyklus weiter erforscht, und schließlich werden auch die Verdopplung und die morphologische Plastizität des Lysosoms untersucht. Insgesamt bieten diese Ergebnisse Einblicke in die Dynamik des Plasmamembranwachstums und die koordinierte Verdopplung des endo-lysosomalen Systems während der Proliferation von T. brucei. Die frühe Verdoppelung der Endosomen deutet auf ihre mögliche Beteiligung am Plasmamembranwachstum hin, während die späte Verdoppelung der Lysosomen auf eine geringere Rolle in diesem Prozess hindeutet. Die Rekrutierung von Clathrin- und TbRab-GTPasen an der Stelle der Endosomenbildung unterstützt die Annahme, dass das neu gebildete endosomale System während der Zellteilung aktiv ist, und deutet folglich auf seine potenzielle Rolle bei der Homöostase der Plasmamembran hin. In Anbetracht der enormen Vielfalt innerhalb der Gattung Trypanosoma, die etwa 500 beschriebene Arten umfasst, wurde die Makroevolution der Gruppe anhand der kombinierten Informationen der 18S rRNA-Gensequenz und Struktur untersucht. Die Sequenz-Struktur-Analyse von T. brucei und anderen 42 Trypanosomen-Arten wurde im Zusammenhang mit der Vielfalt der Trypanosomatida, der Ordnung, in die Trypanosomen eingeordnet werden, durchgeführt. Eine zusätzliche Analyse, die sich auf Trypanosoma konzentrierte, hob Schlüsselaspekte der Makroevolution dieser Gruppe hervor. Um diese Aspekte weiter zu erforschen, wurden zusätzliche Trypanosomenarten einbezogen und die Veränderungen in der Topologie des Trypanosoma-Baums analysiert. Die Sequenz-Struktur-Phylogenie bestätigte die unabhängige Evolutionsgeschichte der humanen Krankheitserreger T. brucei und Trypanosoma cruzi, während sie gleichzeitig Einblicke in die Evolution der aquatischen Klade, die Paraphylie von Gruppen und die Klassifizierung der Arten in Untergattungen lieferte. KW - 18S rRNA KW - Endocytose KW - Zellzyklus KW - Phylogenie KW - Endocytosis KW - Cell cycle KW - Trypanosoma KW - Phylogeny KW - Sequence-Structure KW - Endosomes KW - Lysosome Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-329248 ER - TY - JOUR A1 - Kotlyar, Mischa J. A1 - Krebs, Markus A1 - Solimando, Antonio Giovanni A1 - Marquardt, André A1 - Burger, Maximilian A1 - Kübler, Hubert A1 - Bargou, Ralf A1 - Kneitz, Susanne A1 - Otto, Wolfgang A1 - Breyer, Johannes A1 - Vergho, Daniel C. A1 - Kneitz, Burkhard A1 - Kalogirou, Charis T1 - Critical evaluation of a microRNA-based risk classifier predicting cancer-specific survival in renal cell carcinoma with tumor thrombus of the inferior vena cava JF - Cancers N2 - (1) Background: Clear cell renal cell carcinoma extending into the inferior vena cava (ccRCC\(^{IVC}\)) represents a clinical high-risk setting. However, there is substantial heterogeneity within this patient subgroup regarding survival outcomes. Previously, members of our group developed a microRNA(miR)-based risk classifier — containing miR-21-5p, miR-126-3p and miR-221-3p expression — which significantly predicted the cancer-specific survival (CSS) of ccRCC\(^{IVC}\) patients. (2) Methods: Examining a single-center cohort of tumor tissue from n = 56 patients with ccRCC\(^{IVC}\), we measured the expression levels of miR-21, miR-126, and miR-221 using qRT-PCR. The prognostic impact of clinicopathological parameters and miR expression were investigated via single-variable and multivariable Cox regression. Referring to the previously established risk classifier, we performed Kaplan–Meier analyses for single miR expression levels and the combined risk classifier. Cut-off values and weights within the risk classifier were taken from the previous study. (3) Results: miR-21 and miR-126 expression were significantly associated with lymphonodal status at the time of surgery, the development of metastasis during follow-up, and cancer-related death. In Kaplan–Meier analyses, miR-21 and miR-126 significantly impacted CSS in our cohort. Moreover, applying the miR-based risk classifier significantly stratified ccRCC\(^{IVC}\) according to CSS. (4) Conclusions: In our retrospective analysis, we successfully validated the miR-based risk classifier within an independent ccRCC\(^{IVC}\) cohort. KW - kidney cancer KW - RCC KW - venous infiltration KW - biomarker KW - miR KW - risk stratification Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311040 SN - 2072-6694 VL - 15 IS - 7 ER - TY - JOUR A1 - Rackevei, Antonia S. A1 - Borges, Alyssa A1 - Engstler, Markus A1 - Dandekar, Thomas A1 - Wolf, Matthias T1 - About the analysis of 18S rDNA sequence data from trypanosomes in barcoding and phylogenetics: tracing a continuation error occurring in the literature JF - Biology N2 - The variable regions (V1–V9) of the 18S rDNA are routinely used in barcoding and phylogenetics. In handling these data for trypanosomes, we have noticed a misunderstanding that has apparently taken a life of its own in the literature over the years. In particular, in recent years, when studying the phylogenetic relationship of trypanosomes, the use of V7/V8 was systematically established. However, considering the current numbering system for all other organisms (including other Euglenozoa), V7/V8 was never used. In Maia da Silva et al. [Parasitology 2004, 129, 549–561], V7/V8 was promoted for the first time for trypanosome phylogenetics, and since then, more than 70 publications have replicated this nomenclature and even discussed the benefits of the use of this region in comparison to V4. However, the primers used to amplify the variable region of trypanosomes have actually amplified V4 (concerning the current 18S rDNA numbering system). KW - RNA secondary structure KW - variable regions KW - V1–V9 KW - V4 KW - V7/V8 KW - Trypanosoma Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297562 SN - 2079-7737 VL - 11 IS - 11 ER - TY - JOUR A1 - Flemming, S. A1 - Hankir, M. A1 - Ernestus, R.-I. A1 - Seyfried, F. A1 - Germer, C.-T. A1 - Meybohm, P. A1 - Wurmb, T. A1 - Vogel, U. A1 - Wiegering, A. T1 - Surgery in times of COVID-19 — recommendations for hospital and patient management JF - Langenbeck's Archives of Surgery N2 - Background The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has escalated rapidly to a global pandemic stretching healthcare systems worldwide to their limits. Surgeonshave had to immediately react to this unprecedented clinical challenge by systematically repurposing surgical wards. Purpose To provide a detailed set of guidelines developed in a surgical ward at University Hospital Wuerzburg to safelyaccommodate the exponentially rising cases of SARS-CoV-2 infected patients without compromising the care of emergencysurgery and oncological patients or jeopardizing the well-being of hospital staff. Conclusions The dynamic prioritization of SARS-CoV-2 infected and surgical patient groups is key to preserving life whilemaintaining high surgical standards. Strictly segregating patient groups in emergency rooms, non-intensive care wards andoperating areas prevents viral spread while adequately training and carefully selecting hospital staff allow them to confidentlyand successfully undertake their respective clinical duties. KW - SARS-CoV-2 KW - COVID-19 KW - Surgery Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231766 SN - 1435-2443 VL - 405 ER - TY - THES A1 - Münch, Luca T1 - Die Rolle transposabler Elemente in der Genese des malignen Melanom im Fischmodell Xiphophorus T1 - The role of transposable elements in malignant melanoma development in the Xiphophorus fish model N2 - Der Name der transposablen Elemente beruht auf ihrer Fähigkeit, ihre genomische Position verändern zu können. Durch Chromosomenaberrationen, Insertionen oder Deletionen können ihre genomischen Transpositionen genetische Instabilität verursachen. Inwieweit sie darüber hinaus regulatorischen Einfluss auf Zellfunktionen besitzen, ist Gegenstand aktueller Forschung ebenso wie die daraus resultierende Frage nach der Gesamtheit ihrer biologischen Signifikanz. Die Weiterführung experimenteller Forschung ist unabdingbar, um weiterhin offenen Fragen nachzugehen. Das Xiphophorus-Melanom-Modell stellt hierbei eines der ältesten Tiermodelle zur Erforschung des malignen Melanoms dar. Durch den klar definierten genetischen Hintergrund eignet es sich hervorragend zur Erforschung des bösartigen schwarzen Hautkrebses, welcher nach wie vor die tödlichste aller bekannten Hautkrebsformen darstellt. Die hier vorliegende Arbeit beschäftigt sich mit der Rolle transposabler Elemente in der malignen Melanomgenese von Xiphophorus. N2 - The term “transposable elements” (TEs) is based on their ability to change their genomic position. Through insertions, deletions or chromosomal aberrations, their genomic mobility can cause genetic instability. The extent to which they further exert regulatory influence on cellular functions is the subject of current research, as is the resulting question of their overall biological significance. To further pursue these questions the continuation of experimental research is indispensable. In this regard, the Xiphophorus- melanoma-model represents one of the oldest animal models for the study of malignant melanoma. Thanks to its clearly defined genetic background, it is excellently suited for research into melanoma, which continues to be the most lethal of all known forms of skin cancer. The work presented here investigated the role of transposable elements in malignant melanomagenesis of Xiphophorus. KW - Transposon KW - Platy KW - Melanom KW - Überexpression KW - Schwertkärpfling KW - Expression KW - expression KW - Xiphophorus KW - xiphophorus Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-289228 ER - TY - JOUR A1 - Yang, Manli A1 - Rajeeve, Karthika A1 - Rudel, Thomas A1 - Dandekar, Thomas T1 - Comprehensive Flux Modeling of Chlamydia trachomatis Proteome and qRT-PCR Data Indicate Biphasic Metabolic Differences Between Elementary Bodies and Reticulate Bodies During Infection JF - Frontiers in Microbiology N2 - Metabolic adaptation to the host cell is important for obligate intracellular pathogens such as Chlamydia trachomatis (Ct). Here we infer the flux differences for Ct from proteome and qRT-PCR data by comprehensive pathway modeling. We compare the comparatively inert infectious elementary body (EB) and the active replicative reticulate body (RB) systematically using a genome-scale metabolic model with 321 metabolites and 277 reactions. This did yield 84 extreme pathways based on a published proteomics dataset at three different time points of infection. Validation of predictions was done by quantitative RT-PCR of enzyme mRNA expression at three time points. Ct’s major active pathways are glycolysis, gluconeogenesis, glycerol-phospholipid (GPL) biosynthesis (support from host acetyl-CoA) and pentose phosphate pathway (PPP), while its incomplete TCA and fatty acid biosynthesis are less active. The modeled metabolic pathways are much more active in RB than in EB. Our in silico model suggests that EB and RB utilize folate to generate NAD(P)H using independent pathways. The only low metabolic flux inferred for EB involves mainly carbohydrate metabolism. RB utilizes energy -rich compounds to generate ATP in nucleic acid metabolism. Validation data for the modeling include proteomics experiments (model basis) as well as qRT-PCR confirmation of selected metabolic enzyme mRNA expression differences. The metabolic modeling is made fully available here. Its detailed insights and models on Ct metabolic adaptations during infection are a useful modeling basis for future studies. KW - metabolic modeling KW - metabolic flux KW - infection biology KW - elementary body KW - reticulate body KW - Chlamydia trachomatis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-189434 SN - 1664-302X VL - 10 IS - 2350 ER - TY - JOUR A1 - Yadav, Preeti A1 - Selvaraj, Bhuvaneish T. A1 - Bender, Florian L. P. A1 - Behringer, Marcus A1 - Moradi, Mehri A1 - Sivadasan, Rajeeve A1 - Dombert, Benjamin A1 - Blum, Robert A1 - Asan, Esther A1 - Sauer, Markus A1 - Julien, Jean-Pierre A1 - Sendtner, Michael T1 - Neurofilament depletion improves microtubule dynamics via modulation of Stat3/stathmin signaling JF - Acta Neuropathologica N2 - In neurons, microtubules form a dense array within axons, and the stability and function of this microtubule network is modulated by neurofilaments. Accumulation of neurofilaments has been observed in several forms of neurodegenerative diseases, but the mechanisms how elevated neurofilament levels destabilize axons are unknown so far. Here, we show that increased neurofilament expression in motor nerves of pmn mutant mice, a model of motoneuron disease, causes disturbed microtubule dynamics. The disease is caused by a point mutation in the tubulin-specific chaperone E (Tbce) gene, leading to an exchange of the most C-terminal amino acid tryptophan to glycine. As a consequence, the TBCE protein becomes instable which then results in destabilization of axonal microtubules and defects in axonal transport, in particular in motoneurons. Depletion of neurofilament increases the number and regrowth of microtubules in pmn mutant motoneurons and restores axon elongation. This effect is mediated by interaction of neurofilament with the stathmin complex. Accumulating neurofilaments associate with stathmin in axons of pmn mutant motoneurons. Depletion of neurofilament by Nefl knockout increases Stat3-stathmin interaction and stabilizes the microtubules in pmn mutant motoneurons. Consequently, counteracting enhanced neurofilament expression improves axonal maintenance and prolongs survival of pmn mutant mice. We propose that this mechanism could also be relevant for other neurodegenerative diseases in which neurofilament accumulation and loss of microtubules are prominent features. KW - Amyotrophic-lateral-sclerosis KW - Transgenic mice KW - Mouse model KW - Alzheimers disease KW - Neurofilament KW - Progressive motor neuronopathy KW - Axonal transport KW - Intermediate filaments KW - Motoneuron disease KW - Lacking neurofilaments KW - Missense mutation KW - Axon degeneration KW - Microtubules KW - Stathmin KW - Stat3 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188234 VL - 132 IS - 1 ER - TY - JOUR A1 - Weiss, Esther A1 - Schlegel, Jan A1 - Terpitz, Ulrich A1 - Weber, Michael A1 - Linde, Jörg A1 - Schmitt, Anna-Lena A1 - Hünniger, Kerstin A1 - Marischen, Lothar A1 - Gamon, Florian A1 - Bauer, Joachim A1 - Löffler, Claudia A1 - Kurzai, Oliver A1 - Morton, Charles Oliver A1 - Sauer, Markus A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - Reconstituting NK Cells After Allogeneic Stem Cell Transplantation Show Impaired Response to the Fungal Pathogen Aspergillus fumigatus JF - Frontiers in Immunology N2 - Delayed natural killer (NK) cell reconstitution after allogeneic stem cell transplantation (alloSCT) is associated with a higher risk of developing invasive aspergillosis. The interaction of NK cells with the human pathogen Aspergillus (A.) fumigatus is mediated by the fungal recognition receptor CD56, which is relocated to the fungal interface after contact. Blocking of CD56 signaling inhibits the fungal mediated chemokine secretion of MIP-1α, MIP-1β, and RANTES and reduces cell activation, indicating a functional role of CD56 in fungal recognition. We collected peripheral blood from recipients of an allograft at defined time points after alloSCT (day 60, 90, 120, 180). NK cells were isolated, directly challenged with live A. fumigatus germ tubes, and cell function was analyzed and compared to healthy age and gender-matched individuals. After alloSCT, NK cells displayed a higher percentage of CD56\(^{bright}\)CD16\(^{dim}\) cells throughout the time of blood collection. However, CD56 binding and relocalization to the fungal contact side were decreased. We were able to correlate this deficiency to the administration of corticosteroid therapy that further negatively influenced the secretion of MIP-1α, MIP-1β, and RANTES. As a consequence, the treatment of healthy NK cells ex vivo with corticosteroids abrogated chemokine secretion measured by multiplex immunoassay. Furthermore, we analyzed NK cells regarding their actin cytoskeleton by Structured Illumination Microscopy (SIM) and flow cytometry and demonstrate an actin dysfunction of NK cells shown by reduced F-actin content after fungal co-cultivation early after alloSCT. This dysfunction remains until 180 days post-alloSCT, concluding that further actin-dependent cellular processes may be negatively influenced after alloSCT. To investigate the molecular pathomechansism, we compared CD56 receptor mobility on the plasma membrane of healthy and alloSCT primary NK cells by single-molecule tracking. The results were very robust and reproducible between tested conditions which point to a different molecular mechanism and emphasize the importance of proper CD56 mobility. KW - natural killer cell KW - stem cell transplantation KW - corticosteroids KW - CCL3 KW - CCL4 KW - CCL5 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-212581 SN - 1664-3224 VL - 11 ER - TY - JOUR A1 - Rother, Lisa A1 - Kraft, Nadine A1 - Smith, Dylan B. A1 - El Jundi, Basil A1 - Gill, Richard J. A1 - Pfeiffer, Keram T1 - A micro-CT-based standard brain atlas of the bumblebee JF - Cell and Tissue Research N2 - In recent years, bumblebees have become a prominent insect model organism for a variety of biological disciplines, particularly to investigate learning behaviors as well as visual performance. Understanding these behaviors and their underlying neurobiological principles requires a clear understanding of brain anatomy. Furthermore, to be able to compare neuronal branching patterns across individuals, a common framework is required, which has led to the development of 3D standard brain atlases in most of the neurobiological insect model species. Yet, no bumblebee 3D standard brain atlas has been generated. Here we present a brain atlas for the buff-tailed bumblebee Bombus terrestris using micro-computed tomography (micro-CT) scans as a source for the raw data sets, rather than traditional confocal microscopy, to produce the first ever micro-CT-based insect brain atlas. We illustrate the advantages of the micro-CT technique, namely, identical native resolution in the three cardinal planes and 3D structure being better preserved. Our Bombus terrestris brain atlas consists of 30 neuropils reconstructed from ten individual worker bees, with micro-CT allowing us to segment neuropils completely intact, including the lamina, which is a tissue structure often damaged when dissecting for immunolabeling. Our brain atlas can serve as a platform to facilitate future neuroscience studies in bumblebees and illustrates the advantages of micro-CT for specific applications in insect neuroanatomy. KW - neuropils KW - Bombus terrestris KW - insect standard brain atlas KW - iterative shape averaging KW - reconstruction Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267783 SN - 1432-0878 VL - 386 IS - 1 ER - TY - JOUR A1 - Fathy, Moustafa A1 - Darwish, Mostafa A. A1 - Abdelhamid, Al-Shaimaa M. A1 - Alrashedy, Gehad M. A1 - Othman, Othman Ali A1 - Naseem, Muhammad A1 - Dandekar, Thomas A1 - Othman, Eman M. T1 - Kinetin ameliorates cisplatin-induced hepatotoxicity and lymphotoxicity via attenuating oxidative damage, cell apoptosis and inflammation in rats JF - Biomedicines N2 - Though several previous studies reported the in vitro and in vivo antioxidant effect of kinetin (Kn), details on its action in cisplatin-induced toxicity are still scarce. In this study we evaluated, for the first time, the effects of kinetin in cisplatin (cp)- induced liver and lymphocyte toxicity in rats. Wistar male albino rats were divided into nine groups: (i) the control (C), (ii) groups 2,3 and 4, which received 0.25, 0.5 and 1 mg/kg kinetin for 10 days; (iii) the cisplatin (cp) group, which received a single intraperitoneal injection of CP (7.0 mg/kg); and (iv) groups 6, 7, 8 and 9, which received, for 10 days, 0.25, 0.5 and 1 mg/kg kinetin or 200 mg/kg vitamin C, respectively, and Cp on the fourth day. CP-injected rats showed a significant impairment in biochemical, oxidative stress and inflammatory parameters in hepatic tissue and lymphocytes. PCR showed a profound increase in caspase-3, and a significant decline in AKT gene expression. Intriguingly, Kn treatment restored the biochemical, redox status and inflammatory parameters. Hepatic AKT and caspase-3 expression as well as CD95 levels in lymphocytes were also restored. In conclusion, Kn mitigated oxidative imbalance, inflammation and apoptosis in CP-induced liver and lymphocyte toxicity; therefore, it can be considered as a promising therapy. KW - cisplatin KW - hepatotoxicity KW - lymphotoxicity KW - oxidative stress KW - AKT KW - CD95 KW - caspase-3 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281686 SN - 2227-9059 VL - 10 IS - 7 ER - TY - JOUR A1 - Leidinger, Ludwig A1 - Vedder, Daniel A1 - Cabral, Juliano Sarmento T1 - Temporal environmental variation may impose differential selection on both genomic and ecological traits JF - Oikos N2 - The response of populations and species to changing conditions determines how community composition will change functionally, including via trait shifts. Selection from standing variation has been suggested to be more efficient than acquiring new mutations. Yet, studies on community trait composition and trait selection largely focus on phenotypic variation in ecological traits, whereas the underlying genomic traits remain understudied. Using a genome‐explicit, niche‐ and individual‐based model, we address the potential interactions between genomic and ecological traits shaping communities under an environmental selective forcing, namely temporal positively autocorrelated environmental fluctuation. In this model, all ecological traits are explicitly coded by the genome. For our experiments, we initialized 90 replicate communities, each with ca 350 initial species, characterized by random genomic and ecological trait combinations, on a 2D spatially explicit landscape with two orthogonal gradients (temperature and resource use). We exposed each community to two contrasting scenarios: without (i.e. static environments) and with temporal variation. We then analyzed emerging compositions of both genomic and ecological traits at the community, population and genomic levels. Communities in variable environments were species poorer than in static environments, and populations more abundant, whereas genomes had lower genetic linkage, mean genetic variation and a non‐significant tendency towards higher numbers of genes. The surviving genomes (i.e. those selected by variable environments) coded for enhanced environmental tolerance and smaller biomass, which resulted in faster life cycles and thus also in increased potential for evolutionary rescue. Under temporal environmental variation, larger, less linked genomes retained more variation in mean dispersal ability at the population level than at genomic level, whereas the opposite trend emerged for biomass. Our results provide clues to how sexually‐reproducing diploid plant communities might react to variable environments and highlights the importance of genomic traits and their interaction with ecological traits for eco‐evolutionary responses to changing climates. KW - environmental variability KW - genomic traits KW - mechanistic model KW - rapid evolution KW - standing variation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-238945 VL - 130 IS - 7 SP - 1100 EP - 1115 ER - TY - JOUR A1 - Sponsler, Douglas B. A1 - Bratman, Eve Z. T1 - Beekeeping in, of or for the city? A socioecological perspective on urban apiculture JF - People and Nature N2 - The term ‘urban beekeeping’ connotes a host of meanings—sociopolitical, commercial, ecological and personal—beyond the mere description of where bees and beekeepers happen to coincide. Yet, these meanings are seldom articulated explicitly or brought into critical engagement with the relevant fields of urban ecology and political ecology. Beginning with a brief account of the history of urban beekeeping in the United States, we draw upon urban ecological theory to construct a conceptual model of urban beekeeping that distinguishes beekeeping in, of and for the city. In our model, beekeeping in the city describes the mere importation of the traditionally rural practice of beekeeping into urban spaces for the private reasons of the individual beekeeper, whereas beekeeping of the city describes beekeeping that is consciously tailored to the urban context, often accompanied by (semi)professionalization of beekeepers and the formation of local expert communities (i.e. beekeeping associations). Beekeeping for the city describes a shift in mindset in which beekeeping is directed to civic ends beyond the boundaries of the beekeeping community per se. Using this framework, we identify and discuss specific socioecological assets and liabilities of urban beekeeping, and how these relate to beekeeping in, of and for the city. We then formulate actionable guidelines for maturing the practice of urban beekeeping into a beneficent and self‐critical form of urban ecological citizenship; these include fostering self‐regulation within the beekeeping community, harnessing beekeeping as a ‘gateway’ experience for a broader rapprochement between urban residents and nature, and recognizing the political‐ecological context of beekeeping with respect to matters of socioecological justice. KW - environmental justice KW - honey bee KW - multispecies studies KW - policy KW - pollinator KW - urban greening Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239949 VL - 3 IS - 3 SP - 550 EP - 559 ER - TY - JOUR A1 - Kriegel, Peter A1 - Fritze, Michael‐Andreas A1 - Thorn, Simon T1 - Surface temperature and shrub cover drive ground beetle (Coleoptera: Carabidae) assemblages in short‐rotation coppices JF - Agricultural and Forest Entomology N2 - Increasing demand for biomass has led to an on‐going intensification of fuel wood plantations with possible negative effects on open land biodiversity. Hence, ecologists increasingly call for measures that reduce those negative effects on associated biodiversity. However, our knowledge about the efficiency of such measures remains scarce. We investigated the effects of gap implementation in short rotation coppices (SRCs) on carabid diversity and assemblage composition over 3 years, with pitfall traps in gaps, edges and interiors. In parallel, we quantified soil surface temperature, shrub‐ and herb cover. Edges had the highest number of species and abundances per trap, whereas rarefied species richness was significantly lower in short rotation coppice interiors than in other habitat types. Carabid community composition differed significantly between habitat types. The main environmental drivers were temperature for number of species and abundance and shrub cover for rarefied species richness. We found significantly higher rarefied species richness in gaps compared with interiors. Hence, we argue that gap implementation benefits overall diversity in short rotation coppices. Furthermore, the differences in species community composition between habitat types through increased species turnover support carabid diversity in short rotation coppices. These positive effects were largely attributed to microclimate conditions. However, to maintain positive effects, continuous management of herb layer might be necessary. KW - Carabidae KW - fuel wood KW - short‐rotation coppice KW - shrub‐cover KW - temperature Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239873 VL - 23 IS - 4 SP - 400 EP - 410 ER - TY - JOUR A1 - Sieger, Charlotte Sophie A1 - Hovestadt, Thomas T1 - The degree of spatial variation relative to temporal variation influences evolution of dispersal JF - Oikos N2 - In the face of ongoing global climate and land use change, organisms have multiple possibilities to cope with the modification of their environment. The two main possibilities are to either adapt locally or disperse to a more suitable habitat. The evolution of both local adaptation and dispersal interacts and can be influenced by the spatial and temporal variation (of e.g. temperature or precipitation). In an individual based model (IBM), we explore evolution of phenotypes in landscapes with varying degree of spatial relative to global temporal variation in order to examine its influence on the evolution of dispersal, niche optimum and niche width. The relationship between temporal and spatial variation did neither influence the evolution of local adaptation in the niche optimum nor of niche widths. Dispersal probability is highly influenced by the spatio‐temporal relationship: with increasing spatial variation, dispersal probability decreases. Additionally, the shape of the distribution of the trait values over patch attributes switches from hump‐ to U‐shaped. At low spatial variance more individuals emigrate from average habitats, at high spatial variance more from extreme habitats. The comparatively high dispersal probability in extreme patches of landscapes with a high spatial variation can be explained by evolutionary succession of two kinds of adaptive response. Early in the simulations, extreme patches in landscapes with a high spatial variability act as sink habitats, where population persistence depends on highly dispersive individuals with a wide niche. With ongoing evolution, local adaptation of the remaining individuals takes over, but simultaneously a possible bet‐hedging strategy promotes higher dispersal probabilities in those habitats. Here, in generations that experience extreme shifts from the temporal mean of the patch attribute, the expected fitness becomes higher for dispersing individuals than for philopatric individuals. This means that under certain circumstances, both local adaptation and high dispersal probability can be selected for for coping with the projected environmental changes in the future. KW - bet-hedging KW - dispersal KW - ecological niche KW - evolution KW - individual based model KW - spatial variation KW - temporal variation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239049 VL - 129 IS - 11 SP - 1611 EP - 1622 ER - TY - JOUR A1 - Wolf, Matthias T1 - How to teach about what is a species JF - Biology N2 - To ask students what a species is always has something rhetorical about it. Too quickly comes the rote answer, often learned by heart without ever thinking about it: “A species is a reproductive community of populations (reproductively isolated from others), which occupies a specific niche in nature” (Mayr 1982). However, do two people look alike because they are twins or are they twins because they look alike? “Two organisms do not belong to the same species because they mate and reproduce, but they only are able to do so because they belong to the same species” (Mahner and Bunge 1997). Unfortunately, most biology (pre-university) teachers have no opinion on whether species are real or conceptual, simply because they have never been taught the question themselves, but rather one answer they still pass on to their students today, learned by heart without ever thinking about it. Species are either real or conceptual and, in my opinion, it is this “or” that we should teach about. Only then can we discuss those fundamental questions such as who or what is selected, who or what evolves and, finally, what is biodiversity and phylogenetics all about? Individuals related to each other by the tree of life. KW - biospecies KW - species as individuals KW - species as natural kinds KW - species concept KW - species problem Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241052 SN - 2079-7737 VL - 10 IS - 6 ER - TY - JOUR A1 - Kouhestani, Dina A1 - Geis, Maria A1 - Alsouri, Saed A1 - Bumm, Thomas G. P. A1 - Einsele, Hermann A1 - Sauer, Markus A1 - Stuhler, Gernot T1 - Variant signaling topology at the cancer cell–T-cell interface induced by a two-component T-cell engager JF - Cellular & Molecular Immunology N2 - No abstract available. KW - immunotherapy KW - tumour immunology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241189 VL - 18 ER - TY - JOUR A1 - Boff, Samuel A1 - Henrique, Jessica Amaral A1 - Friedel, Anna A1 - Raizer, Josué T1 - Disentangling the path of pollinator attraction in temporarily colored flowers JF - International Journal of Tropical Insect Science N2 - Plants may use different strategies to attract pollinators in long distance (e.g. floral display) and in short distance (e.g. ratio between differentially colored flowers) scales. The Verbenaceae Lantana canescens Kunth is a wide spread species in open sites of the Brazilian Pantanal wetland. Individuals of this generalist species can produce a variable number of open inflorescences with yellow and white flowers that are organized in whorls. In this study we tested the hypothesis that increased floral display (long distance attraction) and the ratio between yellow and white flowers (short distance attraction) enhances the number of pollinator species and individuals. We observed flower visitors and calculated floral parameters in 38 plots of 1 m2 each, that contained a varying number of flowering L. canescens individuals. Non-metric multidimensional scaling and Bray-Curtis distances were used to account for flower visitor composition and the relative visitation rate, respectively. We used a structural equation model to test the power of each predictor variable on the visitation rate and a covariance analysis to disentangle the effect of each independent variable on the frequency of plant-pollinator interactions. We found that the number of flower visitors and the visitation rate increased with increasing number of inflorescences. Disentangling long and short distance attraction indicated that the number of inflorescences (per plot) and the number of yellow flowers (yellowing effect) contributed most to flower visitation at long and short distance, respectively. KW - floral display KW - lantana canescens KW - pantanal wetland KW - honey bees KW - neotropical region KW - pollinator attraction Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235402 VL - 41 ER - TY - JOUR A1 - Hutin, Stephanie A1 - Ling, Wai Li A1 - Tarbouriech, Nicolas A1 - Schoehn, Guy A1 - Grimm, Clemens A1 - Fischer, Utz A1 - Burmeister, Wim P. T1 - The vaccinia virus DNA helicase structure from combined single-particle cryo-electron microscopy and AlphaFold2 prediction JF - Viruses N2 - Poxviruses are large DNA viruses with a linear double-stranded DNA genome circularized at the extremities. The helicase-primase D5, composed of six identical 90 kDa subunits, is required for DNA replication. D5 consists of a primase fragment flexibly attached to the hexameric C-terminal polypeptide (res. 323–785) with confirmed nucleotide hydrolase and DNA-binding activity but an elusive helicase activity. We determined its structure by single-particle cryo-electron microscopy. It displays an AAA+ helicase core flanked by N- and C-terminal domains. Model building was greatly helped by the predicted structure of D5 using AlphaFold2. The 3.9 Å structure of the N-terminal domain forms a well-defined tight ring while the resolution decreases towards the C-terminus, still allowing the fit of the predicted structure. The N-terminal domain is partially present in papillomavirus E1 and polyomavirus LTA helicases, as well as in a bacteriophage NrS-1 helicase domain, which is also closely related to the AAA+ helicase domain of D5. Using the Pfam domain database, a D5_N domain followed by DUF5906 and Pox_D5 domains could be assigned to the cryo-EM structure, providing the first 3D structures for D5_N and Pox_D5 domains. The same domain organization has been identified in a family of putative helicases from large DNA viruses, bacteriophages, and selfish DNA elements. KW - DNA replication KW - helicase KW - Pfam domain KW - poxvirus KW - cryo-electron microscopy KW - structure prediction KW - SF3 helicase KW - orthopoxvirus KW - DNA helicase Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290523 SN - 1999-4915 VL - 14 IS - 10 ER - TY - JOUR A1 - Mehmood, Rashid A1 - Alsaleh, Alanoud A1 - Want, Muzamil Y. A1 - Ahmad, Ijaz A1 - Siraj, Sami A1 - Ishtiaq, Muhammad A1 - Alshehri, Faizah A. A1 - Naseem, Muhammad A1 - Yasuhara, Noriko T1 - Integrative molecular analysis of DNA methylation dynamics unveils molecules with prognostic potential in breast cancer JF - BioMedInformatics N2 - DNA methylation acts as a major epigenetic modification in mammals, characterized by the transfer of a methyl group to a cytosine. DNA methylation plays a pivotal role in regulating normal development, and misregulation in cells leads to an abnormal phenotype as is seen in several cancers. Any mutations or expression anomalies of genes encoding regulators of DNA methylation may lead to abnormal expression of critical molecules. A comprehensive genomic study encompassing all the genes related to DNA methylation regulation in relation to breast cancer is lacking. We used genomic and transcriptomic datasets from the Cancer Genome Atlas (TGCA) Pan-Cancer Atlas, Genotype-Tissue Expression (GTEx) and microarray platforms and conducted in silico analysis of all the genes related to DNA methylation with respect to writing, reading and erasing this epigenetic mark. Analysis of mutations was conducted using cBioportal, while Xena and KMPlot were utilized for expression changes and patient survival, respectively. Our study identified multiple mutations in the genes encoding regulators of DNA methylation. The expression profiling of these showed significant differences between normal and disease tissues. Moreover, deregulated expression of some of the genes, namely DNMT3B, MBD1, MBD6, BAZ2B, ZBTB38, KLF4, TET2 and TDG, was correlated with patient prognosis. The current study, to our best knowledge, is the first to provide a comprehensive molecular and genetic profile of DNA methylation machinery genes in breast cancer and identifies DNA methylation machinery as an important determinant of the disease progression. The findings of this study will advance our understanding of the etiology of the disease and may serve to identify alternative targets for novel therapeutic strategies in cancer. KW - DNA methylation KW - epigenetic modification KW - breast cancer KW - genomics KW - in silico analysis Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-321171 SN - 2673-7426 VL - 3 IS - 2 SP - 434 EP - 445 ER - TY - JOUR A1 - Geiger, Nina A1 - Kersting, Louise A1 - Schlegel, Jan A1 - Stelz, Linda A1 - Fähr, Sofie A1 - Diesendorf, Viktoria A1 - Roll, Valeria A1 - Sostmann, Marie A1 - König, Eva-Maria A1 - Reinhard, Sebastian A1 - Brenner, Daniela A1 - Schneider-Schaulies, Sibylle A1 - Sauer, Markus A1 - Seibel, Jürgen A1 - Bodem, Jochen T1 - The acid ceramidase is a SARS-CoV-2 host factor JF - Cells N2 - SARS-CoV-2 variants such as the delta or omicron variants, with higher transmission rates, accelerated the global COVID-19 pandemic. Thus, novel therapeutic strategies need to be deployed. The inhibition of acid sphingomyelinase (ASM), interfering with viral entry by fluoxetine was reported. Here, we described the acid ceramidase as an additional target of fluoxetine. To discover these effects, we synthesized an ASM-independent fluoxetine derivative, AKS466. High-resolution SARS-CoV-2–RNA FISH and RTqPCR analyses demonstrate that AKS466 down-regulates viral gene expression. It is shown that SARS-CoV-2 deacidifies the lysosomal pH using the ORF3 protein. However, treatment with AKS488 or fluoxetine lowers the lysosomal pH. Our biochemical results show that AKS466 localizes to the endo-lysosomal replication compartments of infected cells, and demonstrate the enrichment of the viral genomic, minus-stranded RNA and mRNAs there. Both fluoxetine and AKS466 inhibit the acid ceramidase activity, cause endo-lysosomal ceramide elevation, and interfere with viral replication. Furthermore, Ceranib-2, a specific acid ceramidase inhibitor, reduces SARS-CoV-2 replication and, most importantly, the exogenous supplementation of C6-ceramide interferes with viral replication. These results support the hypotheses that the acid ceramidase is a SARS-CoV-2 host factor. KW - SARS-CoV-2 KW - ceramides KW - ceramidase KW - fluoxetine KW - acid sphingomyelinase Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286105 SN - 2073-4409 VL - 11 IS - 16 ER - TY - JOUR A1 - Floren, Andreas A1 - Linsenmair, Karl Eduard A1 - Müller, Tobias T1 - Diversity and functional relevance of canopy arthropods in Central Europe JF - Diversity N2 - Although much is known about the ecology and functional importance of canopy arthropods in temperate forests, few studies have tried to assess the overall diversity and investigate the composition and dynamics of tree-specific communities. This has impeded a deeper understanding of the functioning of forests, and of how to maintain system services. Here, we present the first comprehensive data of whole arthropod communities, collected by insecticidal knockdown (fogging) from 1159 trees in 18 study areas in Central Europe during the last 25 years. The data includes 3,253,591 arthropods from 32 taxa (order, suborder, family) collected on 24 tree species from 18 genera. Fogging collects free-living, ectophytic arthropods in approximately the same number as they occur in the trees. To our knowledge, these are the most comprehensive data available today on the taxonomic composition of arboreal fauna. Assigning all arthropods to their feeding guild provided a proxy of their functional importance. The data showed that the canopy communities were regularly structured, with a clear dominance hierarchy comprised of eight ‘major taxa’ that represented 87% of all arthropods. Despite significant differences in the proportions of taxa on deciduous and coniferous trees, the composition of the guilds was very similar. The individual tree genera, on the other hand, showed significant differences in guild composition, especially when different study areas and years were compared, whereas tree-specific traits, such as tree height, girth in breast height or leaf cover, explained little of the overall variance. On the ordinal level, guild composition also differed significantly between managed and primary forests, with a simultaneous low within-group variability, indicating that management is a key factor determining the distribution of biodiversity and guild composition. KW - temperate forests KW - insecticidal knockdown KW - community structure KW - functional diversity KW - guild constancy KW - forest management KW - pristine forests KW - Bialowieza Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285924 SN - 1424-2818 VL - 14 IS - 8 ER - TY - JOUR A1 - Rohmer, Carina A1 - Dobritz, Ronja A1 - Tuncbilek-Dere, Dilek A1 - Lehmann, Esther A1 - Gerlach, David A1 - George, Shilpa Elizabeth A1 - Bae, Taeok A1 - Nieselt, Kay A1 - Wolz, Christiane T1 - Influence of Staphylococcus aureus strain background on Sa3int phage life cycle switches JF - Viruses N2 - Staphylococcus aureus asymptomatically colonizes the nasal cavity of mammals, but it is also a leading cause of life-threatening infections. Most human nasal isolates carry Sa3 phages, which integrate into the bacterial hlb gene encoding a sphingomyelinase. The virulence factor-encoding genes carried by the Sa3-phages are highly human-specific, and most animal strains are Sa3 negative. Thus, both insertion and excision of the prophage could potentially confer a fitness advantage to S. aureus. Here, we analyzed the phage life cycle of two Sa3 phages, Φ13 and ΦN315, in different phage-cured S. aureus strains. Based on phage transfer experiments, strains could be classified into low (8325-4, SH1000, and USA300c) and high (MW2c and Newman-c) transfer strains. High-transfer strains promoted the replication of phages, whereas phage adsorption, integration, excision, or recA transcription was not significantly different between strains. RNASeq analyses of replication-deficient lysogens revealed no strain-specific differences in the CI/Mor regulatory switch. However, lytic genes were significantly upregulated in the high transfer strain MW2c Φ13 compared to strain 8325-4 Φ13. By transcriptional start site prediction, new promoter regions within the lytic modules were identified, which are likely targeted by specific host factors. Such host-phage interaction probably accounts for the strain-specific differences in phage replication and transfer frequency. Thus, the genetic makeup of the host strains may determine the rate of phage mobilization, a feature that might impact the speed at which certain strains can achieve host adaptation. KW - phage KW - virulence KW - induction KW - gene regulation KW - Staphylococcus KW - hemolysin Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297209 SN - 1999-4915 VL - 14 IS - 11 ER - TY - JOUR A1 - Köhler, Franziska A1 - Reese, Lena A1 - Hendricks, Anne A1 - Kastner, Carolin A1 - Müller, Sophie A1 - Lock, Johan F. A1 - Germer, Christoph-Thomas A1 - Wiegering, Armin T1 - Low-grade mucinous neoplasms (LAMN) of the appendix in Germany between 2011 and 2018: a nationwide analysis based on data provided by the German Center for Cancer Registry Data (ZfKD) at the Robert Koch Institute (RKI) JF - Langenbeck’s Archives of Surgery N2 - Introduction Low-grade appendiceal mucinous neoplasms (LAMN) are semi-malignant tumors of the appendix which are incidentally found in up to 1% of appendectomy specimen. To this day, no valid descriptive analysis on LAMN is available for the German population. Methods Data of LAMN (ICD-10: D37.3) were collected from the population-based cancer registries in Germany, provided by the German Center for Cancer Registry Data (Zentrum für Krebsregisterdaten—ZfKD). Data was anonymized and included gender, age at diagnosis, tumor staging according to the TNM-classification, state of residence, information on the performed therapy, and survival data. Results A total of 612 cases were reported to the ZfKD between 2011 and 2018. A total of 63.07% were female and 36.93% were male. Great inhomogeneity in reporting cases was seen in the federal states of Germany including the fact that some federal states did not report any cases at all. Age distribution showed a mean age of 62.03 years (SD 16.15) at diagnosis. However, data on tumor stage was only available in 24.86% of cases (n = 152). A total of 49.34% of these patients presented with a T4-stage. Likewise, information regarding performed therapy was available in the minority of patients: 269 patients received surgery, 22 did not and for 312 cases no information was available. Twenty-four patients received chemotherapy, 188 did not, and for 400 cases, no information was available. Overall 5-year survival was estimated at 79.52%. Patients below the age of 55 years at time of diagnosis had a significantly higher 5-year survival rate compared to patients above the age of 55 years (85.77% vs. 73.27%). Discussion In this study, we observed an incidence of LAMN in 0.13% of all appendectomy specimen in 2018. It seems likely that not all cases were reported to the ZfKD; therefore, case numbers may be considered underestimated. Age and gender distribution goes in line with international studies with females being predominantly affected. Especially regarding tumor stage and therapy in depth information cannot be provided through the ZfKD-database. This data analysis emphasizes the need for further studies and the need for setting up a specialized registry for this unique tumor entity to develop guidelines for the appropriate treatment and follow-up. KW - LAMN KW - low-grade mucinous neoplasm KW - appendix KW - epidemiology KW - ZfKD KW - Germany Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323919 VL - 407 IS - 8 ER - TY - JOUR A1 - Brosch, Philippa K. A1 - Korsa, Tessa A1 - Taban, Danush A1 - Eiring, Patrick A1 - Hildebrand, Sascha A1 - Neubauer, Julia A1 - Zimmermann, Heiko A1 - Sauer, Markus A1 - Shirakashi, Ryo A1 - Djuzenova, Cholpon S. A1 - Sisario, Dmitri A1 - Sukhorukov, Vladimir L. T1 - Glucose and inositol transporters, SLC5A1 and SLC5A3, in glioblastoma cell migration JF - Cancers N2 - (1) Background: The recurrence of glioblastoma multiforme (GBM) is mainly due to invasion of the surrounding brain tissue, where organic solutes, including glucose and inositol, are abundant. Invasive cell migration has been linked to the aberrant expression of transmembrane solute-linked carriers (SLC). Here, we explore the role of glucose (SLC5A1) and inositol transporters (SLC5A3) in GBM cell migration. (2) Methods: Using immunofluorescence microscopy, we visualized the subcellular localization of SLC5A1 and SLC5A3 in two highly motile human GBM cell lines. We also employed wound-healing assays to examine the effect of SLC inhibition on GBM cell migration and examined the chemotactic potential of inositol. (3) Results: While GBM cell migration was significantly increased by extracellular inositol and glucose, it was strongly impaired by SLC transporter inhibition. In the GBM cell monolayers, both SLCs were exclusively detected in the migrating cells at the monolayer edge. In single GBM cells, both transporters were primarily localized at the leading edge of the lamellipodium. Interestingly, in GBM cells migrating via blebbing, SLC5A1 and SLC5A3 were predominantly detected in nascent and mature blebs, respectively. (4) Conclusion: We provide several lines of evidence for the involvement of SLC5A1 and SLC5A3 in GBM cell migration, thereby complementing the migration-associated transportome. Our findings suggest that SLC inhibition is a promising approach to GBM treatment. KW - volume regulation KW - transportome KW - phlorizin Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297498 SN - 2072-6694 VL - 14 IS - 23 ER - TY - THES A1 - Schmalz, Fabian Dominik T1 - Processing of behaviorally relevant stimuli at different levels in the bee brain T1 - Die Verarbeitung verhaltensrelevanter Stimuli auf unterschiedlichen Ebenen im Bienengehirn N2 - The behavior of honeybees and bumblebees relies on a constant sensory integration of abiotic or biotic stimuli. As eusocial insects, a sophisticated intraspecific communication as well as the processing of multisensory cues during foraging is of utter importance. To tackle the arising challenges, both honeybees and bumblebees have evolved a sophisticated olfactory and visual processing system. In both organisms, olfactory reception starts at the antennae, where olfactory sensilla cover the antennal surface in a sex-specific manner. These sensilla house olfactory receptor neurons (ORN) that express olfactory receptors. ORNs send their axons via four tracts to the antennal lobe (AL), the prime olfactory processing center in the bee brain. Here, ORNs specifically innervate spheroidal structures, so-called glomeruli, in which they form synapses with local interneurons and projection neurons (PN). PNs subsequently project the olfactory information via two distinct tracts, the medial and the lateral antennal-lobe tract, to the mushroom body (MB), the main center of sensory integration and memory formation. In the honeybee calyx, the sensory input region of the MB, PNs synapse on Kenyon cells (KC), the principal neuron type of the MB. Olfactory PNs mainly innervate the lip and basal ring layer of the calyx. In addition, the basal ring receives input from visual PNs, making it the first site of integration of visual and olfactory information. Visual PNs, carrying sensory information from the optic lobes, send their terminals not only to the to the basal ring compartment but also to the collar of the calyx. Receiving olfactory or visual input, KCs send their axons along the MB peduncle and terminate in the main output regions of the MB, the medial and the vertical lobe (VL) in a layer-specific manner. In the MB lobes, KCs synapse onto mushroom body output neurons (MBON). In so far barely understood processes, multimodal information is integrated by the MBONs and then relayed further into the protocerebral lobes, the contralateral brain hemisphere, or the central brain among others. This dissertation comprises a dichotomous structure that (i) aims to gain more insight into the olfactory processing in bumblebees and (ii) sets out to broaden our understanding of visual processing in honeybee MBONs. The first manuscript examines the olfactory processing of Bombus terrestris and specifically investigates sex-specific differences. We used behavioral (absolute conditioning) and electrophysiological approaches to elaborate the processing of ecologically relevant odors (components of plant odors and pheromones) at three distinct levels, in the periphery, in the AL and during olfactory conditioning. We found both sexes to form robust memories after absolute conditioning and to generalize towards the carbon chain length of the presented odors. On the contrary, electroantennographic (EAG) activity showed distinct stimulus and sex-specific activity, e.g. reduced activity towards citronellol in drones. Interestingly, extracellular multi-unit recordings in the AL confirmed stimulus and sex-specific differences in olfactory processing, but did not reflect the differences previously found in the EAG. Here, farnesol and 2,3-dihydrofarnesol, components of sex-specific pheromones, show a distinct representation, especially in workers, corroborating the results of a previous study. This explicitly different representation suggests that the peripheral stimulus representation is an imperfect indication for neuronal representation in high-order neuropils and ecological importance of a specific odor. The second manuscript investigates MBONs in honeybees to gain more insights into visual processing in the VL. Honeybee MBONs can be categorized into visually responsive, olfactory responsive and multimodal. To clarify which visual features are represented at this high-order integration center, we used extracellular multi-unit recordings in combination with visual and olfactory stimulation. We show for the first time that information about brightness and wavelength is preserved in the VL. Furthermore, we defined three specific classes of visual MBONs that distinctly encode the intensity, identity or simply the onset of a stimulus. The identity-subgroup exhibits a specific tuning towards UV light. These results support the view of the MB as the center of multimodal integration that categorizes sensory input and subsequently channels this information into specific MBON populations. Finally, I discuss differences between the peripheral representations of stimuli and their distinct processing in high-order neuropils. The unique activity of farnesol in manuscript 1 or the representation of UV light in manuscript 2 suggest that the peripheral representation of a stimulus is insufficient as a sole indicator for its neural activity in subsequent neuropils or its putative behavioral importance. In addition, I discuss the influence of hard-wired concepts or plasticity induced changes in the sensory pathways on the processing of such key stimuli in the peripheral reception as well as in high-order centers like the AL or the MB. The MB as the center of multisensory integration has been broadly examined for its olfactory processing capabilities and receives increasing interest about its visual coding properties. To further unravel its role of sensory integration and to include neglected modalities, future studies need to combine additional approaches and gain more insights on the multimodal aspects in both the input and output region. N2 - Honigbienen und Hummeln sind aufgrund ihrer Lebensweise auf die ständige Verarbeitung sensorischer Eindrücke abiotischen und biotischen Ursprungs angewiesen. Als eusoziale Insekten ist hierbei für beide Arten die Wahrnehmung innerartlicher Kommunikation wie auch die Verarbeitung multisensorischer Einflüsse während der Nahrungssuche von essenzieller Bedeutung. Um die daraus resultierenden vielfältigen Herausforderungen erfolgreich bewältigen zu können, verfügen Honigbienen und Hummeln über eine fortschrittliche Verarbeitung olfaktorischer und visueller Reize. In beiden Arten beginnt die Geruchsrezeption an den Antennen, welche geschlechtsspezifisch von zahlreichen olfaktorischen Sensillen besetzt sind. Diese beinhalten olfaktorische Rezeptorneurone (ORN), in welchen die Expression der Geruchsrezeptoren stattfindet. Axone der ORNs laufen dabei gebündelt über vier verschiedene Trakte in den Antennallobus (AL), das erste olfaktorische Verarbeitungszentrum im Bienengehirn. Im AL verschalten ORNs mit lokalen Interneuronen und Projektionsneuronen (PN) in kugelförmigen Strukturen, den sogenannten Glomeruli. PNs leiten die olfaktorische Information daraufhin über zwei charakteristische Trakte, den medialen und lateralen Antennallobustrakt, in den Pilzkörper (MB), das Verarbeitungszentrum für die Integration sensorischer Eindrücke und Gedächtnisbildung. Im Calyx der Honigbiene, der sensorischen Eingangsregion des MB, bilden die Endköpfchen der PNs synaptische Verbindungen mit Kenyonzellen (KC), den primären Nervenzellen im MB. Die Innervation des Calyx durch die PNs ist dabei spezifisch in drei verschiedenen Zonen organisiert, nämlich in Lippe, Hals und basalen Ring. Während die Lippe vornehmlich olfaktorische Information von PNs aus dem AL erhält, wird der basale Ring zusätzlich auch von visuellen PNs, welche Informationen aus dem optischen Lobus einbringen, angesteuert. Der basale Ring der Honigbiene wird dabei Ort der ersten räumlichen Integration visuellen und olfaktorischen Eingangs. Wiederum ähnlich zum unimodalen Eingang der Lippe, bezieht auch der Hals des Calyx grundsätzlich nur sensorischen Eingang einer Modalität, nämlich visuelle Information von PNs aus dem optischen Lobus. KCs verschalten im weiteren Verlauf die olfaktorischen und visuellen Informationen an Pilzkörperausgangsneurone (MBON). In einem bisher kaum erforschten Vorgang wird diese multimodale Information dabei verarbeitet und dann mithilfe der MBONs in verschiedene Bereiche des Gehirns geleitet, z.B. in die protocerebralen Loben, die kontralaterale Gehirnhemisphäre oder das Zentralgehirn. Diese Dissertation ist zweigeteilt und behandelt zuerst (i) die geschlechtsspezifische Verarbeitung olfaktorischer Reize in Hummeln und bespricht im zweiten Teil (ii) neue Einblicke in die neuronale Weiterverarbeitung visueller Reize durch MBONs in der Honigbiene. Manuskript 1 untersucht die Abläufe der Geruchsverarbeitung von Bombus terrestris und beschreibt geschlechtsspezifische Unterschiede. Hierbei wurden sowohl verhaltensbasierte als auch elektrophysiologische Methoden genutzt um die Wahrnehmung ökologisch relevanter Duftstoffe (Komponenten unterschiedlicher Pflanzendüfte oder Pheromone) auf drei verschiedene Weisen zu untersuchen, nämlich in der Peripherie, im AL und mittels olfaktorischer Konditionierung. Wir fanden in beiden Geschlechtern eine robuste Gedächtnisbildung nach absoluter Konditionierung und eine ausgeprägte Generalisierung anhand der Kohlenstoffkettenlänge der präsentierten Duftstoffe. Anders stellten sich die Ergebnisse der elektroantennographischen (EAG) Untersuchungen dar. Hier zeigten sowohl Drohnen als auch Arbeiterinnen neuronale Aktivität mit spezifischen Unterschieden zwischen den Stimuli, aber auch zwischen den Geschlechtern auf, z.B. löste die Applikation von Citronellol eine deutliche verringerte Reaktion in der EAG Aktivität der Drohnen aus. Interessanterweise zeigten auch extrazelluläre Ableitungen im AL stimulus- und geschlechtsspezifische Unterschiede, jedoch in unterschiedlicher Konstellation als in den EAG-Experimenten. Besonders Farnesol und 2,3-Dihydrofarnesol wiesen vor allem bei Arbeiterinnen eine deutliche Repräsentation in der neuronalen Aktivität auf; ein Alleinstellungsmerkmal welches für Farnesol bereits in einer früheren Studie beschrieben wurde. Diese explizit unterschiedliche neuronale Darstellung von Farnesol und 2,3-Dihydrofarnesol in der Peripherie und im AL führt zu der Annahme, dass die rezeptive Darstellung eines Stimulus in der Peripherie keine zuverlässigen Rückschlüsse über die neuronale Repräsentation in höheren Zentren oder die ökologische Relevanz zulässt. Im zweiten Manuskript stehen MBONs der Honigbiene im Fokus, um mehr Einblicke in die visuelle Verarbeitung im VL zu erlangen. Bisher können MBONs in folgende Klassen unterteilt werden: Visuelle, olfaktorische und multimodale MBONs, welche sensitiv für beide Modalitäten sind. Kern dieser Arbeit ist, mittels extrazellulärer Ableitungen festzustellen, welche zusätzlichen Aspekte eines visuellen Stimulus in diesem zentralen Verarbeitungszentrum repräsentiert sind. Dabei konnte zum ersten Mal gezeigt werden, dass Informationen über die Wellenlänge und die Intensität des Lichtstimulus im VL erhalten sind. Im weiteren Verlauf konnte eine Spezifizierung der bisherigen Kategorisierung visueller und multimodaler MBONs in drei weitere Untergruppen vollzogen werden: MBONs die spezifisch die Intensität, die Identität und dein Eingang eines Stimulus kodieren. Des Weiteren zeigte vor allem die Gruppe der Identitäts-MBONs eine bemerkenswerte Kategorisierung von UV-Licht. Diese neuen Erkenntnisse bestätigen die Ansicht, dass der MB, als Zentrum für sensorische Integration, eine Kategorisierung der verarbeiteten Eindrücke vornimmt und diese daraufhin auf die MBONs verschalten wird. Abschließend diskutiere ich Unterschiede in der peripheren Repräsentation von Stimuli und ihrer späteren neuronalen Verarbeitung. Hier zeige ich, die Aktivität von Farnesol in MS1 und UV-Licht MS2 als Beispiel nehmend, dass die periphere Repräsentation eines Stimulus keine sicheren Schlussfolgerungen über die nachfolgend induzierte neurale Aktivität oder die verhaltensrelevante Bedeutung zulässt. Im weiteren Verlauf werden dabei die Einflüsse konservierter Strukturen und plastischer Änderungen auf die Abläufe der sensorischen Peripherie oder der höheren Verarbeitungszentren, wie dem AL oder dem MB gezeigt. Obwohl der MB, das Zentrum für multimodale Integration und Gedächtnis, hinsichtlich seiner Rolle in der Geruchswahrnehmung ausgiebig erforscht ist, gibt es bezüglich der visuellen Verarbeitung oder dem Einfluss anderer Modalitäten noch ungeklärte Abläufe und Fragen. Wenngleich auch hier die Kenntnis speziell über die visuelle Verarbeitung im MB stetig zunimmt, sollten zukünftige Arbeiten mithilfe weiterer Methoden den MB Eingang und Ausgang explizit auf den Einfluss weiterer Modalitäten untersuchen, um so ein umfassenderes Bild über die Abläufe multimodaler Integration zu erhalten. KW - Biene KW - Elektrophysiologie KW - bee KW - electrophysiology KW - olfaction KW - vision KW - multi-unit recording KW - Olfaktorik KW - Sehen KW - Multi-Unit Aufnahmen Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288824 ER - TY - JOUR A1 - Aupperle-Lellbach, Heike A1 - Heidrich, Daniela A1 - Kehl, Alexandra A1 - Conrad, David A1 - Brockmann, Maria A1 - Törner, Katrin A1 - Beitzinger, Christoph A1 - Müller, Tobias T1 - KITLG copy number germline variations in schnauzer breeds and their relevance in digital squamous cell carcinoma in black giant schnauzers JF - Veterinary Sciences N2 - Copy number variations (CNVs) of the KITLG gene seem to be involved in the oncogenesis of digital squamous cell carcinoma (dSCC). The aims of this study were (1) to investigate KITLG CNV in giant (GS), standard (SS), and miniature (MS) schnauzers and (2) to compare KITLG CNV between black GS with and without dSCC. Blood samples from black GS (22 with and 17 without dSCC), black SS (18 with and 4 without dSSC; 5 unknown), and 50 MS (unknown dSSC status and coat colour) were analysed by digital droplet PCR. The results are that (1) most dogs had a copy number (CN) value > 4 (range 2.5–7.6) with no significant differences between GS, SS, and MS, and (2) the CN value in black GS with dSCC was significantly higher than in those without dSCC (p = 0.02). CN values > 5.8 indicate a significantly increased risk for dSCC, while CN values < 4.7 suggest a reduced risk for dSCC (grey area: 4.7–5.8). Diagnostic testing for KITLG CNV may sensitise owners to the individual risk of their black GS for dSCC. Further studies should investigate the relevance of KITLG CNV in SS and the protective effects in MS, who rarely suffer from dSCC. KW - tumour KW - toe KW - miniature schnauzer KW - standard schnauzer KW - CNV KW - ddPCR KW - breed predisposition Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-303913 SN - 2306-7381 VL - 10 IS - 2 ER - TY - JOUR A1 - de Paz, Víctor A1 - Asís, Josep D. A1 - Holzschuh, Andrea A1 - Baños-Picón, Laura T1 - Effects of traditional orchard abandonment and landscape context on the beneficial arthropod community in a Mediterranean agroecosystem JF - Insects N2 - Agricultural abandonment is one of the main land-use changes in Europe, and its consequences on biodiversity are context- and taxa-dependent. While several studies have worked on this topic, few have focused on traditional orchards, especially in different landscapes and under a Mediterranean climate. In this context, we aimed to determine the effects of almond orchard abandonment on the communities of three groups of beneficial arthropods and the role of the landscape context in modulating these effects. Between February and September 2019, four samplings were carried out in twelve almond orchards (three abandoned and three traditional (active orchards under traditional agricultural management) located in simple landscapes as well as three abandoned and three traditional in complex landscapes). Abandoned and traditional almond orchards harbor different arthropod communities and diversity metrics that are strongly conditioned by seasonality. Abandoned orchards can favor pollinators and natural enemies, providing alternative resources in simple landscapes. However, the role that abandoned orchards play in simple landscapes disappears as the percentage of semi-natural habitats in the landscape increases. Our results show that landscape simplification, through the loss of semi-natural habitats, has negative consequences on arthropod biodiversity, even in traditional farming landscapes with small fields and high crop diversity. KW - abandonment KW - traditional almond orchard KW - spider KW - parasitoid KW - bee KW - landscape complexity Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311190 SN - 2075-4450 VL - 14 IS - 3 ER - TY - JOUR A1 - Wersebeckmann, Vera A1 - Biegerl, Carolin A1 - Leyer, Ilona A1 - Mody, Karsten T1 - Orthopteran diversity in steep slope vineyards: the role of vineyard type and vegetation management JF - Insects N2 - The abandonment of traditional agricultural practices and subsequent succession are major threats to many open-adapted species and species-rich ecosystems. Viticulture on steep slopes has recently suffered from strong declines due to insufficient profitability, thus increasing the area of fallow land considerably. Changing cultivation systems from vertically oriented to modern vineyard terraces offers an opportunity to maintain management economically viable and thus reduces further abandonment. Hillside parallel terraces favor mechanization, and their embankments offer large undisturbed areas that could provide valuable habitats. We investigated the effects of vineyard abandonment, different vineyard management types (vertically oriented vs. terraced), and local parameters on Orthoptera diversity in 45 study sites along the Upper Middle Rhine Valley in Germany. Our results show that woody structures and vineyard abandonment reduced Orthoptera diversity at the local and landscape scale due to decreased habitat quality, especially for open-adapted species. In contrast, open inter-rows of actively managed vineyard types supported heat-adapted Caelifera species. On terrace embankments, extensive management and taller vegetation benefited Ensifera species, while short and mulched vegetation in vertically oriented vineyards favored the dominance of one single Caelifera species. Our results highlight the significance of maintaining viticultural management on steep slopes for the preservation of both open-adapted Orthoptera species and the cultural landscape. KW - abandonment KW - alternating management KW - biodiversity conservation KW - grasshopper KW - insect conservation KW - succession KW - traditional land use KW - vineyard terrace Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304891 SN - 2075-4450 VL - 14 IS - 1 ER - TY - JOUR A1 - Dong, Meng A1 - Böpple, Kathrin A1 - Thiel, Julia A1 - Winkler, Bernd A1 - Liang, Chunguang A1 - Schueler, Julia A1 - Davies, Emma J. A1 - Barry, Simon T. A1 - Metsalu, Tauno A1 - Mürdter, Thomas E. A1 - Sauer, Georg A1 - Ott, German A1 - Schwab, Matthias A1 - Aulitzky, Walter E. T1 - Perfusion air culture of precision-cut tumor slices: an ex vivo system to evaluate individual drug response under controlled culture conditions JF - Cells N2 - Precision-cut tumor slices (PCTS) maintain tissue heterogeneity concerning different cell types and preserve the tumor microenvironment (TME). Typically, PCTS are cultured statically on a filter support at an air–liquid interface, which gives rise to intra-slice gradients during culture. To overcome this problem, we developed a perfusion air culture (PAC) system that can provide a continuous and controlled oxygen medium, and drug supply. This makes it an adaptable ex vivo system for evaluating drug responses in a tissue-specific microenvironment. PCTS from mouse xenografts (MCF-7, H1437) and primary human ovarian tumors (primary OV) cultured in the PAC system maintained the morphology, proliferation, and TME for more than 7 days, and no intra-slice gradients were observed. Cultured PCTS were analyzed for DNA damage, apoptosis, and transcriptional biomarkers for the cellular stress response. For the primary OV slices, cisplatin treatment induced a diverse increase in the cleavage of caspase-3 and PD-L1 expression, indicating a heterogeneous response to drug treatment between patients. Immune cells were preserved throughout the culturing period, indicating that immune therapy can be analyzed. The novel PAC system is suitable for assessing individual drug responses and can thus be used as a preclinical model to predict in vivo therapy responses. KW - precision-cut tumor slices KW - perfusion culture KW - tumor microenvironment KW - ovarian tumor KW - individual drug responses KW - mouse xenografts KW - preclinical model KW - personalized medicine Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311030 SN - 2073-4409 VL - 12 IS - 5 ER - TY - JOUR A1 - Cerezo-Echevarria, Argiñe A1 - Kehl, Alexandra A1 - Beitzinger, Christoph A1 - Müller, Tobias A1 - Klopfleisch, Robert A1 - Aupperle-Lellbach, Heike T1 - Evaluating the histologic grade of digital squamous cell carcinomas in dogs and copy number variation of KIT Ligand — a correlation study JF - Veterinary Sciences N2 - Dark-haired dogs are predisposed to the development of digital squamous cell carcinoma (DSCC). This may potentially suggest an underlying genetic predisposition not yet completely elucidated. Some authors have suggested a potential correlation between the number of copies KIT Ligand (KITLG) and the predisposition of dogs to DSCC, containing a higher number of copies in those affected by the neoplasm. In this study, the aim was to evaluate a potential correlation between the number of copies of the KITLG and the histological grade of malignancy in dogs with DSCC. For this, 72 paraffin-embedded DSCCs with paired whole blood samples of 70 different dogs were included and grouped according to their haircoat color as follow: Group 0/unknown haircoat color (n = 11); Group 1.a/black non-Schnauzers (n = 15); group 1.b/black Schnauzers (n = 33); group 1.c/black and tan dogs (n = 7); group 2/tan animals (n = 4). The DSCCs were histologically graded. Additionally, KITLG Copy Number Variation (CNV) was determined by ddPCR. A significant correlation was observed between KITLG copy number and the histological grade and score value. This finding may suggest a possible factor for the development of canine DSCC, thus potentially having an impact on personalized veterinary oncological strategies and breeding programs. KW - canine KW - cancer KW - toe KW - grading KW - haircoat KW - color KW - genetics KW - gene Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304824 SN - 2306-7381 VL - 10 IS - 2 ER - TY - THES A1 - Reuter, Christian Steffen T1 - Development of a tissue-engineered primary human skin infection model to study the pathogenesis of tsetse fly-transmitted African trypanosomes in mammalian skin T1 - Entwicklung eines primären humanen Hautinfektionsmodells basierend auf Gewebezüchtung zur Erforschung der Pathogenese von Tsetsefliegen-übertragenen Afrikanischen Trypanosomen in der Säugetierhaut N2 - Many arthropods such as mosquitoes, ticks, bugs, and flies are vectors for the transmission of pathogenic parasites, bacteria, and viruses. Among these, the unicellular parasite Trypanosoma brucei (T. brucei) causes human and animal African trypanosomiases and is transmitted to the vertebrate host by the tsetse fly. In the fly, the parasite goes through a complex developmental cycle in the alimentary tract and salivary glands ending with the cellular differentiation into the metacyclic life cycle stage. An infection in the mammalian host begins when the fly takes a bloodmeal, thereby depositing the metacyclic form into the dermal skin layer. Within the dermis, the cell cycle-arrested metacyclic forms are activated, re-enter the cell cycle, and differentiate into proliferative trypanosomes, prior to dissemination throughout the host. Although T. brucei has been studied for decades, very little is known about the early events in the skin prior to systemic dissemination. The precise timing and the mechanisms controlling differentiation of the parasite in the skin continue to be elusive, as does the characterization of the proliferative skin-residing trypanosomes. Understanding the first steps of an infection is crucial for developing novel strategies to prevent disease establishment and its progression. A major shortcoming in the study of human African trypanosomiasis is the lack of suitable infection models that authentically mimic disease progression. In addition, the production of infectious metacyclic parasites requires tsetse flies, which are challenging to keep. Thus, although animal models - typically murine - have produced many insights into the pathogenicity of trypanosomes in the mammalian host, they were usually infected by needle injection into the peritoneal cavity or tail vein, bypassing the skin as the first entry point. Furthermore, animal models are not always predictive for the infection outcome in human patients. In addition, the relatively small number of metacyclic parasites deposited by the tsetse flies makes them difficult to trace, isolate, and study in animal hosts. The focus of this thesis was to develop and validate a reconstructed human skin equivalent as an infection model to study the development of naturally-transmitted metacyclic parasites of T. brucei in mammalian skin. The first part of this work describes the development and characterization of a primary human skin equivalent with improved mechanical properties. To achieve this, a computer-assisted compression system was designed and established. This system allowed the improvement of the mechanical stability of twelve collagen-based dermal equivalents in parallel through plastic compression, as evaluated by rheology. The improved dermal equivalents provided the basis for the generation of the skin equivalents and reduced their contraction and weight loss during tissue formation, achieving a high degree of standardization and reproducibility. The skin equivalents were characterized using immunohistochemical and histological techniques and recapitulated key anatomical, cellular, and functional aspects of native human skin. Furthermore, their cellular heterogeneity was examined using single-cell RNA sequencing - an approach which led to the identification of a remarkable repertoire of extracellular matrix-associated genes expressed by different cell subpopulations in the artificial skin. In addition, experimental conditions were established to allow tsetse flies to naturally infect the skin equivalents with trypanosomes. In the second part of the project, the development of the trypanosomes in the artificial skin was investigated in detail. This included the establishment of methods to successfully isolate skin-dwelling trypanosomes to determine their protein synthesis rate, cell cycle and metabolic status, morphology, and transcriptome. Microscopy techniques to study trypanosome motility and migration in the skin were also optimized. Upon deposition in the artificial skin by feeding tsetse, the metacyclic parasites were rapidly activated and established a proliferative population within one day. This process was accompanied by: (I) reactivation of protein synthesis; (II) re-entry into the cell cycle; (III) change in morphology; (IV) increased motility. Furthermore, these observations were linked to potentially underlying developmental mechanisms by applying single-cell parasite RNA sequencing at five different timepoints post-infection. After the initial proliferative phase, the tsetse-transmitted trypanosomes appeared to enter a reversible quiescence program in the skin. These quiescent skin-residing trypanosomes were characterized by very slow replication, a strongly reduced metabolism, and a transcriptome markedly different from that of the deposited metacyclic forms and the early proliferative trypanosomes. By mimicking the migration from the skin to the bloodstream, the quiescent phenotype could be reversed and the parasites returned to an active proliferating state. Given that previous work has identified the skin as an anatomical reservoir for T. brucei during disease, it is reasonable to assume that the quiescence program is an authentic facet of the parasite's behavior in an infected host. In summary, this work demonstrates that primary human skin equivalents offer a new and promising way to study vector-borne parasites under close-to-natural conditions as an alternative to animal experimentation. By choosing the natural transmission route - the bite of an infected tsetse fly - the early events of trypanosome infection have been detailed with unprecedented resolution. In addition, the evidence here for a quiescent, skin-residing trypanosome population may explain the persistence of T. brucei in the skin of aparasitemic and asymptomatic individuals. This could play an important role in maintaining an infection over long time periods. N2 - Zahlreiche Arthropoden wie Stechmücken, Zecken, Wanzen und Fliegen sind Überträger für krankheitserregende Parasiten, Bakterien und Viren. Hierzu gehört der einzellige Parasit Trypanosoma brucei (T. brucei), welcher durch Tsetsefliegen übertragen wird und die Afrikanische Trypanosomiasis bei Menschen und Tieren verursacht. Der Entwicklungszyklus des Parasiten in der Fliege ist komplex und endet in der Speicheldrüse mit der Differenzierung in das metazyklische Lebensstadium. Diese metazyklischen Formen werden durch den Biss der blutsaugenden Tsetsefliege in die dermale Hautschicht des Säugetierwirts injiziert. Die zellzyklusarretierten metazyklischen Formen werden in der Dermis aktiviert und der Widereintritt in den Zellzyklus sowie die Differenzierung zu proliferativen Trypanosomen eingeleitet. Anschließend breitet sich der Parasit systemisch im Säugetierwirt aus. Obwohl T. brucei bereits seit Jahrzehnten erforscht wird, ist nur sehr wenig über das frühe Infektionsgeschehen in der Haut bekannt. Der genaue Zeitpunkt und die Mechanismen, die der Differenzierung des Parasiten in der Haut zugrunde liegen, sind unbekannt. Ebenso wurden die proliferativen Trypanosomen in der Haut bisher nur unzureichend charakterisiert. Das Verständnis über die ersten Schritte einer Infektion ist jedoch von entscheidender Bedeutung für die Entwicklung von neuen Strategien, die die Krankheitsentstehung und deren Fortschreiten verhindern sollen. Ein großes Hindernis bei der Erforschung der humanen Afrikanischen Trypanosomiasis ist der Mangel an geeigneten Infektionsmodellen, die den Krankheitsverlauf authentisch nachbilden. Außerdem werden für die Erzeugung der infektiösen metazyklischen Parasiten Tsetsefliegen benötigt, die aufwändig zu züchten sind. Tiermodelle haben es ermöglicht - hauptsächlich Mäuse -, viele Erkenntnisse über die Pathogenese von Trypanosomen im Säugetierwirt zu erlangen. Allerdings wurden diese überwiegend durch Nadelinjektion in den Bauchraum oder die Kaudalvene infiziert, wodurch die Haut als erste Eintrittspforte umgangen wurde. Darüber hinaus lassen Tiermodelle nicht immer Rückschlüsse auf den Infektionsverlauf beim Menschen zu. Zusätzlich erschwert die geringe Anzahl von metazyklischen Parasiten, die von Tsetsefliegen injiziert werden, die Isolation, Nachweis und Untersuchung im tierischen Wirt. Das Ziel der vorliegenden Arbeit war es, ein rekonstruiertes menschliches Hautäquivalent zu entwickeln und als Infektionsmodell zu validieren, um die Entwicklung von natürlich übertragenen metazyklischen Parasiten von T. brucei in der Säugetierhaut zu untersuchen. Der erste Teil dieser Arbeit beschreibt die Entwicklung und Charakterisierung eines primären menschlichen Hautäquivalents mit verbesserten mechanischen Eigenschaften. Zu diesem Zweck wurde ein computergesteuertes Kompressionssystem entworfen und hergestellt. Dieses System ermöglichte die gleichzeitige Verbesserung der mechanischen Stabilität von zwölf kollagenbasierten dermalen Äquivalenten durch plastische Kompression, die mittels Rheologie evaluiert wurden. Die verbesserten dermalen Äquivalente dienten als Fundament für die Erzeugung der Hautäquivalente und reduzierten deren Kontraktion und Gewichtsverlust während der Gewebebildung. Dadurch wurde ein hohes Maß an Standardisierung und Reproduzierbarkeit erreicht. Die Hautäquivalente wurden durch immunhistochemische und histologische Techniken charakterisiert und bildeten wichtige anatomische, zelluläre und funktionelle Aspekte der nativen menschlichen Haut nach. Des Weiteren wurde die zelluläre Heterogenität durch Einzelzell-RNA-Sequenzierung untersucht. Mit dieser Technik wurde ein umfangreiches Spektrum an extrazellulären Matrix-assoziierten Genen identifiziert, die von verschiedenen Zellsubpopulationen in der künstlichen Haut exprimiert werden. Zusätzlich wurden experimentelle Bedingungen etabliert, damit Tsetsefliegen eingesetzt werden konnten, um die Hautäquivalente auf natürlichem Weg mit Trypanosomen zu infizieren. Im zweiten Teil dieser Arbeit wurde die Entwicklung der Trypanosomen in der künstlichen Haut im Detail untersucht. Dies umfasste die Etablierung von Methoden zur erfolgreichen Isolierung der Trypanosomen aus der Haut, um deren Proteinsyntheserate, Zellzyklus- und Stoffwechselstatus, sowie Morphologie und Transkriptom zu bestimmen. Zusätzlich wurden Mikroskopietechniken zur Untersuchung der Trypanosomenmotilität und migration in der Haut optimiert. Nach der Injektion in die künstliche Haut durch Tsetsefliegen wurden die metazyklischen Parasiten schnell aktiviert und etablierten innerhalb eines Tages eine proliferative Population. Dieser Entwicklungsprozess wurde begleitet von (I) einer Reaktivierung der Proteinsynthese, (II) einem Wiedereintritt in den Zellzyklus, (III) einer Veränderung der Morphologie und (IV) einer erhöhten Motilität. Des Weiteren wurden diese Beobachtungen mit potentiell zugrundeliegenden entwicklungsbiologischen Mechanismen in Verbindung gebracht, indem eine Einzelzell RNA-Sequenzierung der Trypanosomen zu fünf verschiedenen Zeitpunkten nach der Infektion durchgeführt wurde. Nach der ersten proliferativen Phase traten die Tsetse-übertragenen Trypanosomen in der Haut in ein reversibles Ruhestadium ein. Diese ruhenden Trypanosomen waren durch eine sehr langsame Zellteilung, einen stark reduzierten Stoffwechsel und ein Transkriptom gekennzeichnet, dass sich deutlich von dem der injizierten metazyklischen Formen und der ersten proliferativen Trypanosomen unterschied. Durch Nachahmung der Migration von der Haut in den Blutkreislauf konnte dieser Phänotyp reaktiviert werden und die Parasiten kehrten in einen aktiven, proliferierenden Zustand zurück. Unter Berücksichtigung, dass vorangegangene Forschungsarbeiten die Haut als anatomisches Reservoir für T. brucei während des Krankheitsverlaufs identifiziert haben, ist anzunehmen, dass das Ruheprogramm eine authentische Facette im Verhalten des Parasiten in einem infizierten Wirt darstellt. Zusammenfassend zeigt diese Arbeit, das primäre menschliche Hautäquivalente eine neue und vielversprechende Möglichkeit bieten, vektorübertragene Parasiten unter naturnahen Bedingungen als Alternative zu Tierversuchen zu untersuchen. Durch die Verwendung des natürlichen Infektionsweges - dem Biss einer infizierten Tsetsefliege -, konnten die frühen Prozesse einer Trypanosomen-Infektion mit noch nie dagewesener Detailtiefe nachvollzogen werden. Des Weiteren könnte der hier erbrachte Nachweis einer ruhenden, hautresidenten Trypanosomen-Population die Persistenz von T. brucei in der Haut von aparasitämischen und asymptomatischen Personen erklären. Dies könnte eine wichtige Rolle bei der Aufrechterhaltung einer Infektion über lange Zeiträume spielen. KW - Trypanosoma brucei KW - Tissue Engineering KW - Trypanosomiasis KW - 3D-Zellkultur KW - Transkriptomanalyse KW - developmental differentiation KW - skin equivalent KW - artificial human skin KW - single-cell RNA sequencing KW - quiescence Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-251147 ER - TY - JOUR A1 - Dhillon, Maninder Singh A1 - Kübert-Flock, Carina A1 - Dahms, Thorsten A1 - Rummler, Thomas A1 - Arnault, Joel A1 - Steffan-Dewenter, Ingolf A1 - Ullmann, Tobias T1 - Evaluation of MODIS, Landsat 8 and Sentinel-2 data for accurate crop yield predictions: a case study using STARFM NDVI in Bavaria, Germany JF - Remote Sensing N2 - The increasing availability and variety of global satellite products and the rapid development of new algorithms has provided great potential to generate a new level of data with different spatial, temporal, and spectral resolutions. However, the ability of these synthetic spatiotemporal datasets to accurately map and monitor our planet on a field or regional scale remains underexplored. This study aimed to support future research efforts in estimating crop yields by identifying the optimal spatial (10 m, 30 m, or 250 m) and temporal (8 or 16 days) resolutions on a regional scale. The current study explored and discussed the suitability of four different synthetic (Landsat (L)-MOD13Q1 (30 m, 8 and 16 days) and Sentinel-2 (S)-MOD13Q1 (10 m, 8 and 16 days)) and two real (MOD13Q1 (250 m, 8 and 16 days)) NDVI products combined separately to two widely used crop growth models (CGMs) (World Food Studies (WOFOST), and the semi-empiric Light Use Efficiency approach (LUE)) for winter wheat (WW) and oil seed rape (OSR) yield forecasts in Bavaria (70,550 km\(^2\)) for the year 2019. For WW and OSR, the synthetic products’ high spatial and temporal resolution resulted in higher yield accuracies using LUE and WOFOST. The observations of high temporal resolution (8-day) products of both S-MOD13Q1 and L-MOD13Q1 played a significant role in accurately measuring the yield of WW and OSR. For example, L- and S-MOD13Q1 resulted in an R\(^2\) = 0.82 and 0.85, RMSE = 5.46 and 5.01 dt/ha for WW, R\(^2\) = 0.89 and 0.82, and RMSE = 2.23 and 2.11 dt/ha for OSR using the LUE model, respectively. Similarly, for the 8- and 16-day products, the simple LUE model (R\(^2\) = 0.77 and relative RMSE (RRMSE) = 8.17%) required fewer input parameters to simulate crop yield and was highly accurate, reliable, and more precise than the complex WOFOST model (R\(^2\) = 0.66 and RRMSE = 11.35%) with higher input parameters. Conclusively, both S-MOD13Q1 and L-MOD13Q1, in combination with LUE, were more prominent for predicting crop yields on a regional scale than the 16-day products; however, L-MOD13Q1 was advantageous for generating and exploring the long-term yield time series due to the availability of Landsat data since 1982, with a maximum resolution of 30 m. In addition, this study recommended the further use of its findings for implementing and validating the long-term crop yield time series in different regions of the world. KW - MODIS KW - Sentinel-2 KW - Landsat 8 KW - sustainable agriculture KW - decision-making KW - winter wheat KW - oil seed rape KW - resolution Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311132 SN - 2072-4292 VL - 15 IS - 7 ER - TY - THES A1 - Gotthard, Hannes T1 - Targeting Colorectal Cancer Stem Cells with Hemibodies T1 - Eliminierung von Krebsstammzellen des kolorektalen Karzinoms mithilfe von Hemibodies N2 - The cancer stem cell hypothesis is a cancer development model which elicited great interest in the last decades stating that cancer heterogeneity arises from a stem cell through asymmetrical division. The Cancer Stem Cell subset is described as the only population to be tumorigenic and having the potential to renew. Conventional therapy often fails to eradicate CSC resulting in tumor relapse. Consequently, it is of great inter-est to eliminate this subset of cells to provide the best patient outcome. In the last years several approaches to target CSC were developed, one of them being immunotherapeu-tic targeting with antibodies. Since markers associated with CSC are also expressed on normal stem cells or healthy adjacent tissue in colorectal cancer, dual targeting strate-gies are preferred over targeting only a single antigen. Subsequently, the idea of dual targeting two CSC markers in parallel by a newly developed split T cell-engaging anti-body format termed as Hemibodies emerged. In a preliminary single cell RNA sequenc-ing analysis of colorectal cancer cells CD133, CD24, CD166 and CEA were identified as suitable targets for the combinatorial targeting strategy. Therefore, this study focused on trispecific and trivalent Hemibodies comprising a split binding moiety against CD3 and a binding moiety against either CD133, CD24, CD166 or CEA to overcome the occurrence of resistance and to efficiently eradicate all tumor cells including the CSC compartment. The study showed that the Hemibody combinations CD133xCD24, CD133xCD166 and CD133xCEA are able to eliminate double positive CHO cells with high efficacy while having a high specificity indicated by no killing of single antigen positive cells. A thera-peutic window ranging between one to two log levels could be achieved for all combina-tions mentioned above. The combinations CD133xCD24 and CD133xCD166 further-more proved its efficacy and specificity on established colorectal cancer cell lines. Be-sides the evaluation of specificity and efficacy the already introduced 1st generation of Hemibodies could be improved into a 2nd generation Hemibody format with increased half-life, stability and production yield. In future experiments the applicability of above-mentioned Hemibodies will be proven on patient-derived micro tumors to also include variables like tumor microenvironment and infiltration. N2 - In den letzten Jahrzenten wurde neben der klonalen Evolution ein weiteres Modell zur Krebsentstehung und dessen Heterogenität entwickelt: die Krebsstammzellhypothe-se. Diese Hypothese besagt, dass die Heterogenität eines Tumors durch asymmetri-sche Teilung von sogenannten Krebsstammzellen entsteht. Nur diese sind tumorigen und in der Lage Metastasen zu bilden. Außerdem werden Krebsstammzellen als re-sistent gegen konventionelle Therapien beschrieben, weshalb es nach einer anfängli-chen Tumorregression oft zu einem Rezidiv durch erneutes Auswachsen von zurück-bleibenden Krebsstammzellen kommt. Deshalb ist es von großem Interesse genau diese Population abzutöten, um eine erfolgreiche Therapie zu gewährleisten. In den letzten Jahren wurden zahlreiche Medikationen entwickelt, um Krebsstammzellen ge-zielt anzugreifen. Ein vielversprechender Ansatz ist hierbei die immuntherapeutische Adressierung mittels Antikörpern gegen Krebsstammzellmarkern. Einzelne Marker sind allerdings auch auf normalen Stammzellen und gesundem Gewebe exprimiert, weshalb Therapien, die auf mindestens zwei verschiedene Oberflächenproteine ab-zielen, erfolgsversprechender sind. In dieser Arbeit wurde ein neues T-Zell rekrutie-rendes Antikörperformat entwickelt, sogenannte Hemibodies. Hierbei handelt es sich um ein trispezifisches und trivalentes Format, bestehend aus jeweils zwei Fragmen-ten. Jedes Fragment besteht aus einer Bindedomäne gegen ein Krebsstammzellmar-ker und einer geteilten Bindedomäne gegen CD3. Durch Bindung beider Fragmente an einen Stammzellmarker kommt es zur Komplementierung der geteilten anti-CD3 Domäne und zur T-Zellrekrutierung. Der erste Teil der Arbeit befasst sich mit der bioin-formatischen Analyse von Einzelzell-RNA-Daten des kolorektalen Karzinoms (KRK) zur Identifizierung von potentiellen Krebsstammzellmarkern. Dabei konnten die Ober-flächenproteine CD24, CD133, CD166 und CEA und besonders deren Kombination als geeignete Zielstrukturen identifiziert werden. Die gegen oben genannte Antigene gerichteten Hemibodies zeigten in den Kombinationen CD133xCD24, CD133xCD166 und CD133xCEA auf doppelt positiven CHO-Zellen eine hohe Effektivität. Außerdem konnte die Spezifität durch ein Ausbleiben von Zelltod auf einzel-positiven CHO Zellen bewiesen werden. Die Kombinationen CD133xCD24 und CD133xCD166 konnten Effektivität und Spezifität auch auf etablierten Krebszellen zeigen. Die oben genann-ten Kombinationen waren in einem therapeutischen Fenster von ein bis zwei Logstu-fen funktional. Neben der Testung verschiedener Hemibody-Kombinationen konnten die bereits publizierten Hemibodies der ersten Generation in ein neues Format der zweiten Generation weiterentwickelt werden. Das neue Format zeigte eine verbesser-te Halbwertszeit, Stabilität und Produzierbarkeit. In zukünftigen Experimenten werden die in der Thesis benutzten Hemibodies auf Mikrotumoren getestet, um weitere Vari-ablen, die die Effektivität und Spezifität beeinflussen zu ermitteln. KW - Monoklonaler bispezifischer Antikörper KW - Antikörper KW - T-Lymphozyt KW - Immunreaktion KW - Dickdarmkrebs KW - Hemibody KW - Hemibodies KW - Colorectal Cancer KW - trispecific KW - T-cell engager KW - dual targeting KW - Bispecific T-cell engager KW - stem cells KW - Kolorektales Karzinom Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-303090 ER - TY - THES A1 - Meiser, Elisabeth T1 - Single-molecule dynamics at a bottleneck: a systematic study of the narrow escape problem in a disc T1 - Einzelmoleküldynamik an einem Engpass: Eine systematische Untersuchung des Narrow Escape Problems in einer Scheibe N2 - Diffusion facilitates numerous reactions within the biological context of a cell. It is remarkable how the cost-efficient random process of Brownian motion promotes fast reactions. From the narrow escape theory, it is possible to determine the mean first passage time of such processes based on their reaction space and diffusion coefficient. The narrow escape theory of Brownian particles is characterized by a confining domain with reflective boundaries and a small reaction site. In this thesis, the mean first passage time was systematically tested in a disc as a function of the escape opening size in vitro and in silico. For the in vitro experiments, a model system of patterned supported-lipid bilayers (SLB) was established. Such a model is prepared by a combined colloid metalization approach, where a gold scaffold on glass facilitates assembly of SLB patches of distinct sizes through vesicle fusion. The model setup was evaluated and found to match all necessary requirements to test the nar- row escape problem in vitro. In particular, the reflectivity of the boundaries, the unhindered, free diffusion of the tracer lipids, and the distinct area were assessed. Observed results of the mean first passage time agreed with the theory of the narrow escape problem. There was excellent agreement in both absolute values and across a range of small escape opening sizes. Additionally, I developed a straightforward method, a correction factor, to calculate the mean first passage time from incomplete experimental traces. By re-scaling the mean first passage time to the fraction of particles that escaped, I was able to overcome the lifetime limitations of fluorescent probes. Previously inaccessible measurements of the mean first passage time relying on fluorescent probes will be made possible through this approach. The in vitro experiments were complemented with various in silico experiments. The latter were based on random walk simulations in discs, mimicking the in vitro situation with its uncertainties. The lifetime of single particles was either set sufficiently long to allow all particles to escape, or was adjusted to meet the lifetime limitations observed in the in vitro experiments. A comparison of the mean first passage time from lifetime-unlimited particles to the corrected, lifetime-limited particles did support the use of the correction factor. In agreement with the narrow escape theory, it was experimentally found that the mean first passage time is independent of the start point of the particle within the domain. This is when the particle adheres to a minimum distance to the escape site. In general, the presented random walk simulations do accurately represent the in vitro experiments in this study. The required hardware for the establishment of an astigmatism-based 3D system was installed in the existing microscope. The first attempts to analyze the obtained 3D imaging data gave insight into the potential of the method to investigate molecule dynamics in living trypanosome cells. The full functionality will be realized with the ongoing improvement of image analysis outside of this thesis. N2 - Diffusion erleichtert zahlreiche Reaktionen im biologischen Kontext einer Zelle. Es ist bemerkenswert, wie der kosteneffiziente Zufallsprozess der Brownschen Bewegung schnelle Reaktionen fördert. Mit Hilfe der Narrow Escape Theorie kann die mittlere erste Durchgangszeit (mean first passage time) solcher Prozesse auf der Grundlage ihres Reaktionsraums und des Diffusionskoeffizienten bestimmt werden. Die Narrow Escape Theorie von Brownschen Teilchen wird durch einen begrenzten Bereich mit reflektierenden Grenzen und einen kleinen Reaktionsraum gekennzeichnet. In dieser Arbeit wurde die mittlere erste Durchgangszeit in einer Scheibe systematisch als Funktion der Größe der Fluchtöffnung in vitro und in silico untersucht. Fur die in vitro-Experimente wurde ein Modellsystem aus strukturierten, Glas gestützten Lipiddoppelschichten (SLB) erstellt. Dieses Modell wurde durch einen kombinierten Kolloid-Metallisierungsansatz hergestellt, bei dem eine strukturierte Goldschicht auf Glas die Bildung von SLB-Scheiben unterschiedlicher Größe durch die Vesikelfusion ermöglicht. Es wurde festgestellt, dass das Modell alle Anforderungen erfüllt, um das Narrow escape problem in vitro zu testen. Insbesondere wurde das Reflexionsvermögen der Grenzen, die ungehinderte, freie Diffusion der Lipide und die Präzision der Fläche bewertet. Die beobachteten Ergebnisse der mittleren ersten Durchgangszeit stimmen mit der NEP-Theorie ̈uberein. Es besteht eine hervorragende ̈Ubereinstimmung sowohl bei den absoluten Werten als auch systematisch ̈uber einen Bereich von kleinen Fluchtöffnungsgrößen. Außerdem zeige ich eine einfache Methode, einen Korrekturfaktor, zur Berechnung der mittleren ersten Durchgangszeit aus unvollstandigen Lipid Trajektorien des Experimentes. Indem ich die mittlere erste Durchgangszeit auf den Anteil der entkommenen Par- tikel skalierte, konnte ich die Einschränkungen der Lebensdauer von fluoreszenten Farbstoffen ausgleichen. Mit dieser Technik werden bisher unzugängliche Messungen der mittleren ersten Durchgangszeit auf der Grundlage von fluoreszenten Farbstoffen möglich. In einem umfassenden Ansatz wurden die in vitro-Experimente durch verschiedene in silico-Experimente ergänzt. Letztere basierten auf Random- Walk-Simulationen in Scheiben, die die in vitro-Situation mit ihren Unsicherheiten nachahmten. Die Lebensdauer einzelner Partikel wurde entweder so lang angesetzt, dass alle Partikel entkommen konnten, oder sie wurde so angepasst, dass sie den in den in vitro-Experimenten beobachteten Lebensdauerbeschränkungen entsprach. Ein Vergleich der mittleren ersten Durchgangszeit von unsterblichen Partikeln mit den korrigierten, lebensdauerbegrenzten Partikeln hat die Verwendung des Korrekturfaktors bestätigt. In ̈Ubereinstimmung mit der Narrow Escape Theorie wurde experimentell festgestellt, dass die mittlere erste Durchgangszeit unabhängig vom Startpunkt des Teilchens innerhalb der Domäne ist. Dies ist dann der Fall, wenn das Teilchen einen Mindestabstand zur Austrittsstelle einhält. Im Allgemeinen bilden die vorgestellten Random-Walk-Simulationen die in dieser Studie durchgeführten Experimente genau ab. Die erforderliche Hardware für die Einrichtung eines auf Astigmatismus basierenden 3D-Systems wurde in ein vorhandenes Mikroskop eingebaut. Erste Versuche, die gewonnenen 3D-Bilddaten zu analysieren, gaben einen Einblick in das Potenzial der Methode zur Untersuchung der Moleküldynamik im lebenden Trypanosom. Die volle Funktionalität wird mit der laufenden Verbesserung der Bildanalyse außerhalb dieser Arbeit realisiert werden. Ein Teil der Ergebnisse und Methoden dieser Dissertation wurde zur Veröffentlichung unter dem Titel ’Experiments in micro-patterned model membranes support the narrow escape theory’ eingereicht. KW - Freies Molekül KW - Kolloid KW - Bimolekulare Lipidschicht KW - Mikroskopie KW - Brownsche Bewegung KW - Narrow escape problem KW - mean first passage time KW - single-molecule localization microscopy KW - single particle tracking KW - Random-walk simulations Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319650 ER - TY - JOUR A1 - Maloukh, Lina A1 - Nazzal, Yousef A1 - Kumarappan, Alagappan A1 - Howari, Fares A1 - Ambika, Lakshmi Kesari A1 - Yahmadi, Rihab A1 - Sharma, Manish A1 - Iqbal, Jibran A1 - Al-Taani, Ahmed A. A1 - Salem, Imen Ben A1 - Xavier, Cijo M. A1 - Naseem, Muhamad T1 - Metagenomic analysis of the outdoor dust microbiomes: a case study from Abu Dhabi, UAE JF - Atmosphere N2 - Outdoor dust covers a shattered range of microbial agents from land over transportation, human microbial flora, which includes pathogen and commensals, and airborne from the environment. Dust aerosols are rich in bacterial communities that have a major impact on human health and living environments. In this study, outdoor samples from roadside barricades, safety walls, and fences (18 samples) were collected from Abu Dhabi, UAE and bacterial diversity was assessed through a 16S rRNA amplicon next generation sequencing approach. Clean data from HiSeq produced 1,099,892 total reads pairs for 18 samples. For all samples, taxonomic classifications were assigned to the OTUs (operational taxonomic units) representative sequence using the Ribosomal Database Project database. Analysis such as alpha diversity, beta diversity, differential species analysis, and species relative abundance were performed in the clustering of samples and a functional profile heat map was obtained from the OTUs by using bioinformatics tools. A total of 2814 OTUs were identified from those samples with a coverage of more than 99%. In the phylum, all 18 samples had most of the bacterial groups such as Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes. Twelve samples had Propionibacteria acnes and were mainly found in RD16 and RD3. Major bacteria species such as Propionibacteria acnes, Bacillus persicus, and Staphylococcus captis were found in all samples. Most of the samples had Streptococcus mitis, Staphylococcus capitis. and Nafulsella turpanensis and Enhydrobacter aerosaccus was part of the normal microbes of the skin. Salinimicrobium sp., Bacillus alkalisediminis, and Bacillus persicus are halophilic bacteria found in sediments. The heat map clustered the samples and species in vertical and horizontal classification, which represents the relationship between the samples and bacterial diversity. The heat map for the functional profile had high properties of amino acids, carbohydrate, and cofactor and vitamin metabolisms of all bacterial species from all samples. Taken together, our analyses are very relevant from the perspective of out-door air quality, airborne diseases, and epidemics, with broader implications for health safety and monitoring. KW - dust microbiomes KW - metagenomics KW - microbial diversity KW - pollution KW - GIS Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304391 SN - 2073-4433 VL - 14 IS - 2 ER - TY - JOUR A1 - Moustafa, Moataz A. M. A1 - Fouad, Eman A. A1 - Ibrahim, Emad A1 - Erdei, Anna Laura A1 - Kárpáti, Zsolt A1 - Fónagy, Adrien T1 - The comparative toxicity, biochemical and physiological impacts of chlorantraniliprole and indoxacarb on Mamestra brassicae (Lepidoptera: Noctuidae) JF - Toxics N2 - Background: The cabbage moth, Mamestra brassicae, is a polyphagous pest that attacks several crops. Here, the sublethal and lethal effects of chlorantraniliprole and indoxacarb were investigated on the developmental stages, detoxification enzymes, reproductive activity, calling behavior, peripheral physiology, and pheromone titer of M. brasssicae. Methods: To assess pesticide effects, the second instar larvae were maintained for 24 h on a semi-artificial diet containing insecticides at their LC\(_{10}\), LC\(_{30}\), and LC\(_{50}\) concentrations. Results: M. brassicae was more susceptible to chlorantraniliprole (LC\(_{50}\) = 0.35 mg/L) than indoxacarb (LC\(_{50}\) = 1.71 mg/L). A significantly increased developmental time was observed with both insecticides at all tested concentrations but decreases in pupation rate, pupal weight, and emergence were limited to the LC50 concentration. Reductions in both the total number of eggs laid per female and the egg viability were observed with both insecticides at their LC\(_{30}\) and LC\(_{50}\) concentrations. Both female calling activity and the sex pheromone (Z11-hexadecenyl acetate and hexadecenyl acetate) titer were significantly reduced by chlorantraniliprole in LC\(_{50}\) concentration. Antennal responses of female antennae to benzaldehyde and 3-octanone were significantly weaker than controls after exposure to the indoxocarb LC\(_{50}\) concentration. Significant reductions in the enzymatic activity of glutathione S-transferases, mixed-function oxidases, and carboxylesterases were observed in response to both insecticides. KW - toxicity KW - sublethal effects KW - chlorantraniliprole KW - indoxacarb KW - Mamestra brassicae Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-303931 SN - 2305-6304 VL - 11 IS - 3 ER -