@article{WeyrichBenzKarletal.2016, author = {Weyrich, Alexandra and Benz, Stephanie and Karl, Stephan and Jeschek, Marie and Jewgenow, Katarina and Fickel, J{\"o}rns}, title = {Paternal heat exposure causes DNA methylation and gene expression changes of Stat3 in Wild guinea pig sons}, series = {Ecology and evolution}, volume = {6}, journal = {Ecology and evolution}, publisher = {Wiley}, address = {Hoboken}, issn = {2045-7758}, doi = {10.1002/ece3.1993}, pages = {2657 -- 2666}, year = {2016}, abstract = {Epigenetic mechanisms convey environmental information through generations and can regulate gene expression. Epigenetic studies in wild mammals are rare, but enable understanding adaptation processes as they may occur in nature. In most wild mammal species, males are the dispersing sex and thus often have to cope with differing habitats and thermal changes more rapidly than the often philopatric females. As temperature is a major environmental selection factor, we investigated whether genetically heterogeneous Wild guinea pig (Cavia aperea) males adapt epigenetically to an increase in temperature, whether that response will be transmitted to the next generation(s), and whether it regulates mRNA expression. Five (F0) adult male guinea pigs were exposed to an increased ambient temperature for 2 months, corresponding to the duration of the species' spermatogenesis. To study the effect of heat, we focused on the main thermoregulatory organ, the liver. We analyzed CpG-methylation changes of male offspring (F1) sired before and after the fathers' heat treatment (as has recently been described in Weyrich et al. [Mol. Ecol., 2015]). Transcription analysis was performed for the three genes with the highest number of differentially methylated changes detected: the thermoregulation gene Signal Transducer and Activator of Transcription 3 (Stat3), the proteolytic peptidase gene Cathepsin Z (Ctsz), and Sirtuin 6 (Sirt6) with function in epigenetic regulation. Stat3 gene expression was significantly reduced (P < 0.05), which indicated a close link between CpG-methylation and expression levels for this gene. The two other genes did not show gene expression changes. Our results indicate the presence of a paternal transgenerational epigenetic effect. Quick adaptation to climatic changes may become increasingly relevant for the survival of wildlife species as global temperatures are rising.}, language = {en} } @article{WeyrichGuerreroAltamiranoYasaretal.2022, author = {Weyrich, Alexandra and Guerrero-Altamirano, Tania P. and Yasar, Selma and Czirjak, G{\´a}bor-{\´A}rp{\´a}d and Wachter, Bettina and Fickel, J{\"o}rns}, title = {First Steps towards the development of epigenetic biomarkers in female cheetahs (Acinonyx jubatus)}, series = {Life : open access journal}, volume = {12}, journal = {Life : open access journal}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2075-1729}, doi = {10.3390/life12060920}, pages = {16}, year = {2022}, abstract = {Free-ranging cheetahs (Acinonyx jubatus) are generally healthy, whereas cheetahs under human care, such as those in zoological gardens, suffer from ill-defined infectious and degenerative pathologies. These differences are only partially explained by husbandry management programs because both groups share low genetic diversity. However, mounting evidence suggests that physiological differences between populations in different environments can be tracked down to differences in epigenetic signatures. Here, we identified differentially methylated regions (DMRs) between free-ranging cheetahs and conspecifics in zoological gardens and prospect putative links to pathways relevant to immunity, energy balance and homeostasis. Comparing epigenomic DNA methylation profiles obtained from peripheral blood mononuclear cells (PBMCs) from eight free-ranging female cheetahs from Namibia and seven female cheetahs living in zoological gardens within Europe, we identified DMRs of which 22 were hypermethylated and 23 hypomethylated. Hypermethylated regions in cheetahs under human care were located in the promoter region of a gene involved in host-pathogen interactions (KLC1) and in an intron of a transcription factor relevant for the development of pancreatic beta-cells, liver, and kidney (GLIS3). The most canonical mechanism of DNA methylation in promoter regions is assumed to repress gene transcription. Taken together, this could indicate that hypermethylation at the promoter region of KLC1 is involved in the reduced immunity in cheetahs under human care. This approach can be generalized to characterize DNA methylation profiles in larger cheetah populations under human care with a more granular longitudinal data collection, which, in the future, could be used to monitor the early onset of pathologies, and ultimately translate into the development of biomarkers with prophylactic and/or therapeutic potential.}, language = {en} } @article{WeyrichJeschekSchrapersetal.2018, author = {Weyrich, Alexandra and Jeschek, Marie and Schrapers, Katharina T. and Lenz, Dorina and Chung, Tzu Hung and Ruebensam, Kathrin and Yasar, Sermin and Schneemann, Markus and Ortmann, Sylvia and Jewgenow, Katarina and Fickel, J{\"o}rns}, title = {Diet changes alter paternally inherited epigenetic pattern in male Wild guinea pigs}, series = {Environmental Epigenetics}, volume = {4}, journal = {Environmental Epigenetics}, number = {2}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {2058-5888}, doi = {10.1093/eep/dvy011}, pages = {12}, year = {2018}, abstract = {Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impact on the offspring's adaptability to changes in diet composition, we investigated if low protein diet (LPD) in F0 males caused epigenetic alterations in their subsequently sired sons. We therefore fed F0 male Wild guinea pigs with a diet lowered in protein content (LPD) and investigated DNA methylation in sons sired before and after their father's LPD treatment in both, liver and testis tissues. Our results point to a 'heritable epigenetic response' of the sons to the fathers' dietary change. Because we detected methylation changes also in the testis tissue, they are likely to be transmitted to the F2 generation. Gene-network analyses of differentially methylated genes in liver identified main metabolic pathways indicating a metabolic reprogramming ('metabolic shift'). Epigenetic mechanisms, allowing an immediate and inherited adaptation may thus be important for the survival of species in the context of a persistently changing environment, such as climate change.}, language = {en} } @article{WeyrichLenzFickel2018, author = {Weyrich, Alexandra and Lenz, Dorina and Fickel, J{\"o}rns}, title = {Environmental Change-Dependent Inherited Epigenetic Response}, series = {GENES}, volume = {10}, journal = {GENES}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2073-4425}, doi = {10.3390/genes10010004}, pages = {15}, year = {2018}, abstract = {Epigenetic modifications are a mechanism conveying environmental information to subsequent generations via parental germ lines. Research on epigenetic responses to environmental changes in wild mammals has been widely neglected, as well as studies that compare responses to changes in different environmental factors. Here, we focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to either diet (~40\% less protein) or temperature increase (10 °C increased temperature). Because both experiments focused on the liver as the main metabolic and thermoregulation organ, we were able to decipher if epigenetic changes differed in response to different environmental changes. Reduced representation bisulfite sequencing (RRBS) revealed differentially methylated regions (DMRs) in annotated genomic regions in sons sired before (control) and after the fathers' treatments. We detected both a highly specific epigenetic response dependent on the environmental factor that had changed that was reflected in genes involved in specific metabolic pathways, and a more general response to changes in outer stimuli reflected by epigenetic modifications in a small subset of genes shared between both responses. Our results indicated that fathers prepared their offspring for specific environmental changes by paternally inherited epigenetic modifications, suggesting a strong paternal contribution to adaptive processes.}, language = {en} } @article{WeyrichLenzJescheketal.2016, author = {Weyrich, Alexandra and Lenz, Dorina and Jeschek, Marie and Tzu Hung Chung, and Ruebensam, Kathrin and Goeritz, Frank and Jewgenow, Katarina and Fickel, J{\"o}rns}, title = {Paternal intergenerational epigenetic response to heat exposure in male Wild guinea pigs}, series = {Molecular ecology}, volume = {25}, journal = {Molecular ecology}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0962-1083}, doi = {10.1111/mec.13494}, pages = {1729 -- 1740}, year = {2016}, abstract = {Epigenetic modifications, of which DNA methylation is the best studied one, can convey environmental information through generations via parental germ lines. Past studies have focused on the maternal transmission of epigenetic information to the offspring of isogenic mice and rats in response to external changes, whereas heterogeneous wild mammals as well as paternal epigenetic effects have been widely neglected. In most wild mammal species, males are the dispersing sex and have to cope with differing habitats and thermal changes. As temperature is a major environmental factor we investigated if genetically heterogeneous Wild guinea pig (Cavia aperea) males can adapt epigenetically to an increase in temperature and if that response will be transmitted to the next generation(s). Five adult male guinea pigs (F0) were exposed to an increased ambient temperature for 2 months, i.e. the duration of spermatogenesis. We studied the liver (as the main thermoregulatory organ) of F0 fathers and F1 sons, and testes of F1 sons for paternal transmission of epigenetic modifications across generation(s). Reduced representation bisulphite sequencing revealed shared differentially methylated regions in annotated areas between F0 livers before and after heat treatment, and their sons' livers and testes, which indicated a general response with ecological relevance. Thus, paternal exposure to a temporally limited increased ambient temperature led to an 'immediate' and 'heritable' epigenetic response that may even be transmitted to the F2 generation. In the context of globally rising temperatures epigenetic mechanisms may become increasingly relevant for the survival of species.}, language = {en} } @article{WeyrichYasarLenzetal.2020, author = {Weyrich, Alexandra and Yasar, Selma and Lenz, Dorina and Fickel, J{\"o}rns}, title = {Tissue-specific epigenetic inheritance after paternal heat exposure in male wild guinea pigs}, series = {Mammalian genome}, volume = {31}, journal = {Mammalian genome}, number = {5-6}, publisher = {Springer}, address = {New York}, issn = {0938-8990}, doi = {10.1007/s00335-020-09832-6}, pages = {157 -- 169}, year = {2020}, abstract = {External temperature change has been shown to modify epigenetic patterns, such as DNA methylation, which regulates gene expression. DNA methylation is heritable, and as such provides a mechanism to convey environmental information to subsequent generations. Studies on epigenetic response to temperature increase are still scarce in wild mammals, even more so studies that compare tissue-specific epigenetic responses. Here, we aim to address differential epigenetic responses on a gene and gene pathway level in two organs, liver and testis. We chose these organs, because the liver is the main metabolic and thermoregulation organ, and epigenetic modifications in testis are potentially transmitted to the F2 generation. We focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to an ambient temperature increase of 10 degrees C, and investigated differential methylated regions of sons sired before and after the paternal exposure using Reduced Representation Bisulfite Sequencing. We detected both a highly tissue-specific epigenetic response, reflected in genes involved in organ-specific metabolic pathways, and a more general regulation of single genes epigenetically modified in both organs. We conclude that genomes are context-specifically differentially epigenetically regulated in response to temperature increase. These findings emphasize the epigenetic relevance in cell differentiation, which is essential for the specific function(s) of complex organs, and is represented in a diverse molecular regulation of genes and gene pathways. The results also emphasize the paternal contribution to adaptive processes.}, language = {en} } @article{WhitcombNguyenBrueckneretal.2018, author = {Whitcomb, Sarah J. and Nguyen, Huu Cuong and Br{\"u}ckner, Franziska and Hesse, Holger and Hoefgen, Rainer}, title = {CYSTATHIONINE GAMMA-SYNTHASE activity in rice is developmentally regulated and strongly correlated with sulfate}, series = {Plant science : an international journal of experimental plant biology}, volume = {270}, journal = {Plant science : an international journal of experimental plant biology}, publisher = {Elsevier}, address = {Clare}, issn = {0168-9452}, doi = {10.1016/j.plantsci.2018.02.016}, pages = {234 -- 244}, year = {2018}, abstract = {An important goal of rice cultivar development is improvement of protein quality, especially with respect to essential amino acids such as methionine. With the goal of increasing seed methionine content, we generated Oryza sativa ssp. japonica cv. Taipei 309 transgenic lines expressing a feedback-desensitized CYSTATHIONINE GAMMA-SYNTHASE from Arabidopsis thaliana (AtD-CGS) under the control of the maize ubiquitin promoter. Despite persistently elevated cystathionine gamma-synthase (CGS) activity in the AtD-CGS transgenic lines relative to untransformed Taipei, sulfate was the only sulfur-containing compound found to be elevated throughout vegetative development. Accumulation of methionine and other sulfur-containing metabolites was limited to the leaves of young plants. Sulfate concentration was found to strongly and positively correlate with CGS activity across vegetative development, irrespective of whether the activity was provided by the endogenous rice CGS or by a combination of endogenous and AtD-CGS. Conversely, the concentrations of glutathione, valine, and leucine were clearly negatively correlated with CGS activity in the same tissues. We also observed a strong decrease in CGS activity in both untransformed Taipei and the AtD-CGS transgenic lines as the plants approached heading stage. The mechanism for this downregulation is currently unknown and of potential importance for efforts to increase methionine content in rice.}, language = {en} } @article{WhiteleyHaugKleinetal.2017, author = {Whiteley, Liam and Haug, Maria and Klein, Kristina and Willmann, Matthias and Bohn, Erwin and Chiantia, Salvatore and Schwarz, Sandra}, title = {Cholesterol and host cell surface proteins contribute to cell-cell fusion induced by the Burkholderia type VI secretion system 5}, series = {PLoS one}, volume = {12}, journal = {PLoS one}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0185715}, pages = {16}, year = {2017}, abstract = {Following escape into the cytoplasm of host cells, Burkholderia pseudomallei and the related species Burkholderia thailandensis employ the type VI secretion system 5 ( T6SS-5) to induce plasma membrane fusion with an adjacent host cell. This process leads to the formation of multinucleated giant cells and facilitates bacterial access to an uninfected host cell in a direct manner. Despite its importance in virulence, the mechanism of the T6SS-5 and the role of host cell factors in cell-cell fusion remain elusive. To date, the T6SS-5 is the only system of bacterial origin known to induce host-cell fusion. To gain insight into the nature of T6SS-5-stimulated membrane fusion, we investigated the contribution of cholesterol and proteins exposed on the host cell surface, which were shown to be critically involved in virus-mediated giant cell formation. In particular, we analyzed the effect of host cell surface protein and cholesterol depletion on the formation of multinucleated giant cells induced by B. thailandensis. Acute protease treatment of RAW264.7 macrophages during infection with B. thailandensis followed by agarose overlay assays revealed a strong reduction in the number of cell-cell fusions compared with EDTA treated cells. Similarly, proteolytic treatment of specifically infected donor cells or uninfected recipient cells significantly decreased multinucleated giant cell formation. Furthermore, modulating host cell cholesterol content by acute cholesterol depletion from cellular membranes by methyl-beta-cyclodextrin treatment or exogenous addition of cholesterol impaired the ability of B. thailandensis to induce cell-cell fusions. The requirement of physiological cholesterol levels suggests that the membrane organization or mechanical properties of the lipid bilayer influence the fusion process. Altogether, our data suggest that membrane fusion induced by B. pseudomallei and B. thailandensis involves a complex interplay between the T6SS-5 and the host cell.}, language = {en} } @article{WicaksonoBraunBernhardtetal.2022, author = {Wicaksono, Wisnu Adi and Braun, Maria and Bernhardt, J{\"o}rg and Riedel, Katharina and Cernava, Tomislav and Berg, Gabriele}, title = {Trade-off for survival}, series = {Environment international : a journal of science, technology, health, monitoring and policy}, volume = {168}, journal = {Environment international : a journal of science, technology, health, monitoring and policy}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {1873-6750}, doi = {10.1016/j.envint.2022.107474}, pages = {13}, year = {2022}, abstract = {The environmental micmbiota is increasingly exposed to chemical pollution. While the emergence of multi-resistant pathogens is recognized as a global challenge, our understanding of antimicrobial resistance (AMR) development from native microbiomes and the risks associated with chemical exposure is limited. By implementing a lichen as a bioindicator organism and model for a native microbiome, we systematically examined responses towards antimicrobials (colistin, tetracycline, glyphosate, and alkylpyrazine). Despite an unexpectedly high resilience, we identified potential evolutionary consequences of chemical exposure in terms of composition and functioning of native bacterial communities. Major shifts in bacterial composition were observed due to replacement of naturally abundant taxa; e.g. Chthoniobacterales by Pseudomonadales. A general response, which comprised activation of intrinsic resistance and parallel reduction of metabolic activity at RNA and protein levels was deciphered by a multi-omics approach. Targeted analyses of key taxa based on metagenome-assembled genomes reflected these responses but also revealed diversified strategies of their players. Chemical-specific responses were also observed, e.g., glyphosate enriched bacterial r-strategists and activated distinct ARGs. Our work demonstrates that the high resilience of the native micmbiota toward antimicrobial exposure is not only explained by the presence of antibiotic resistance genes but also adapted metabolic activity as a trade-off for survival. Moreover, our results highlight the importance of native microbiomes as important but so far neglected AMR reservoirs. We expect that this phenomenon is representative for a wide range of environmental microbiota exposed to chemicals that potentially contribute to the emergence of antibiotic-resistant bacteria from natural environments.}, language = {en} } @article{Wichmann2002, author = {Wichmann, Matthias}, title = {Survival in changing environments : modeling the impact of climate change and land use on raptors in arid savanna}, pages = {103 S.}, year = {2002}, language = {en} } @article{WichmannDeanJeltsch2006, author = {Wichmann, Matthias and Dean, W. R. J. and Jeltsch, Florian}, title = {Predicting the breeding success of large raptors in arid southern Africa : a first assessment}, year = {2006}, abstract = {Raptors are often priorities for conservation efforts and breeding success is a target measure for assessing their conservation status. The breeding success of large raptors in and southern Africa is thought to be higher in years of high rainfall. While this correlation has been found in several studies, it has not yet been shown for data from a wider geographical area. In conservation research, it is important to explore the differences between spatially- separated populations to estimate and to compare their conservation status, and to deduce specific management strategies. Using a theoretical approach, we develop a simplistic model to explain the breeding success-rainfall relationship in large African raptors at larger spatial scales. Secondly, we validate this model and we show that the inclusion of field data leads to consistent predictions. In particular, we recommend that the average size of the 'effective territory' should be included in the relationship between annual rainfall and breeding success of raptors in and southern Africa. Accordingly, we suggest that breeding success is a function of precipitation and inter- nest distance. We present a new measure of territory quality depending on rainfall and territory size. We suggest that our model provides a useful first approach to assess breeding success in large raptors of and southern Africa. However, we strongly emphasise the need to gather more data to further verify our model. A general problem in conservation research is to compare the status of populations assessed in different study areas under changing environmental conditions. Our simplistic approach indicates that this problem can be overcome by using a weighted evaluation of a target measure (i.e. breeding success), taking regional differences into account}, language = {en} } @article{WichmannGroeneveldJeltschetal.2005, author = {Wichmann, Matthias and Groeneveld, J{\"u}rgen and Jeltsch, Florian and Grimm, Volker}, title = {Mitigation of climate change impacts on raptors by behavioural adaptation : ecological buffering mechanisms}, issn = {0921-8181}, year = {2005}, abstract = {The predicted climate change causes deep concerns on the effects of increasing temperatures and changing precipitation patterns on species viability and, in turn, on biodiversity. Models of Population Viability Analysis (PVA) provide a powerful tool to assess the risk of species extinction. However, most PVA models do not take into account the potential effects of behavioural adaptations. Organisms might adapt to new environmental situations and thereby mitigate negative effects of climate change. To demonstrate such mitigation effects, we use an existing PVA model describing a population of the tawny eagle (Aquila rapax) in the southern Kalahari. This model does not include behavioural adaptations. We develop a new model by assuming that the birds enlarge their average territory size to compensate for lower amounts of precipitation. Here, we found the predicted increase in risk of extinction due to climate change to be much lower than in the original model. However, this "buffering" of climate change by behavioural adaptation is not very effective in coping with increasing interannual variances. We refer to further examples of ecological "buffering mechanisms" from the literature and argue that possible buffering mechanisms should be given due consideration when the effects of climate change on biodiversity are to be predicted. (c) 2004 Elsevier B.V. All rights reserved}, language = {en} } @article{WichmannGroeneveldJeltschetal.2005, author = {Wichmann, Matthias and Groeneveld, J{\"u}rgen and Jeltsch, Florian and Grimm, Volker}, title = {Mitigation of climate change impacts on raptors by behavioural adaption : ecological buffering mechanism}, year = {2005}, language = {en} } @article{WichmannJeltschDeanetal.2002, author = {Wichmann, Matthias and Jeltsch, Florian and Dean, Richard and Moloney, Kirk A. and Wissel, Christian}, title = {Does climate change in arid savanna affect the population persistence of raptors?}, year = {2002}, language = {en} } @article{WichmannJeltschDeanetal.2002, author = {Wichmann, Matthias and Jeltsch, Florian and Dean, Richard and Moloney, Kirk A. and Wissel, Christian}, title = {Weather does matter : simulating population dynamics of tawny eagle (Aquila rapax) under various rainfall scenarios}, year = {2002}, language = {en} } @article{WieczorekKruseEppetal.2017, author = {Wieczorek, Mareike and Kruse, Stefan and Epp, Laura Saskia and Kolmogorov, Alexei and Nikolaev, Anatoly N. and Heinrich, Ingo and Jeltsch, Florian and Pestryakova, Luidmila Agafyevna and Zibulski, Romy and Herzschuh, Ulrike}, title = {Dissimilar responses of larch stands in northern Siberia to increasing temperatures-a field and simulation based study}, series = {Ecology : a publication of the Ecological Society of America}, volume = {98}, journal = {Ecology : a publication of the Ecological Society of America}, publisher = {Wiley}, address = {Hoboken}, issn = {0012-9658}, doi = {10.1002/ecy.1887}, pages = {2343 -- 2355}, year = {2017}, abstract = {Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. In our study, which was conducted in the Taimyr Depression in the North Siberian Lowlands, w present a combined field-and model-based approach helping us to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that tree density is highest in the forest-tundra, and average tree size decreases from closed forest to single-tree tundra. Age-structure analyses indicate that the trees in the closed forest and forest-tundra have been present for at least similar to 240 yr. At all sites except the most southerly ones, past establishment is positively correlated with regional temperature increase. In the single-tree tundra, however, a change in growth form from krummholz to erect trees, beginning similar to 130 yr ago, rather than establishment date has been recorded. Seed mass decreases from south to north, while seed quantity increases. Simulations with LAVESI (Larix Vegetation Simulator) further suggest that relative density changes strongly in response to a warming signal in the forest-tundra while intra-specific competition limits densification in the closed forest and seed limitation hinders densification in the single-tree tundra. We find striking differences in strength and timing of responses to recent climate warming. While forest-tundra stands recently densified, recruitment is almost non-existent at the southern and northern end of the ecotone due to autecological processes. Palaeo-treelines may therefore be inappropriate to infer past temperature changes at a fine scale. Moreover, a lagged treeline response to past warming will, via feedback mechanisms, influence climate change in the future.}, language = {en} } @article{WiegandJeltschWard2004, author = {Wiegand, K. and Jeltsch, Florian and Ward, D.}, title = {Minimum recruitment frequency in plants with episodic recruitment}, year = {2004}, abstract = {There is concern about the lack of recruitment of Acacia trees in the Negev desert of Israel. We have developed three models to estimate the frequency of recruitment necessary for long-term population survival (i.e. positive average population growth for 1,000 years and <10\% probability of extinction). Two models assume purely episodic recruitment based on the general notion that recruitment in and environments is highly episodic. They differ in that the deterministic model investigates average dynamics while the stochastic model does not. Studies indicating that recruitment episodes in and environments have been overemphasized motivated the development of the third model. This semi-stochastic model simulates a mixture of continuous and episodic recruitment. Model analysis was done analytically for the deterministic model and via running model simulations for the stochastic and semi-stochastic models. The deterministic and stochastic models predict that, on average, 2.2 and 3.7 recruitment events per century, respectively, are necessary to sustain the population. According to the semi-stochastic model, 1.6 large recruitment events per century and an annual probability of 50\% that a small recruitment event occurs are needed. A consequence of purely episodic recruitment is that all recruitment episodes produce extremely large numbers of recruits (i.e. at odds with field observations), an evaluation that holds even when considering that rare events must be large. Thus, the semi- stochastic model appears to be the most realistic model. Comparing the prediction of the semi-stochastic model to field observations in the Negev desert shows that the absence of observations of extremely large recruitment events is no reason for concern. However, the almost complete absence of small recruitment events is a serious reason for concern. The lack of recruitment may be due to decreased densities of large mammalian herbivores and might be further exacerbated by possible changes in climate, both in terms of average precipitation and the temporal distribution of rain}, language = {en} } @article{WiegandJeltschWard2000, author = {Wiegand, K. and Jeltsch, Florian and Ward, D.}, title = {Do spatial effects play a role in the spatial distribution of desert dwelling Acacias?}, year = {2000}, language = {en} } @article{WiegandSchmidtJeltschetal.2000, author = {Wiegand, K. and Schmidt, H. and Jeltsch, Florian and Ward, D.}, title = {Linking a spatially-explicit model of acacias to GIS and remotely-sensed data}, year = {2000}, language = {en} } @article{WiegandWardThulkeetal.2000, author = {Wiegand, K. and Ward, D. and Thulke, Hans-Hermann and Jeltsch, Florian}, title = {From snap-shot information to long-term population dynamics of Acacias by a simulation model}, year = {2000}, language = {en} } @article{WiegandJeltsch2000, author = {Wiegand, T. and Jeltsch, Florian}, title = {Long-term dynamics in arid and semi-arid ecosystems : synthesis of a workshop}, year = {2000}, language = {en} } @article{WiegmannRutschmannWillemsen2017, author = {Wiegmann, Alex and Rutschmann, Ronja and Willemsen, Pascale}, title = {Empirically investigating the concept of lying}, series = {Journal of Indian Council of Philosophical Research}, volume = {34}, journal = {Journal of Indian Council of Philosophical Research}, publisher = {Springer}, address = {New Dehli}, issn = {0970-7794}, doi = {10.1007/s40961-017-0112-z}, pages = {591 -- 609}, year = {2017}, abstract = {Lying is an everyday moral phenomenon about which philosophers have written a lot. Not only the moral status of lying has been intensively discussed but also what it means to lie in the first place. Perhaps the most important criterion for an adequate definition of lying is that it fits with people's understanding and use of this concept. In this light, it comes as a surprise that researchers only recently started to empirically investigate the folk concept of lying. In this paper, we describe three experimental studies which address the following questions: Does a statement need to be objectively false in order to constitute lying? Does lying necessarily include the intention to deceive? Can one lie by omitting relevant facts?}, language = {en} } @article{WiemannAndersenBerggrenetal.2010, author = {Wiemann, Annika and Andersen, Liselotte W. and Berggren, Per and Siebert, Ursula and Benke, Harald and Teilmann, Jonay and Lockyer, Christina and Pawliczka, Iwona and Skora, Krysztof and Roos, Aanna and Lyrholm, Thomas and Paulus, Kirsten B. and Ketmaier, Valerio}, title = {Mitochondrial Control Region and microsatellite analyses on harbour porpoise (Phocoena phocoena) unravel population differentiation in the Baltic Sea and adjacent waters}, issn = {1566-0621}, doi = {10.1007/s10592-009-0023-x}, year = {2010}, abstract = {The population status of the harbour porpoise (Phocoena phocoena) in the Baltic area has been a continuous matter of debate. Here we present the by far most comprehensive genetic population structure assessment to date for this region, both with regard to geographic coverage and sample size: 497 porpoise samples from North Sea, Skagerrak, Kattegat, Belt Sea, and Inner Baltic Sea were sequenced at the mitochondrial Control Region and 305 of these specimens were typed at 15 polymorphic microsatellite loci. Samples were stratified according to sample type (stranding vs. by- caught), sex, and season (breeding vs. non-breeding season). Our data provide ample evidence for a population split between the Skagerrak and the Belt Sea, with a transition zone in the Kattegat area. Among other measures, this was particularly visible in significant frequency shifts of the most abundant mitochondrial haplotypes. A particular haplotype almost absent in the North Sea was the most abundant in Belt Sea and Inner Baltic Sea. Microsatellites yielded a similar pattern (i.e., turnover in occurrence of clusters identified by STRUCTURE). Moreover, a highly significant association between microsatellite assignment and unlinked mitochondrial haplotypes further indicates a split between North Sea and Baltic porpoises. For the Inner Baltic Sea, we consistently recovered a small, but significant separation from the Belt Sea population. Despite recent arguments that separation should exceed a predefined threshold before populations shall be managed separately, we argue in favour of precautionary acknowledging the Inner Baltic porpoises as a separate management unit, which should receive particular attention, as it is threatened by various factors, in particular local fishery measures.}, language = {en} } @article{WienholdMacriNouaillesetal.2018, author = {Wienhold, Sandra-Maria and Macri, Mario and Nouailles, Geraldine and Dietert, Kristina and Gurtner, Corinne and Gruber, Achim D. and Heimesaat, Markus M. and Lienau, Jasmin and Schumacher, Fabian and Kleuser, Burkhard and Opitz, Bastian and Suttorp, Norbert and Witzenrath, Martin and M{\"u}ller-Redetzky, Holger C.}, title = {Ventilator-induced lung injury is aggravated by antibiotic mediated microbiota depletion in mice}, series = {Critical Care}, volume = {22}, journal = {Critical Care}, number = {282}, publisher = {BMC}, address = {London}, issn = {1466-609X}, doi = {10.1186/s13054-018-2213-8}, pages = {12}, year = {2018}, abstract = {BackgroundAntibiotic exposure alters the microbiota, which can impact the inflammatory immune responses. Critically ill patients frequently receive antibiotic treatment and are often subjected to mechanical ventilation, which may induce local and systemic inflammatory responses and development of ventilator-induced lung injury (VILI). The aim of this study was to investigate whether disruption of the microbiota by antibiotic therapy prior to mechanical ventilation affects pulmonary inflammatory responses and thereby the development of VILI.MethodsMice underwent 6-8weeks of enteral antibiotic combination treatment until absence of cultivable bacteria in fecal samples was confirmed. Control mice were housed equally throughout this period. VILI was induced 3 days after completing the antibiotic treatment protocol, by high tidal volume (HTV) ventilation (34ml/kg; positive end-expiratory pressure=2 cmH(2)O) for 4h. Differences in lung function, oxygenation index, pulmonary vascular leakage, macroscopic assessment of lung injury, and leukocyte and lymphocyte differentiation were assessed. Control groups of mice ventilated with low tidal volume and non-ventilated mice were analyzed accordingly.ResultsAntibiotic-induced microbiota depletion prior to HTV ventilation led to aggravation of VILI, as shown by increased pulmonary permeability, increased oxygenation index, decreased pulmonary compliance, enhanced macroscopic lung injury, and increased cytokine/chemokine levels in lung homogenates.ConclusionsDepletion of the microbiota by broad-spectrum antibiotics prior to HTV ventilation renders mice more susceptible to developing VILI, which could be clinically relevant for critically ill patients frequently receiving broad-spectrum antibiotics.}, language = {en} } @article{WiesnerLoxdaleKoehleretal.2011, author = {Wiesner, Kerstin R. and Loxdale, Hugh D. and K{\"o}hler, G{\"u}nter and Schneider, Anja R. R. and Tiedemann, Ralph and Weisser, Wolfgang W.}, title = {Patterns of local and regional genetic structuring in the meadow grasshopper, Chorthippus parallelus (Orthoptera: Acrididae), in Central Germany revealed using microsatellite markers}, series = {Biological journal of the Linnean Society : a journal of evolution}, volume = {103}, journal = {Biological journal of the Linnean Society : a journal of evolution}, number = {4}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0024-4066}, doi = {10.1111/j.1095-8312.2011.01698.x}, pages = {875 -- 890}, year = {2011}, abstract = {The meadow grasshopper, Chorthippus parallelus (Zetterstedt), is common and widespread in Central Europe, with a low dispersal range per generation. A population study in Central Germany (Frankenwald and Thuringer Schiefergebirge) showed strong interpopulation differences in abundance and individual fitness. We examined genetic variability using microsatellite markers within and between 22 populations in a short-to long-distance sampling (19 populations, Frankenwald, Schiefergebirge, as well as a southern transect), and in the Erzgebirge region (three populations), with the latter aiming to check for effects as a result of historical forest cover. Of the 671 C. parallelus captured, none was macropterous (functionally winged). All populations showed a high level of expected and observed heterozygosity (mean 0.80-0.90 and 0.60-0.75, respectively), whereas there was evidence of inbreeding (F(IS) values all positive). Allelic richness for all locus-population combinations was high (mean 9.3-11.2), whereas alleles per locus ranged from 15-62. At a local level, genic and genotypic differences were significant. Pairwise F(ST) values were in the range 0.00-0.04, indicating little interpopulation genetic differentiation. Similarly, the calculated gene flow was very high, based on the respective F(ST) (19.5) and using private alleles (7.7). A Neighbour-joining tree using Nei's D(A) and principal coordinate analysis separated two populations that were collected in the Erzgebirge region. Populations from this region may have escaped the effects of the historical forest cover. The visualization of the spatial arrangement of genotypes revealed one geographical barrier to gene flow in the short-distance sampling.}, language = {en} } @article{WiesnerSalmikangasAuerbachetal.2000, author = {Wiesner, Sebastian and Salmikangas, Paula and Auerbach, Daniel and Himmel, Mirko and Kempa, Stefan and Hayes, Kathrin and Pacholsky, Dirk and Taivainen, Anu and Schr{\"o}der, Rolf and Carpen, Olli and F{\"u}rst, Dieter Oswald}, title = {Indications for a novel muscular dystrophy pathway : gamma-filamin, the muscle-specific filamin isoform, intgeracts with myotilin}, year = {2000}, language = {en} } @article{WiethausMuellerNeumannetal.2009, author = {Wiethaus, Jessica and Mueller, Alexandra and Neumann, Meina and Neumann, Sandra and Leimk{\"u}hler, Silke and Narberhaus, Franz and Masepohl, Bernd}, title = {Specific interactions between four Molybdenum-binding proteins contribute to Mo-dependent gene regulation in Rhodobacter capsulatus}, issn = {0021-9193}, doi = {10.1128/Jb.00526-09}, year = {2009}, abstract = {The phototrophic purple bacterium Rhodobacter capsulatus encodes two transcriptional regulators, MopA and MopB, with partially overlapping and specific functions in molybdate-dependent gene regulation. Both MopA and MopB consist of an N-terminal DNA-binding helix-turn-helix domain and a C-terminal molybdate-binding di-MOP domain. They formed homodimers as apo-proteins and in the molybdate-bound state as shown by yeast two-hybrid (Y2H) studies, glutaraldehyde cross-linking, gel filtration chromatography, and copurification experiments. Y2H studies suggested that both the DNA- binding and the molybdate-binding domains contribute to dimer formation. Analysis of molybdate binding to MopA and MopB revealed a binding stoichiometry of four molybdate oxyanions per homodimer. Specific interaction partners of MopA and MopB were the molybdate transporter ATPase ModC and the molbindin-like Mop protein, respectively. Like other molbindins, the R. capsulatus Mop protein formed hexamers, which were stabilized by binding of six molybdate oxyanions per hexamer. Heteromer formation of MopA and MopB was shown by Y2H studies and copurification experiments. Reporter gene activity of a strictly MopA-dependent mop-lacZ fusion in mutant strains defective for either mopA, mopB, or both suggested that MopB negatively modulates expression of the mop promoter. We propose that depletion of the active MopA homodimer pool by formation of MopA-MopB heteromers might represent a fine-tuning mechanism controlling mop gene expression.}, language = {en} } @article{WildishPavesiKetmaier2012, author = {Wildish, J. and Pavesi, Laura and Ketmaier, Valerio}, title = {Talitrid amphipods (Crustacea: Amphipoda: Talitridae) and the driftwood ecological niche a morphological and molecular study}, series = {Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor \& Francis   1.1967 -}, volume = {46}, journal = {Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor \& Francis   1.1967 -}, number = {43-44}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {0022-2933}, doi = {10.1080/00222933.2012.717971}, pages = {2677 -- 2700}, year = {2012}, abstract = {Coastal regions of the North East Atlantic and Mediterranean Seas have four known species of driftwood talitrids. Records are extremely scanty, often limited to the type locality and dating to 1950. We were able to study three of them, all belonging to the genus Macarorchestia, using fresh and archived samples including type material. Allometric and molecular analyses support: (1) a close relationship among all the three classically defined Macarorchestia species, (2) Macarorchestia was well separated from non-driftwood taxa, and (3) a putative new driftwood talitrid discovered during this study was not closely related to Macarorchestia. Genetic divergence between the new species and Macarorchestia remyi is as high as the average distance among a number of talitrid species included in the study for comparison. A key is provided to identify all three of the presently known species of Macarorchestia, using morphological characters employed in the allometric study.}, language = {en} } @article{WilkeBoekerMummetal.2022, author = {Wilke, Liza and Boeker, Sonja and Mumm, Rebecca and Groth, Detlef}, title = {The Social status influences human growth}, series = {Human biology and public health}, volume = {2021}, journal = {Human biology and public health}, number = {3, Summer School Supplement}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {2748-9957}, doi = {10.52905/hbph2021.3.22}, pages = {9}, year = {2022}, abstract = {Background: In the animal kingdom body size is often linked to dominance and subsequently the standing in social hierarchy. Similarly, human growth has been associated and linked to socioeconomic factors, including one's social status. This has already been proposed in the early 1900s where data on young German school girls from different social strata have been compared. Objectives: This paper aims to summarize and analyze these results and make them accessible for non-German speakers. The full English translation of the historic work of Dikanski (Dikanski, 1914) is available as a supplement. Further, this work aims to compare the historical data with modern references, to test three hypotheses: (1) higher social class is positively associated with body height and weight, (2) affluent people from the used historical data match modern references in weight and height and (3) weight distributions are skewed in both modern and historical populations. Methods: Comparison of historical data from 1914 with WHO and 1980s German data. The data sets, for both body weight and height for 6.0- and 7.0-year-old girls, were fitted onto centile curves and quantile correlation coefficients were calculated. Results: In historical data social status is positively associated with body height and weight while both are also normally distributed, which marks a significant difference to modern references. Conclusion: Social status is positively associated with height, signaling social dominance, making children of affluent classes taller. Children from the historical data do not reach the average height of modern children, even under the best environmental conditions. The children of the upper social class were not skewed in weight distribution, although they had the means to become as obese as modern children.}, language = {en} } @article{WilliFischer2005, author = {Willi, Yvonne and Fischer, Markus}, title = {Genetic rescue effect in interconnected populations of small and large size of the self-incompatible Ranunculus reptans}, year = {2005}, language = {en} } @article{WillivanBuskirkFischer2005, author = {Willi, Yvonne and van Buskirk, J. and Fischer, Markus}, title = {A threefold genetic allee effect : Population size affects cross-compatibility, inbreeding depression and drift load in the self-incompatible Ranunculus reptans}, issn = {0016-6731}, year = {2005}, language = {en} } @article{WiltingPatelPfestorfetal.2016, author = {Wilting, A. and Patel, R. and Pfestorf, Hans and Kern, C. and Sultan, K. and Ario, A. and Penaloza, F. and Kramer-Schadt, S. and Radchuk, Viktoriia and Foerster, D. W. and Fickel, J{\"o}rns}, title = {Evolutionary history and conservation significance of the Javan leopard Panthera pardus melas}, series = {Journal of zoology : proceedings of the Zoological Society of London}, volume = {299}, journal = {Journal of zoology : proceedings of the Zoological Society of London}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0952-8369}, doi = {10.1111/jzo.12348}, pages = {239 -- 250}, year = {2016}, abstract = {The leopard Panthera pardus is widely distributed across Africa and Asia; however, there is a gap in its natural distribution in Southeast Asia, where it occurs on the mainland and on Java but not on the interjacent island of Sumatra. Several scenarios have been proposed to explain this distribution gap. Here, we complemented an existing dataset of 68 leopard mtDNA sequences from Africa and Asia with mtDNA sequences (NADH5+ ctrl, 724bp) from 19 Javan leopards, and hindcasted leopard distribution to the Pleistocene to gain further insights into the evolutionary history of the Javan leopard. Our data confirmed that Javan leopards are evolutionarily distinct from other Asian leopards, and that they have been present on Java since the Middle Pleistocene. Species distribution projections suggest that Java was likely colonized via a Malaya-Java land bridge that by-passed Sumatra, as suitable conditions for leopards during Pleistocene glacial periods were restricted to northern and western Sumatra. As fossil evidence supports the presence of leopards on Sumatra at the beginning of the Late Pleistocene, our projections are consistent with a scenario involving the extinction of leopards on Sumatra as a consequence of the Toba super volcanic eruption (similar to 74kya). The impact of this eruption was minor on Java, suggesting that leopards managed to survive here. Currently, only a few hundred leopards still live in the wild and only about 50 are managed in captivity. Therefore, this unique and distinctive subspecies requires urgent, concerted conservation efforts, integrating insitu and ex situ conservation management activities in a One Plan Approach to species conservation management.}, language = {en} } @article{WimmelbacherBoernke2014, author = {Wimmelbacher, Matthias and B{\"o}rnke, Frederik}, title = {Redox activity of thioredoxin z and fructokinase-like protein 1 is dispensable for autotrophic growth of Arabidopsis thaliana}, series = {Journal of experimental botany}, volume = {65}, journal = {Journal of experimental botany}, number = {9}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-0957}, doi = {10.1093/jxb/eru122}, pages = {2405 -- 2413}, year = {2014}, abstract = {Redox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C(105/106)A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, our data support a model in which TRX z and FLN1 are essential structural components of the PEP complex and their redox activity might only play a role in the fine tuning of PEP function.}, language = {en} } @article{WinckRianoPachonSommeretal.2012, author = {Winck, Flavia V. and Riano-Pachon, Diego M. and Sommer, Frederik and Rupprecht, Jens and M{\"u}ller-R{\"o}ber, Bernd}, title = {The nuclear proteome of the green alga Chlamydomonas reinhardtii}, series = {Proteomics}, volume = {12}, journal = {Proteomics}, number = {1}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1615-9853}, doi = {10.1002/pmic.201000782}, pages = {95 -- 100}, year = {2012}, abstract = {Nuclear proteins play a central role in regulating gene expression. Their identification is important for understanding how the nuclear repertoire changes over time under different conditions. Nuclear proteins are often underrepresented in proteomic studies due to the frequently low abundance of proteins involved in regulatory processes. So far, only few studies describing the nuclear proteome of plant species have been published. Recently, the genome sequence of the unicellular green alga Chlamydomonas reinhardtii has been obtained and annotated, allowing the development of further detailed studies for this organism. However, a detailed description of its nuclear proteome has not been reported so far. Here, we present an analysis of the nuclear proteome of the sequenced Chlamydomonas strain cc503. Using LC-MS/MS, we identified 672 proteins from nuclei isolates with a maximum 1\% peptide spectrum false discovery rate. Besides well-known proteins (e.g. histones), transcription factors and other transcriptional regulators (e.g. tubby and HMG) were identified. The presence of protein motifs in nuclear proteins was investigated by computational tools, and specific over-represented protein motifs were identified. This study provides new insights into the complexity of the nuclear environment and reveals novel putative protein targets for further studies of nuclear mechanisms.}, language = {en} } @article{WinckArvidssonMauricioRianoPachonetal.2013, author = {Winck, Flavia Vischi and Arvidsson, Samuel Janne and Mauricio Riano-Pachon, Diego and Hempel, Sabrina and Koseska, Aneta and Nikoloski, Zoran and Urbina Gomez, David Alejandro and Rupprecht, Jens and M{\"u}ller-R{\"o}ber, Bernd}, title = {Genome-wide identification of regulatory elements and reconstruction of gene regulatory networks of the green alga chlamydomonas reinhardtii under carbon deprivation}, series = {PLoS one}, volume = {8}, journal = {PLoS one}, number = {11}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0079909}, pages = {16}, year = {2013}, abstract = {The unicellular green alga Chlamydomonas reinhardtii is a long-established model organism for studies on photosynthesis and carbon metabolism-related physiology. Under conditions of air-level carbon dioxide concentration [CO2], a carbon concentrating mechanism (CCM) is induced to facilitate cellular carbon uptake. CCM increases the availability of carbon dioxide at the site of cellular carbon fixation. To improve our understanding of the transcriptional control of the CCM, we employed FAIRE-seq (formaldehyde-assisted Isolation of Regulatory Elements, followed by deep sequencing) to determine nucleosome-depleted chromatin regions of algal cells subjected to carbon deprivation. Our FAIRE data recapitulated the positions of known regulatory elements in the promoter of the periplasmic carbonic anhydrase (Cah1) gene, which is upregulated during CCM induction, and revealed new candidate regulatory elements at a genome-wide scale. In addition, time series expression patterns of 130 transcription factor (TF) and transcription regulator (TR) genes were obtained for cells cultured under photoautotrophic condition and subjected to a shift from high to low [CO2]. Groups of co-expressed genes were identified and a putative directed gene-regulatory network underlying the CCM was reconstructed from the gene expression data using the recently developed IOTA (inner composition alignment) method. Among the candidate regulatory genes, two members of the MYB-related TF family, Lcr1 (Low-CO2 response regulator 1) and Lcr2 (Low-CO2 response regulator 2), may play an important role in down-regulating the expression of a particular set of TF and TR genes in response to low [CO2]. The results obtained provide new insights into the transcriptional control of the CCM and revealed more than 60 new candidate regulatory genes. Deep sequencing of nucleosome-depleted genomic regions indicated the presence of new, previously unknown regulatory elements in the C. reinhardtii genome. Our work can serve as a basis for future functional studies of transcriptional regulator genes and genomic regulatory elements in Chlamydomonas.}, language = {en} } @article{WinckKwasniewskiWienkoopetal.2011, author = {Winck, Flavia Vischi and Kwasniewski, Miroslaw and Wienkoop, Stefanie and M{\"u}ller-R{\"o}ber, Bernd}, title = {An optimized method for the isolation of nuclei from chlamydomas Reinhardtii (Chlorophyceae)}, series = {Journal of phycology}, volume = {47}, journal = {Journal of phycology}, number = {2}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0022-3646}, doi = {10.1111/j.1529-8817.2011.00967.x}, pages = {333 -- 340}, year = {2011}, abstract = {The cell nucleus harbors a large number of proteins involved in transcription, RNA processing, chromatin remodeling, nuclear signaling, and ribosome assembly. The nuclear genome of the model alga Chlamydomonas reinhardtii P. A. Dang. was recently sequenced, and many genes encoding nuclear proteins, including transcription factors and transcription regulators, have been identified through computational discovery tools. However, elucidating the specific biological roles of nuclear proteins will require support from biochemical and proteomics data. Cellular preparations with enriched nuclei are important to assist in such analyses. Here, we describe a simple protocol for the isolation of nuclei from Chlamydomonas, based on a commercially available kit. The modifications done in the original protocol mainly include alterations of the differential centrifugation parameters and detergent-based cell lysis. The nuclei-enriched fractions obtained with the optimized protocol show low contamination with mitochondrial and plastid proteins. The protocol can be concluded within only 3 h, and the proteins extracted can be used for gel-based and non-gel-based proteomic approaches.}, language = {en} } @article{WinklerHeinken2007, author = {Winkler, Eckart and Heinken, Thilo}, title = {Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L.}, issn = {0304-3800}, year = {2007}, abstract = {The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas is based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within 1m2. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of population-pattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sum of squares. These sums of squares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25cm×25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sum of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1-2m was indispensable for explaining the observed population spread that led to distances of at most 8mfrom population origin within 3 years. Projections of population development over four additional years gave a diffusion-like increase of population area without any "outposts". This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism.}, language = {en} } @article{WischkeBaehrRachevaetal.2018, author = {Wischke, Christian and Baehr, Elen and Racheva, Miroslava and Heuchel, Matthias and Weigel, Thomas and Lendlein, Andreas}, title = {Surface immobilization strategies for tyrosinase as biocatalyst applicable to polymer network synthesis}, series = {MRS Advances}, volume = {3}, journal = {MRS Advances}, number = {63}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {2059-8521}, doi = {10.1557/adv.2018.630}, pages = {3875 -- 3881}, year = {2018}, abstract = {Enzymes have recently attracted increasing attention in material research based on their capacity to catalyze the conversion of polymer-bound moieties for synthesizing polymer networks, particularly bulk hydrogels. hi this study. the surface immobilization of a relevant enzyme. mushroom tyrosinase, should be explored using glass as model surface. In a first step. the glass support was functionalized with silanes to introduce either amine or carboxyl groups, as confirmed e.g. by X-ray photoelectron spectroscopy. By applying glutaraldehyde and EDC/NHS chemistry, respectively, surfaces have been activated for subsequent successful coupling of tyrosinase. Via protein hydrolysis and amino acid characterization by HPLC, the quantity of bound tyrosinase was shown to correspond to a full surface coverage. Based on the visualized enzymatic conversion of a test substrate at the glass support. the functionalized surfaces may be explored for surface-associated material synthesis in the future.}, language = {en} } @article{WisselManackBrainin2013, author = {Wissel, J{\"o}rg and Manack, Aubrey and Brainin, Michael}, title = {Toward an epidemiology of poststroke spasticity}, series = {Neurology : official journal of the American Academy of Neurology}, volume = {80}, journal = {Neurology : official journal of the American Academy of Neurology}, number = {1}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0028-3878}, pages = {S13 -- S19}, year = {2013}, abstract = {Poststroke spasticity (PSS)-related disability is emerging as a significant health issue for stroke survivors. There is a need for predictors and early identification of PSS in order to minimize complications and maladaptation from spasticity. Reviewing the literature on stroke and upper motor neuron syndrome, spasticity, contracture, and increased muscle tone measured with the Modified Ashworth Scale and the Tone Assessment Scale provided data on the dynamic time course of PSS. Prevalence estimates of PSS were highly variable, ranging from 4\% to 42.6\%, with the prevalence of disabling spasticity ranging from 2\% to 13\%. Data on phases of the PSS continuum revealed evidence of PSS in 4\% to 27\% of those in the early time course (1-4 weeks poststroke), 19\% to 26.7\% of those in the postacute phase (1-3 months poststroke), and 17\% to 42.6\% of those in the chronic phase (>3 months poststroke). Data also identified key risk factors associated with the development of spasticity, including lower Barthel Index scores, severe degree of paresis, stroke-related pain, and sensory deficits. Although such indices could be regarded as predictors of PSS and thus enable early identification and treatment, the different measures of PSS used in those studies limit the strength of the findings. To optimize evaluation in the different phases of care, the best possible assessment of PSS would make use of a combination of indicators for clinical impairment, motor performance, activity level, quality of life, and patient-reported outcome measures. Applying these recommended measures, as well as increasing our knowledge of the physiologic predictors of PSS, will enable us to perform clinical and epidemiologic studies that will facilitate identification and early, multimodal treatment.}, language = {en} } @article{WittBornhorstMitzeetal.2017, author = {Witt, B. and Bornhorst, Julia and Mitze, H. and Ebert, Franziska and Meyer, S. and Francesconi, Kevin A. and Schwerdtle, Tanja}, title = {Arsenolipids exert less toxicity in a human neuron astrocyte co-culture as compared to the respective monocultures}, series = {Metallomics : integrated biometal science}, volume = {9}, journal = {Metallomics : integrated biometal science}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1756-5901}, doi = {10.1039/c7mt00036g}, pages = {442 -- 446}, year = {2017}, abstract = {Arsenic-containing hydrocarbons (AsHCs), natural products found in seafood, have recently been shown to exert toxic effects in human neurons. In this study we assessed the toxicity of three AsHCs in cultured human astrocytes. Due to the high cellular accessibility and substantial toxicity observed astrocytes were identified as further potential brain target cells for arsenolipids. Thereby, the AsHCs exerted a 5-19-fold higher cytotoxicity in astrocytes as compared to arsenite. Next we compared the toxicity of the arsenicals in a co-culture model of the respective human astrocytes and neurons. Notably the AsHCs did not show any substantial toxic effects in the co-culture, while arsenite did. The arsenic accessibility studies indicated that in the co-culture astrocytes protect neurons against cellular arsenic accumulation especially after incubation with arsenolipids. In summary, these data underline the importance of the glial-neuron interaction when assessing the in vitro neurotoxicity of new unclassified metal species.}, language = {en} } @article{WittZanorMuellerRoeber2004, author = {Witt, Isabell and Zanor, Maria Ines and M{\"u}ller-R{\"o}ber, Bernd}, title = {Transcription factor function search : how do individual factors regulate agronomical important processes in plants? (Subproject A)}, isbn = {3-00-011587-0}, year = {2004}, language = {en} } @article{WitzelAbuRishaAlbersetal.2020, author = {Witzel, Katja and Abu Risha, Marua and Albers, Philip and B{\"o}rnke, Frederik and Hanschen, Franziska S.}, title = {Corrigendum : Identification and characterization of three epithiospecifier protein isoforms in Brassica oleracea / Witzel, Katja; Abu Risha, Marua; Albers, Philip; B{\"o}rnke, Frederike; Hanschen, Franziska S. - Lausanne: Frontiers Media, 2019. - Frontiers in plant science : FPLS. - 10 (2019) art. 1552. - doi: 10.3389/fpls.2019.01552}, series = {Frontiers in plant science : FPLS}, volume = {11}, journal = {Frontiers in plant science : FPLS}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2020.00523}, pages = {2}, year = {2020}, language = {en} } @article{WitzelAbuRishaAlbersetal.2019, author = {Witzel, Katja and Abu Risha, Marua and Albers, Philip and B{\"o}rnke, Frederik and Hanschen, Franziska S.}, title = {Identification and Characterization of Three Epithiospecifier Protein Isoforms in Brassica oleracea}, series = {Frontiers in plant science}, volume = {10}, journal = {Frontiers in plant science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2019.01552}, pages = {14}, year = {2019}, abstract = {Glucosinolates present in Brassicaceae play a major role in herbivory defense. Upon tissue disruption, glucosinolates come into contact with myrosinase, which initiates their breakdown to biologically active compounds. Among these, the formation of epithionitriles is triggered by the presence of epithiospecifier protein (ESP) and a terminal double bond in the glucosinolate side chain. One ESP gene is characterized in the model plant Arabidopsis thaliana (AtESP; At1g54040.2). However, Brassica species underwent genome triplication since their divergence from the Arabidopsis lineage. This indicates the presence of multiple ESP isoforms in Brassica crops that are currently poorly characterized. We identified three B. oleracea ESPs, specifically BoESP1 (LOC106296341), BoESP2 (LOC106306810), and BoESP3 (LOC106325105) based on in silico genome analysis. Transcript and protein abundance were assessed in shoots and roots of four B. oleracea vegetables, namely broccoli, kohlrabi, white, and red cabbage, because these genotypes showed a differential pattern for the formation of glucosinolate hydrolysis products as well for their ESP activity. BoESP1 and BoESP2 were expressed mainly in shoots, while BoESP3 was abundant in roots. Biochemical characterization of heterologous expressed BoESP isoforms revealed different substrate specificities towards seven glucosinolates: all isoforms showed epithiospecifier activity on alkenyl glucosinolates, but not on non-alkenyl glucosinolates. The pH-value differently affected BoESP activity: while BoESP1 and BoESP2 activities were optimal at pH 6-7, BoESP3 activity remained relatively stable from pH 4 to 7. In order test their potential for the in vivo modification of glucosinolate breakdown, the three isoforms were expressed in A. thaliana Hi-0, which lacks AtESP expression, and analyzed for the effect on their respective hydrolysis products. The BoESPs altered the hydrolysis of allyl glucosinolate in the A. thaliana transformants to release 1-cyano-2,3-epithiopropane and reduced formation of the corresponding 3-butenenitrile and allyl isothiocyanate. Plants expressing BoESP2 showed the highest percentage of released epithionitriles. Given these results, we propose a model for isoform-specific roles of B. oleracea ESPs in glucosinolate breakdown.}, language = {en} } @article{WojcikCeulemansGaedke2021, author = {Wojcik, Laurie Anne and Ceulemans, Ruben and Gaedke, Ursula}, title = {Functional diversity buffers the effects of a pulse perturbation on the dynamics of tritrophic food webs}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {22}, publisher = {John Wiley \& Sons, Inc.}, address = {Hoboken (New Jersey)}, issn = {2045-7758}, doi = {10.1002/ece3.8214}, pages = {15639 -- 15663}, year = {2021}, abstract = {Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: This loss may hamper ecosystems' ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. We investigated the effects of functional diversity on the robustness, that is, resistance, resilience, and elasticity, using a tritrophic—and thus more realistic—plankton food web model. We compared a non-adaptive food chain with no diversity within the individual trophic levels to a more diverse food web with three adaptive trophic levels. The species fitness differences were balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience, and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occurred. Importantly, we found that a more diverse food web was generally more resistant and resilient but its elasticity was context-dependent. Particularly, functional diversity reduced the probability of a regime shift toward a non-desirable alternative state. The basal-intermediate interaction consistently determined the robustness against a nutrient pulse despite the complex influence of the shape and type of the dynamical attractors. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience, and potentially elasticity as functional diversity declines.}, language = {en} } @article{WolffGastEversetal.2021, author = {Wolff, Martin and Gast, Klaus and Evers, Andreas and Kurz, Michael and Pfeiffer-Marek, Stefania and Sch{\"u}ler, Anja and Seckler, Robert and Thalhammer, Anja}, title = {A Conserved Hydrophobic Moiety and Helix-Helix Interactions Drive the Self-Assembly of the Incretin Analog Exendin-4}, series = {Biomolecules}, volume = {11}, journal = {Biomolecules}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2218-273X}, doi = {10.3390/biom11091305}, pages = {20}, year = {2021}, abstract = {Exendin-4 is a pharmaceutical peptide used in the control of insulin secretion. Structural information on exendin-4 and related peptides especially on the level of quaternary structure is scarce. We present the first published association equilibria of exendin-4 directly measured by static and dynamic light scattering. We show that exendin-4 oligomerization is pH dependent and that these oligomers are of low compactness. We relate our experimental results to a structural hypothesis to describe molecular details of exendin-4 oligomers. Discussion of the validity of this hypothesis is based on NMR, circular dichroism and fluorescence spectroscopy, and light scattering data on exendin-4 and a set of exendin-4 derived peptides. The essential forces driving oligomerization of exendin-4 are helix-helix interactions and interactions of a conserved hydrophobic moiety. Our structural hypothesis suggests that key interactions of exendin-4 monomers in the experimentally supported trimer take place between a defined helical segment and a hydrophobic triangle constituted by the Phe22 residues of the three monomeric subunits. Our data rationalize that Val19 might function as an anchor in the N-terminus of the interacting helix-region and that Trp25 is partially shielded in the oligomer by C-terminal amino acids of the same monomer. Our structural hypothesis suggests that the Trp25 residues do not interact with each other, but with C-terminal Pro residues of their own monomers.}, language = {en} } @article{WolffSchuelerGastetal.2020, author = {Wolff, Martin and Sch{\"u}ler, Anja and Gast, Klaus and Seckler, Robert and Evers, Andreas and Pfeiffer-Marek, Stefania and Kurz, Michael and Nagel, Norbert and Haack, Torsten and Wagner, Michael and Thalhammer, Anja}, title = {Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains}, series = {Molecular pharmaceutics}, volume = {17}, journal = {Molecular pharmaceutics}, number = {3}, publisher = {American Chemical Society}, address = {Washington}, issn = {1543-8384}, doi = {10.1021/acs.molpharmaceut.9b01195}, pages = {965 -- 978}, year = {2020}, abstract = {Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.}, language = {en} } @article{WolffSchuelerGastetal.2020, author = {Wolff, Martin and Sch{\"u}ler, Anja and Gast, Klaus and Seckler, Robert and Evers, Andreas and Pfeiffer-Marek, Stefania and Kurz, Michael and Nagel, Norbert and Haack, Torsten and Wagner, Michael and Thalhammer, Anja}, title = {Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains}, series = {Molecular pharmaceutics}, volume = {17}, journal = {Molecular pharmaceutics}, number = {3}, publisher = {American Chemical Society}, address = {Washington}, issn = {1543-8384}, doi = {10.1021/acs.molpharmaceut.9b01195}, pages = {965 -- 978}, year = {2020}, abstract = {Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.}, language = {en} } @article{WolffZhangHaagenDeckeretal.2017, author = {Wolff, Martin and Zhang-Haagen, Bo and Decker, Christina and Barz, Bogdan and Schneider, Mario and Biehl, Ralf and Radulescu, Aurel and Strodel, Birgit and Willbold, Dieter and Nagel-Steger, Luitgard}, title = {A beta 42 pentamers/hexamers are the smallest detectable oligomers in solution}, series = {Scientific reports}, volume = {7}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-017-02370-3}, pages = {13}, year = {2017}, language = {en} } @article{Wollenberger1995, author = {Wollenberger, Ursula}, title = {Electrochemical biosensors - ways to improve sensor performance}, year = {1995}, language = {en} } @article{WollenbergerDrungilieneStoeckleinetal.1996, author = {Wollenberger, Ursula and Drungiliene, A. and St{\"o}cklein, Walter F. M. and Kulys, J. and Scheller, Frieder W.}, title = {Direct electrocatalytic determination of dissolved peroxidases}, year = {1996}, language = {en} } @article{WollenbergerHintscheScheller1995, author = {Wollenberger, Ursula and Hintsche, R. and Scheller, Frieder W.}, title = {Biosensors for analytical microsystems}, year = {1995}, language = {en} } @article{WollenbergerLisdatScheller1997, author = {Wollenberger, Ursula and Lisdat, Fred and Scheller, Frieder W.}, title = {Enzymatic substrade recycling electrodes}, year = {1997}, language = {en} } @article{WollenbergerNeumann1997, author = {Wollenberger, Ursula and Neumann, B.}, title = {Quinoprotein glucose dehydrogenase modified carbon paste electrode for detection of phenolic compounds}, year = {1997}, language = {en} } @article{WollenbergerNeumannRiedeletal.1994, author = {Wollenberger, Ursula and Neumann, B. and Riedel, K. and Scheller, Frieder W.}, title = {Enzyme and microbial sensors for phosphate, phenols, pesticides and peroxides}, year = {1994}, language = {en} } @article{WollenbergerNeumannScheller1998, author = {Wollenberger, Ursula and Neumann, B. and Scheller, Frieder W.}, title = {Development of a biomimetic alkane sensor f}, year = {1998}, language = {en} } @article{WollenbergerNeumannScheller1993, author = {Wollenberger, Ursula and Neumann, B. and Scheller, Frieder W.}, title = {Enzyme and microbial sensors for environmental Monitoring}, year = {1993}, language = {en} } @article{WollenbergerScheller1993, author = {Wollenberger, Ursula and Scheller, Frieder W.}, title = {Enzyme activation for activator and enzyme activity measurement}, year = {1993}, language = {en} } @article{WollenbergerSchubertPfeifferetal.1996, author = {Wollenberger, Ursula and Schubert, Florian and Pfeiffer, Dorothea and Scheller, Frieder W.}, title = {Recycling sensors based on kinases : proceedings of Mosbach Symposion on Biochemical Technology}, year = {1996}, language = {en} } @article{WollenbergerSchubertPfeifferetal.1993, author = {Wollenberger, Ursula and Schubert, Florian and Pfeiffer, Dorothea and Scheller, Frieder W.}, title = {Enhancing biosensor performance using multienzyme systems}, year = {1993}, language = {en} } @article{WoltersBittmannKummer2005, author = {Wolters, Steffen and Bittmann, Felix and Kummer, Volker}, title = {The first subfossil records of Urtica kioviensis Rogow. and their consequences for palaeoecological interpretations}, year = {2005}, abstract = {Among plant remains from Mesolithic layers dating from 9249 to 7779 B.C. at the excavation site of Friesack IV in north-eastern Germany, nutlets of Urtica kioviensis were identified. Morphological studies have shown that they clearly differed from all other European Urtica species investigated. In contrast, pollen morphological investigations revealed only slight differences between the central European Urtica species, which could hardly have been noticed during routine or normal pollen analyses. The records of U. kioviensis nutlets are the first subfossil finds reported and prove the indigenous status of this taxon in north-eastern Germany. The records are discussed in the context of the overall species spectrum of the Mesolithic layers and consequences for the interpretation of pollen analytical studies concerning human impact are pointed out}, language = {en} } @article{WongEkkabutMiettinenDiasetal.2010, author = {Wong-Ekkabut, Jirasak and Miettinen, Markus S. and Dias, Christiano and Karttunen, Mikko}, title = {Static charges cannot drive a continuous flow of water molecules through a carbon nanotube}, issn = {1748-3387}, doi = {10.1038/nnano.2010.152}, year = {2010}, language = {en} } @article{WonkeWallschlaeger2009, author = {Wonke, Gundula and Wallschl{\"a}ger, Hans-Dieter}, title = {Song dialects in the yellowhammer Emberiza citrinella : bioacoustic variation between and within dialects}, issn = {0021-8375}, doi = {10.1007/s10336-008-0326-6}, year = {2009}, abstract = {The yellowhammer Emberiza citrinella is a common European bird that sings in dialects that for decades have been distinguished by the existence of one single element (called a "specific''). In this study we looked into other possibilities for dialect discrimination, measuring 24 different variables. For the first time, multivariate statistics were used to discriminate dialect in yellowhammer song. Two similar dialects (XlB and XsB) that are not clearly defined in the literature were studied. Statistics incorporated (1) all variables, ( 2) no variables of "specific'' elements, and (3) no variables under the influence of these "specific'' variables. Multivariate statistics support dialect discrimination by ear and confirmed that only one element in yellowhammer song characterises dialect. In addition, we looked for local differences within two dialects and found that one local observation area showed a higher separation than the other sites (Meck1). However, as yet there is insufficient evidence for the existence of a new subdialect.}, language = {en} } @article{WoodPoreeDreyeretal.2006, author = {Wood, C. C. and Poree, Fabien and Dreyer, Ingo and Koehler, G. J. and Udvardi, M. K.}, title = {Mechanisms of ammonium transport, accumulation, and retention in ooyctes and yeast cells expressing Arabidopsis AtAMT1; 1}, doi = {10.1016/j.febslet.2006.06.026}, year = {2006}, abstract = {Ammonium is a primary source of N for plants, so knowing how it is transported, stored, and assimilated in plant cells is important for rational approaches to optimise N-use in agriculture. Electrophysiological studies of Arabidopsis AtAMT1;1 expressed in oocytes revealed passive, Delta psi-driven transport of NH4+ through this protein. Expression of AtAMT1;1 in a novel yeast mutant defective in endogenous ammonium transport and vacuolar acidification supported the above mechanism for AtAMT1;1 and revealed a central role for acid vacuoles in storage and retention of ammonia in cells. These results highlight the mechanistic differences between plant AMT proteins and related transporters in bacteria and animal cells, and suggest novel strategies to enhance nitrogen use efficiency in agriculture. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved}, language = {en} } @article{WrightAmesMitchelll2016, author = {Wright, Justin P. and Ames, Gregory M. and Mitchelll, Rachel M.}, title = {The more things change, the more they stay the same? When is trait variability important for stability of ecosystem function in a changing environment}, series = {Philosophical transactions of the Royal Society of London : B, Biological sciences}, volume = {371}, journal = {Philosophical transactions of the Royal Society of London : B, Biological sciences}, publisher = {Royal Society}, address = {London}, issn = {0962-8436}, doi = {10.1098/rstb.2015.0272}, pages = {7}, year = {2016}, abstract = {The importance of intraspecific trait variability for community dynamics and ecosystem functioning has been underappreciated. There are theoretical reasons for predicting that species that differ in intraspecific trait variability will also differ in their effects on ecosystem functioning, particularly in variable environments. We discuss whether species with greater trait variability are likely to exhibit greater temporal stability in their population dynamics, and under which conditions this might lead to stability in ecosystem functioning. Resolving this requires us to consider several questions. First, are species with high levels of variation for one trait equally variable in others? In particular, is variability in response and effects traits typically correlated? Second, what is the relative contribution of local adaptation and phenotypic plasticity to trait variability? If local adaptation dominates, then stability in function requires one of two conditions: (i) individuals of appropriate phenotypes present in the environment at high enough frequencies to allow for populations to respond rapidly to the changing environment, and (ii) high levels of dispersal and gene flow. While we currently lack sufficient information on the causes and distribution of variability in functional traits, filling in these key data gaps should increase our ability to predict how changing biodiversity will alter ecosystem functioning.}, language = {en} } @article{WronskiApioPlath2006, author = {Wronski, Torsten and Apio, Ann and Plath, Martin}, title = {The communicatory significance of localised defecation sites in bushbuck (Tragelaphus scriptus)}, doi = {10.1007/s00265-006-0174-4}, year = {2006}, abstract = {Like several other mammals, bushbuck (Tragelaphus scriptus) deposit faeces in specific localised defecation sites (LDS). A previous study has ruled out a function of LDS in the context of parasite avoidance. In this study, we investigated the communicatory significance of LDS. In a free ranging population, we tested whether LDS serve to demarcate home ranges, and/or if LDS are used for communication in a non-territorial context. In both sexes, LDS increased significantly in number towards the periphery of individual home ranges. However, the distribution pattern of LDS, as revealed by a nearest-neighbour mapping technique (nearest distances between LDS), did not support the idea that LDS serve home range/territory-demarcation because LDS did not follow a pattern of minimal nearest-neighbour distances along the margins of home ranges. We found females to urinate more often in LDS than males. Notably, information transfer was most frequent between sending (urinating or defecating) females and receiving/responding males (urination or defecation at places where a female had previously signalled). Our results suggest that LDS mainly serve for inter- sexual communication in bushbuck}, language = {en} } @article{WronskiApioPlath2009, author = {Wronski, Torsten and Apio, Ann and Plath, Martin}, title = {Absence of a dominance hierarchy confirms territorial organization in male bushbuck (Tragelaphus scriptus Pallas, 1766)}, issn = {0141-6707}, doi = {10.1111/j.1365-2028.2007.00876.x}, year = {2009}, abstract = {It has been suggested that all species of spiral-horned antelopes (Tragelaphini) lack territoriality. Furthermore, some authors suggested that bushbuck (Tragelpahus scriptus) males form dominance hierarchies. In this study, we investigated the dominance relationships in two groups of free-ranging bushbuck males in Queen Elizabeth National Park, Uganda. Adult males dominated young-adult bachelors and subadult males, but no distinct dominance relationships were found among adult males. Landau's index of linearity revealed no linear dominance hierarchy in the study populations. Our results support the idea that adult males are territorial, and overt aggression is directed almost exclusively towards bachelors that challenge territory holders.}, language = {en} } @article{WronskiApioPlath2006, author = {Wronski, Torsten and Apio, Ann and Plath, Martin}, title = {Activity patterns of bushbuck (Tragelaphus scriptus) in Queen Elizabeth National Park}, series = {Behavioural processes}, volume = {73}, journal = {Behavioural processes}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0376-6357}, doi = {10.1016/j.beproc.2006.08.003}, pages = {333 -- 341}, year = {2006}, abstract = {Activity patterns and time budgets of bushbuck (Tragelaphus scriptus) were studied in a free-ranging population in Queen Elizabeth National Park, Uganda from August 2000 to January 2002. We investigated differences in activity patterns in relation to daytime, season, sun radiation, moonlight, age and sex. Bushbuck were found to show peak activities around sunrise and at dawn. No difference in the mean activity rates was found between the dry and wet season. Daytime activity was not predicted by differences in sun radiation, nor was nighttime activity predicted by the presence or absence of moonlight. We found the activity of adult territorial males to be strongly positively correlated with that of females, whereas the activity of young-adult non-territorial males was not significantly correlated with the activity of females. This suggests that young-adult males shift their peak activity to phases when adult territorial males are less active.}, language = {en} } @article{WronskiApioPlathetal.2009, author = {Wronski, Torsten and Apio, Ann and Plath, Martin and Averbeck, Christiane}, title = {Do ecotypes of bushbuck differ in grouping patterns?}, issn = {0873-9749}, doi = {10.1007/s10211-009-0058-5}, year = {2009}, abstract = {Grouping patterns within the genus Tragelaphus suggest that species inhabiting open areas tend to live in larger groups, while species preferring dense habitats live solitarily or in small family groups. We asked if similar variation would be concealed in the within-species variation of bushbuck (Tragelaphus scriptus). Recent molecular phylogeographic analyses revealed several locally adapted forms of bushbuck in different ecoregions on the African continent. We compared group sizes of south-eastern bushbuck (Tragelaphus sylvaticus) among six different populations ("ecotypes"). To date, most data on the social organization of bushbuck have been collected from only one population in Queen Elizabeth National Park (QENP) in Uganda. This particular population, however, inhabits an unusual-comparatively open-habitat type, while bushbuck otherwise inhabit dense habitats, leaving doubt whether data collected in QENP are representative of the entire species. We, therefore, compared grouping patterns between ecotypes inhabiting rather open habitats (e.g., dianae and haywoodi) and ecotypes occupying rather dense habitats (e.g., massaicus and ornatus). In bachelor groups and in all-female (spinster) groups, single sightings were the most frequent "group type" in all populations examined. We detected no significant difference among ecotypes in relative frequencies of group size categories in the case of bachelor groups. Spinster group sizes were slightly (albeit significantly) smaller in QENP than in all other areas. Moreover, a comparison of two areas inside (low human pursuit) and outside Lake Mburo National Park (high hunting pressure) in Uganda revealed no significant difference in grouping patterns in response to human pursuit (as reported for impala [Aepyceros melampus] inhabiting the same area). Altogether, our results suggest that group sizes in bushbuck are not dependent on the habitat type they inhabit; neither does human nuisance have an impact on grouping patterns. Hence, an "almost solitary" lifestyle appears to be a characteristic of the entire taxon.}, language = {en} } @article{WronskiApioWankeretal.2006, author = {Wronski, Torsten and Apio, Ann and Wanker, R and Plath, Martin}, title = {Behavioural repertoire of the bushbuck (Tragelaphus scriptus): agonistic interactions, mating behaviour and parent-offspring relations}, doi = {10.1007/s10164-005-0186-y}, year = {2006}, abstract = {A free-ranging bushbuck (Tragelaphus scriptus) population was observed over a period of 3 years, thereby enabling a detailed description of the behavioural repertoire of this widespread but barely investigated solitary African antelope species. Agonistic and submissive behaviour patterns are described, among them several hitherto un- described behaviour patterns - such as "escorting", where territorial males guide intruders to the periphery of their territory - and "push-up position", an extreme form of submissive behaviour. Furthermore, we report on behaviour patterns of males and females during mating as well as on behaviour patterns of parents directed towards their offspring. Again, we describe a hitherto unknown behaviour: the protection of calves by adult males, which may be a socio-positive behaviour directed towards their offspring led by kin selection}, language = {en} } @article{WronskiTiedemannApioetal.2006, author = {Wronski, Torsten and Tiedemann, Ralph and Apio, Ann and Plath, Martin}, title = {Cover, food, competitors and individual densities within bushbuck Tragelaphus scriptus female clan home ranges}, year = {2006}, abstract = {We examined factors predicting female densities within the common home ranges of related females ("clans") in bushbuck Tragelaphus scriptus Pallas, 1776. In this species, each female forms an individual home range, but the home ranges of matrilineal clan members strongly overlap. We found female densities to increase in areas with high canopy cover. Moreover, individual home range sizes tended to decrease with increasing cover. Food plant availability and intruder pressure by two heterospecific competitors did not significantly affect female densities. Apparently, canopy cover is the major limited resource in this species. A possible explanation is that both adult bushbuck and - even more markedly - fawns hide from predators in dense vegetation, in particular in thicket clumps and coalescences. The study shows an effect of habitat properties (eg sufficient canopy cover) on a within-population level in bushbuck, where female densities differ even among proximate clan areas}, language = {en} } @article{WronskiWacherHammondetal.2010, author = {Wronski, Torsten and Wacher, Timothy and Hammond, Robert L. and Winney, Bruce and Hundertmark, Kris J. and Blacket, Mark J. and Mohammed, Osama B. and Flores, Benito and Omer, Sawsan A. and Macasero, William and Plath, Martin and Tiedemann, Ralph and Bleidorn, Christoph}, title = {Two reciprocally monophyletic mtDNA lineages elucidate the taxonomic status of Mountain gazelles (Gazella gazella)}, issn = {1477-2000}, doi = {10.1080/14772001003613192}, year = {2010}, abstract = {Mountain gazelles (Gazella gazella) rank among the most critically endangered mammals on the Arabian Peninsula. Past conservation efforts have been plagued by confusion about the phylogenetic relationship among various 'phenotypically discernable' populations, and even the question of species boundaries was far from being certain. This lack of knowledge has had a direct impact on conservation measures, especially ex situ breeding programmes, hampering the assignment of captive stocks to potential conservation units. Here, we provide a phylogenetic framework, based on the analysis of mtDNA sequences (360 bp cytochrome b and 213 bp Control Region) of 126 individuals collected from the wild throughout the Arabian Peninsula and from captive stocks. Our analyses revealed two reciprocally monophyletic genetic lineages within the presumed species Gazella gazella: one 'northern clade' on the Golan Heights (Israel/Syrian border) and one genetically diverse larger clade from the rest of the Arabian Peninsula including the Arava Valley (Negev, Israel). Applying the Strict Phylogenetic Species Concept (sensu Mishler \& Theriot, 2000) allows assigning species status to these two major clades.}, language = {en} } @article{WuAlluGarapatietal.2012, author = {Wu, Anhui and Allu, Annapurna Devi and Garapati, Prashanth and Siddiqui, Hamad and Dortay, Hakan and Zanor, Maria-Ines and Asensi-Fabado, Maria Amparo and Munne-Bosch, Sergi and Antonio, Carla and Tohge, Takayuki and Fernie, Alisdair R. and Kaufmann, Kerstin and Xue, Gang-Ping and M{\"u}ller-R{\"o}ber, Bernd and Balazadeh, Salma}, title = {Jungbrunnen1, a reactive oxygen species-responsive NAC transcription factor, regulates longevity in arabidopsis}, series = {The plant cell}, volume = {24}, journal = {The plant cell}, number = {2}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {1040-4651}, doi = {10.1105/tpc.111.090894}, pages = {482 -- 506}, year = {2012}, abstract = {The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H2O2)-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1 overexpression strongly delays senescence, dampens intracellular H2O2 levels, and enhances tolerance to various abiotic stresses, whereas in jub1-1 knockdown plants, precocious senescence and lowered abiotic stress tolerance are observed. A JUB1 binding site containing a RRYGCCGT core sequence is present in the promoter of DREB2A, which plays an important role in abiotic stress responses. JUB1 transactivates DREB2A expression in mesophyll cell protoplasts and transgenic plants and binds directly to the DREB2A promoter. Transcriptome profiling of JUB1 overexpressors revealed elevated expression of several reactive oxygen species-responsive genes, including heat shock protein and glutathione S-transferase genes, whose expression is further induced by H2O2 treatment. Metabolite profiling identified elevated Pro and trehalose levels in JUB1 overexpressors, in accordance with their enhanced abiotic stress tolerance. We suggest that JUB1 constitutes a central regulator of a finely tuned control system that modulates cellular H2O2 level and primes the plants for upcoming stress through a gene regulatory network that involves DREB2A.}, language = {en} } @article{WuHanRodriguezSillkeetal.2019, author = {Wu, Hao and Han, Yijie and Rodriguez Sillke, Yasmina and Deng, Hongzhang and Siddiqui, Sophiya and Treese, Christoph and Schmidt, Franziska and Friedrich, Marie and Keye, Jacqueline and Wan, Jiajia and Qin, Yue and K{\"u}hl, Anja A. and Qin, Zhihai and Siegmund, Britta and Glauben, Rainer}, title = {Lipid droplet-dependent fatty acid metabolism controls the immune suppressive phenotype of tumor-associated macrophages}, series = {EMBO molecular medicine}, volume = {11}, journal = {EMBO molecular medicine}, number = {11}, publisher = {Wiley}, address = {Hoboken}, issn = {1757-4676}, doi = {10.15252/emmm.201910698}, pages = {17}, year = {2019}, abstract = {Tumor-associated macrophages (TAMs) promote tumor growth and metastasis by suppressing tumor immune surveillance. Herein, we provide evidence that the immunosuppressive phenotype of TAMs is controlled by long-chain fatty acid metabolism, specifically unsaturated fatty acids, here exemplified by oleate. Consequently, en-route enriched lipid droplets were identified as essential organelles, which represent effective targets for chemical inhibitors to block in vitro polarization of TAMs and tumor growth in vivo. In line, analysis of human tumors revealed that myeloid cells infiltrating colon cancer but not gastric cancer tissue indeed accumulate lipid droplets. Mechanistically, our data indicate that oleate-induced polarization of myeloid cells depends on the mammalian target of the rapamycin pathway. Thus, our findings reveal an alternative therapeutic strategy by targeting the pro-tumoral myeloid cells on a metabolic level.}, language = {en} } @article{WuStoddartWuertzKozaketal.2017, author = {Wu, Yabin and Stoddart, Martin J. and Wuertz-Kozak, Karin and Grad, Sibylle and Alini, Mauro and Ferguson, Stephen J.}, title = {Hyaluronan supplementation as a mechanical regulator of cartilage tissue development under joint-kinematic-mimicking loading}, series = {Interface : journal of the Royal Society}, volume = {14}, journal = {Interface : journal of the Royal Society}, publisher = {Royal Society}, address = {London}, issn = {1742-5689}, doi = {10.1098/rsif.2017.0255}, pages = {9}, year = {2017}, language = {en} } @article{WuWollenbergerHofrichteretal.2011, author = {Wu, Yunhua and Wollenberger, Ursula and Hofrichter, Martin and Ullrich, Rene and Scheibner, Katrin and Scheller, Frieder W.}, title = {Direct electron transfer of Agrocybe aegerita peroxygenase at electrodes modified with chitosan-capped Au nanoparticles and its bioelectrocatalysis to aniline}, series = {Sensors and actuators : B, Chemical}, volume = {160}, journal = {Sensors and actuators : B, Chemical}, number = {1}, publisher = {Elsevier}, address = {Lausanne}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.09.090}, pages = {1419 -- 1426}, year = {2011}, abstract = {Three different sizes of chitosan-capped Au nanoparticles were synthesized and were used to incorporate Agrocybe aegerita peroxygenase (AaeAPO) onto the surface of glassy carbon electrode. The direct electron transfer of AaeAPO was achieved in all films. The highest amount of electroactive enzyme and highest electron transfer rate constant k(s) of AaeAPO were obtained in the film with the smallest size of chitosan-capped Au nanoparticles. In anaerobic solutions, quasi-reversible oxidation and reduction are obtained with a formal potential of -0.280V vs. Ag/AgCl 1 M KCl in 100 mM (pH 7.0) PBS at scan rate of 1 V s(-1). Bioelectrocatalytic reduction currents can be obtained with the AaeAPO-modified electrode on addition of hydrogen peroxide. This reaction was suppressed when sodium azide, an inhibitor of AaeAPO, was present. Furthermore, the peroxide-dependent conversion of aniline was characterized and it was found that a polymer product via p-aminophenol is formed. And the AaeAPO biosensor was applied to determine aniline and p-aminophenol.}, language = {en} } @article{WulfRujner2011, author = {Wulf, Monika and Rujner, Hendrik}, title = {A GIS-based method for the reconstruction of the late eighteenth century forest vegetation in the Prignitz region (NE Germany)}, series = {Landscape ecology}, volume = {26}, journal = {Landscape ecology}, number = {2}, publisher = {Springer}, address = {Dordrecht}, issn = {0921-2973}, doi = {10.1007/s10980-010-9555-1}, pages = {153 -- 168}, year = {2011}, abstract = {Our goal was to reconstruct the late eighteenth century forest vegetation of the Prignitz region (NE Germany) at a scale of 1:50,000. We also wanted to relate the historical forest vegetation to the actual and potential natural vegetation. For these purposes, we selected 15 woody species and transferred relevant data found in historical records from various sources together with the recent localities of (very) old individuals belonging to these woody species into ArcView GIS. Following multi-step data processing including the generation of a point density layer using a moving window with kernel estimation and derivation of vegetation units applying Boolean algebra rules together with information on site conditions, we derived 17 forest communities corresponding to the potential natural vegetation. We were able to reconstruct the historical forest vegetation for 90\% of the forest area ca. 1780. Only two of the 17 forest communities covered large parts of the forested area. The oak forest with Agrostis capillaris covered about 44\% of the total forest area, and alder forests on fenland made up about 37\%. Oak-hornbeam forests with Stellaria holostea comprised slightly less than 6\% of the forest area, while all other forest communities comprised less than 1\%. The historical forest vegetation is more similar to the potential forest vegetation and quite different from the actual forest vegetation because coniferous tree species currently cover approximately two-thirds of the actual forest area. The most beneficial result of this study is the map of high-resolution historical vegetation units that may serve as the basis for various further studies, e.g., modelling long-term changes in biodiversity at the landscape scale.}, language = {en} } @article{WurzbacherAttermeyerKettneretal.2017, author = {Wurzbacher, Christian and Attermeyer, Katrin and Kettner, Marie Therese and Flintrop, Clara and Warthmann, Norman and Hilt, Sabine and Grossart, Hans-Peter and Monaghan, Michael T.}, title = {DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom}, series = {Environmental microbiology reports}, volume = {9}, journal = {Environmental microbiology reports}, publisher = {Wiley}, address = {Hoboken}, issn = {1758-2229}, doi = {10.1111/1758-2229.12540}, pages = {383 -- 388}, year = {2017}, abstract = {Most studies of aquatic plankton focus on either macroscopic or microbial communities, and on either eukaryotes or prokaryotes. This separation is primarily for methodological reasons, but can overlook potential interactions among groups. Here we tested whether DNA metabarcoding of unfractionated water samples with universal primers could be used to qualitatively and quantitatively study the temporal dynamics of the total plankton community in a shallow temperate lake. Significant changes in the relative proportions of normalized sequence reads of eukaryotic and prokaryotic plankton communities over a 3-month period in spring were found. Patterns followed the same trend as plankton estimates measured using traditional microscopic methods. The bloom of a conditionally rare bacterial taxon belonging to Arcicella was characterized, which rapidly came to dominate the whole lake ecosystem and would have remained unnoticed without metabarcoding. The data demonstrate the potential of universal DNA metabarcoding applied to unfractionated samples for providing a more holistic view of plankton communities.}, language = {en} } @article{WurzbacherFuchsAttermeyeretal.2017, author = {Wurzbacher, Christian and Fuchs, Andrea and Attermeyer, Katrin and Frindte, Katharina and Grossart, Hans-Peter and Hupfer, Michael and Casper, Peter and Monaghan, Michael T.}, title = {Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment}, series = {Microbiome}, volume = {5}, journal = {Microbiome}, publisher = {BioMed Central}, address = {London}, issn = {2049-2618}, doi = {10.1186/s40168-017-0255-9}, pages = {16}, year = {2017}, abstract = {Background: Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods: We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to Cs-137 dating and was sectioned into layers 1-4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results: Community beta-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5-14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions: By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper "replacement horizon" is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower "depauperate horizon" is characterized by low taxonomic richness, more stable "low-energy" conditions, and a dominance of enigmatic Archaea.}, language = {en} } @article{WurzbacherRoeselRychlaetal.2014, author = {Wurzbacher, Christian and Roesel, Stefan and Rychla, Anna and Grossart, Hans-Peter}, title = {Importance of saprotrophic freshwater fungi for pollen degradation}, series = {PLoS one}, volume = {9}, journal = {PLoS one}, number = {4}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0094643}, pages = {12}, year = {2014}, abstract = {Fungi and bacteria are the major organic matter (OM) decomposers in aquatic ecosystems. While bacteria are regarded as primary mineralizers in the pelagic zone of lakes and oceans, fungi dominate OM decomposition in streams and wetlands. Recent findings indicate that fungal communities are also active in lakes, but little is known about their diversity and interactions with bacteria. Therefore, the decomposer niche overlap of saprotrophic fungi and bacteria was studied on pollen (as a seasonally recurring source of fine particulate OM) by performing microcosm experiments with three different lake types. Special emphasis was placed on analysis of fungal community composition and diversity. We hypothesized that (I) pollen select for small saprotrophic fungi and at the same time for typical particle-associated bacteria; (II) fungal communities form specific free-living and attached sub-communities in each lake type; (III) the ratio between fungi or bacteria on pollen is controlled by the lake's chemistry. Bacteria-to-fungi ratios were determined by quantitative PCR (qPCR), and bacterial and fungal diversity were studied by clone libraries and denaturing gradient gel electrophoresis (DGGE) fingerprints. A protease assay was used to identify functional differences between treatments. For generalization, systematic differences in bacteria-to-fungi ratios were analyzed with a dataset from the nearby Baltic Sea rivers. High abundances of Chytridiomycota as well as occurrences of Cryptomycota and yeast-like fungi confirm the decomposer niche overlap of saprotrophic fungi and bacteria on pollen. As hypothesized, microbial communities consistently differed between the lake types and exhibited functional differences. Bacteria-to-fungi ratios correlated well with parameters such as organic carbon and pH. The importance of dissolved organic carbon and nitrogen for bacteria-to-fungi ratios was supported by the Baltic Sea river dataset. Our findings highlight the fact that carbon-to-nitrogen ratios may also control fungal contributions to OM decomposition in aquatic ecosystems.}, language = {en} } @article{WurzbacherSalkaGrossart2012, author = {Wurzbacher, Christian and Salka, Ivette and Grossart, Hans-Peter}, title = {Environmental actinorhodopsin expression revealed by a new in situ filtration and fixation sampler}, series = {Environmental microbiology reports}, volume = {4}, journal = {Environmental microbiology reports}, number = {5}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1758-2229}, doi = {10.1111/j.1758-2229.2012.00350.x}, pages = {491 -- 497}, year = {2012}, abstract = {Freshwater Actinobacteria are an important and dominant group of bacterioplankton in most temperate freshwater systems. Recently, metagenomic studies discovered rhodopsin-like protein-coding sequences present in Actinobacteria which could be a decisive hint for their success in freshwater ecosystems. We analysed the diversity of actinorhodopsin (ActR) in Lake Stechlin (northern Germany) and assessed the actR expression profile during a diurnal cycle. We obtained 85 positive actR clones which could be subsequently grouped to 17 operational taxonomic units assuming a 90\% sequence similarity. The phylogenetic analysis points to a close relationship of all obtained sequences to the acI lineage of Actinobacteria, forming six independent clusters. For the first time, we followed in situ transcription of actR in Lake Stechlin revealing a rather constitutive circadian gene expression. For analysing in situ expression patterns of functional genes in aquatic ecosystems, such as actR, we invented a new in situ filtration and fixation sampler (IFFS). The IFFS enables the representative investigation of microbial transcriptomes in any aquatic ecosystem at all water depths. The IFFS sampler is simple and inexpensive, and we provide all engineering plans for an easy rebuild. Consequently, our IFFS is suitable to reliably study expression of any known functional gene of any aquatic microorganism.}, language = {en} } @article{WurzbacherWarthmannBourneetal.2016, author = {Wurzbacher, Christian and Warthmann, Norman and Bourne, Elizabeth Charlotte and Attermeyer, Katrin and Allgaier, Martin and Powell, Jeff R. and Detering, Harald and Mbedi, Susan and Grossart, Hans-Peter and Monaghan, Michael T.}, title = {High habitat-specificity in fungal communities in oligo-mesotrophic, temperate Lake Stechlin (North-East Germany)}, series = {MycoKeys}, volume = {41}, journal = {MycoKeys}, publisher = {Pensoft Publ.}, address = {Sofia}, issn = {1314-4057}, doi = {10.3897/mycokeys.16.9646}, pages = {17 -- 44}, year = {2016}, abstract = {Freshwater fungi are a poorly studied ecological group that includes a high taxonomic diversity. Most studies on aquatic fungal diversity have focused on single habitats, thus the linkage between habitat heterogeneity and fungal diversity remains largely unexplored. We took 216 samples from 54 locations representing eight different habitats in the meso-oligotrophic, temperate Lake Stechlin in North-East Germany. These included the pelagic and littoral water column, sediments, and biotic substrates. We performed high throughput sequencing using the Roche 454 platform, employing a universal eukaryotic marker region within the large ribosomal subunit (LSU) to compare fungal diversity, community structure, and species turnover among habitats. Our analysis recovered 1027 fungal OTUs (97\% sequence similarity). Richness estimates were highest in the sediment, biofilms, and benthic samples (189-231 OTUs), intermediate in water samples (42-85 OTUs), and lowest in plankton samples (8 OTUs). NMDS grouped the eight studied habitats into six clusters, indicating that community composition was strongly influenced by turnover among habitats. Fungal communities exhibited changes at the phylum and order levels along three different substrate categories from littoral to pelagic habitats. The large majority of OTUs (> 75\%) could not be classified below the order level due to the lack of aquatic fungal entries in public sequence databases. Our study provides a first estimate of lake-wide fungal diversity and highlights the important contribution of habitat heterogeneity to overall diversity and community composition. Habitat diversity should be considered in any sampling strategy aiming to assess the fungal diversity of a water body.}, language = {en} } @article{WusterChirioTrapeetal.2018, author = {Wuster, Wolfgang and Chirio, Laurent and Trape, Jean-Francois and Ineich, Ivan and Jackson, Kate and Greenbaum, Eli and Barron, Cesar and Kusamba, Chifundera and Nagy, Zoltan T. and Storey, Richard and Hall, Cara and Wuster, Catharine E. and Barlow, Axel and Broadley, Donald G.}, title = {Integration of nuclear and mitochondrial gene sequences and morphology reveals unexpected diversity in the forest cobra (Naja melanoleuca) species complex in Central and West Africa (Serpentes: Elapidae)}, series = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, volume = {4455}, journal = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, number = {1}, publisher = {Magnolia Press}, address = {Auckland}, issn = {1175-5326}, doi = {10.11646/zootaxa.4455.1.3}, pages = {68 -- 98}, year = {2018}, abstract = {Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and morphology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich \& Wuster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio \& Wuster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited understanding of tropical African biodiversity, hindering our ability to conserve it effectively.}, language = {en} } @article{WutkeBeneckeSandovalCastellanosetal.2016, author = {Wutke, Saskia and Benecke, Norbert and Sandoval-Castellanos, Edson and D{\"o}hle, Hans-J{\"u}rgen and Friederich, Susanne and Gonzalez Soto, Javier Esteban and Hallsson, Jon Hallsteinn and Hofreiter, Michael and Lougas, Lembi and Magnell, Ola and Morales-Muniz, Arturo and Orlando, Ludovic and Palsdottir, Albina Hulda and Reissmann, Monika and Ruttkay, Matej and Trinks, Alexandra and Ludwig, Arne}, title = {Spotted phenotypes in horses lost attractiveness in the Middle Ages}, series = {Scientific reports}, volume = {6}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/srep38548}, pages = {9}, year = {2016}, abstract = {Horses have been valued for their diversity of coat colour since prehistoric times; this is especially the case since their domestication in the Caspian steppe in similar to 3,500 BC. Although we can assume that human preferences were not constant, we have only anecdotal information about how domestic horses were influenced by humans. Our results from genotype analyses show a significant increase in spotted coats in early domestic horses (Copper Age to Iron Age). In contrast, medieval horses carried significantly fewer alleles for these phenotypes, whereas solid phenotypes (i.e., chestnut) became dominant. This shift may have been supported because of (i) pleiotropic disadvantages, (ii) a reduced need to separate domestic horses from their wild counterparts, (iii) a lower religious prestige, or (iv) novel developments in weaponry. These scenarios may have acted alone or in combination. However, the dominance of chestnut is a remarkable feature of the medieval horse population.}, language = {en} } @article{WutkeSandovalCastellanosBeneckeetal.2018, author = {Wutke, Saskia and Sandoval-Castellanos, Edson and Benecke, Norbert and D{\"o}hle, Hans-J{\"u}rgen and Friederich, Susanne and Gonzalez, Javier and Hofreiter, Michael and Lougas, Lembi and Magnell, Ola and Malaspinas, Anna-Sapfo and Morales-Muniz, Arturo and Orlando, Ludovic and Reissmann, Monika and Trinks, Alexandra and Ludwig, Arne}, title = {Decline of genetic diversity in ancient domestic stallions in Europe}, series = {Science Advances}, volume = {4}, journal = {Science Advances}, number = {4}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {2375-2548}, doi = {10.1126/sciadv.aap9691}, pages = {7}, year = {2018}, abstract = {Present-day domestic horses are immensely diverse in their maternally inherited mitochondrial DNA, yet they show very little variation on their paternally inherited Y chromosome. Although it has recently been shown that Y chromosomal diversity in domestic horses was higher at least until the Iron Age, when and why this diversity disappeared remain controversial questions. We genotyped 16 recently discovered Y chromosomal single-nucleotide polymorphisms in 96 ancient Eurasian stallions spanning the early domestication stages (Copper and Bronze Age) to the Middle Ages. Using this Y chromosomal time series, which covers nearly the entire history of horse domestication, we reveal how Y chromosomal diversity changed over time. Our results also show that the lack of multiple stallion lineages in the extant domestic population is caused by neither a founder effect nor random demographic effects but instead is the result of artificial selection-initially during the Iron Age by nomadic people from the Eurasian steppes and later during the Roman period. Moreover, the modern domestic haplotype probably derived from another, already advantageous, haplotype, most likely after the beginning of the domestication. In line with recent findings indicating that the Przewalski and domestic horse lineages remained connected by gene flow after they diverged about 45,000 years ago, we present evidence for Y chromosomal introgression of Przewalski horses into the gene pool of European domestic horses at least until medieval times.}, language = {en} } @article{WoelflTittelZippeletal.2000, author = {W{\"o}lfl, S. and Tittel, J{\"o}rg and Zippel, Barbara and Kringel, R.}, title = {Occurrence of an algal mass development in an acidic (pH 2.5), iron and aluminium-rich coal mining pond}, year = {2000}, language = {en} } @article{WuestenhagenLukasMuelleretal.2020, author = {W{\"u}stenhagen, Doreen Anja and Lukas, Phil and M{\"u}ller, Christian and Aubele, Simone A. and Hildebrandt, Jan-Peter and Kubick, Stefan}, title = {Cell-free synthesis of the hirudin variant 1 of the blood-sucking leech Hirudo medicinalis}, series = {Scientific reports}, volume = {10}, journal = {Scientific reports}, number = {1}, publisher = {Macmillan Publishers Limited, part of Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-020-76715-w}, pages = {13}, year = {2020}, abstract = {Synthesis and purification of peptide drugs for medical applications is a challenging task. The leech-derived factor hirudin is in clinical use as an alternative to heparin in anticoagulatory therapies. So far, recombinant hirudin is mainly produced in bacterial or yeast expression systems. We describe the successful development and application of an alternative protocol for the synthesis of active hirudin based on a cell-free protein synthesis approach. Three different cell lysates were compared, and the effects of two different signal peptide sequences on the synthesis of mature hirudin were determined. The combination of K562 cell lysates and the endogenous wild-type signal peptide sequence was most effective. Cell-free synthesized hirudin showed a considerably higher anti-thrombin activity compared to recombinant hirudin produced in bacterial cells.}, language = {en} } @article{XiangGaoYuetal.2014, author = {Xiang, Hai and Gao, Jianqiang and Yu, Baoquan and Zhou, Hui and Cai, Dawei and Zhang, Youwen and Chen, Xiaoyong and Wang, Xi and Hofreiter, Michael and Zhao, Xingbo}, title = {Early Holocene chicken domestication in northern China}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {49}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1411882111}, pages = {17564 -- 17569}, year = {2014}, abstract = {Chickens represent by far the most important poultry species, yet the number, locations, and timings of their domestication have remained controversial for more than a century. Here we report ancient mitochondrial DNA sequences from the earliest archaeological chicken bones from China, dating back to similar to 10,000 B.P. The results clearly show that all investigated bones, including the oldest from the Nanzhuangtou site, are derived from the genus Gallus, rather than any other related genus, such as Phasianus. Our analyses also suggest that northern China represents one region of the earliest chicken domestication, possibly dating as early as 10,000 y B.P. Similar to the evidence from pig domestication, our results suggest that these early domesticated chickens contributed to the gene pool of modern chicken populations. Moreover, our results support the idea that multiple members of the genus Gallus, specifically Gallus gallus and Gallus sonneratii contributed to the gene pool of the modern domestic chicken. Our results provide further support for the growing evidence of an early mixed agricultural complex in northern China.}, language = {en} } @article{XiaoLiuWangetal.2020, author = {Xiao, Shangbin and Liu, Liu and Wang, Wei and Lorke, Andreas and Woodhouse, Jason Nicholas and Grossart, Hans-Peter}, title = {A Fast-Response Automated Gas Equilibrator (FaRAGE) for continuous in situ measurement of CH4 and CO2 dissolved in water}, series = {Hydrology and earth system sciences : HESS}, volume = {24}, journal = {Hydrology and earth system sciences : HESS}, number = {7}, publisher = {European Geosciences Union (EGU) ; Copernicus}, address = {Munich}, issn = {1027-5606}, doi = {10.5194/hess-24-3871-2020}, pages = {3871 -- 3880}, year = {2020}, abstract = {Biogenic greenhouse gas emissions, e.g., of methane (CH4) and carbon dioxide (CO2) from inland waters, contribute substantially to global warming. In aquatic systems, dissolved greenhouse gases are highly heterogeneous in both space and time. To better understand the biological and physical processes that affect sources and sinks of both CH4 and CO2, their dissolved concentrations need to be measured with high spatial and temporal resolution. To achieve this goal, we developed the Fast-Response Automated Gas Equilibrator (FaRAGE) for real-time in situ measurement of dissolved CH4 and CO2 concentrations at the water surface and in the water column. FaRAGE can achieve an exceptionally short response time (t(95\%) = 12 s when including the response time of the gas analyzer) while retaining an equilibration ratio of 62.6\% and a measurement accuracy of 0.5\% for CH4. A similar performance was observed for dissolved CO2 (t(95\%) = 10 s, equilibration ratio 67.1 \%). An equilibration ratio as high as 91.8\% can be reached at the cost of a slightly increased response time (16 s). The FaRAGE is capable of continuously measuring dissolved CO2 and CH4 concentrations in the nM-to-submM (10(-9)-10(-3) mol L-1) range with a detection limit of subnM (10(-10) mol L-1), when coupling with a cavity ring-down greenhouse gas analyzer (Picarro GasScouter). FaRAGE allows for the possibility of mapping dissolved concentration in a "quasi" three-dimensional manner in lakes and provides an inexpensive alternative to other commercial gas equilibrators. It is simple to operate and suitable for continuous monitoring with a strong tolerance for suspended particles. While the FaRAGE is developed for inland waters, it can be also applied to ocean waters by tuning the gas-water mixing ratio. The FaRAGE is easily adapted to suit other gas analyzers expanding the range of potential applications, including nitrous oxide and isotopic composition of the gases.}, language = {en} } @article{XieTangWollenbergeretal.1997, author = {Xie, B. and Tang, X. and Wollenberger, Ursula and Johansson, G. and Gorton, Lo and Scheller, Frieder W. and Danielsson, B.}, title = {Hybrid biosensor for simultaneous electrochemical and thermal detection}, year = {1997}, language = {en} } @article{XieTechritzHaebeletal.2005, author = {Xie, J. and Techritz, S. and Haebel, Sophie and Horn, A. and Neitzel, H. and Klose, J. and Schuelke, M.}, title = {A two-dimensional electrophoretic map of human mitochondrial proteins from immortalized lymphoblastoid cell lines: a prerequisite to study mitochondrial disorders in patients}, issn = {1615-9853}, year = {2005}, abstract = {Mitochondrial diseases may be caused by numerous mutations that alter proteins of the respiratory chain and of other metabolic pathways in the mitochondrium. For clinicians this disease group poses a considerable diagnostic challenge due to ambiguous genotype-phenotype relationships. Until now, only 30 \% of the mitochondriopathies can be diagnosed at the molecular level. We therefore need a new diagnostic tool that offers a wide view on the mitochondrial proteins. Here, we present a method to generate a high-resolution, large-gel two-dimensional gel electrophoretic (2-DE) map of a purified fraction of mitochondrial proteins from Epstein-Barr virus-immortalized lymphoblastoid cell line (LCL). LCLs can be easily obtained from patients and control subjects in a routine clinical setting. They often express the biochemical phenotype and can be cultured to high cell numbers, sufficient to gain enough purified material for 2- DE. In total we identified 166 mitochondrial proteins. Thirteen proteins were earlier not known to be of mitochondrial origin. Thirty-nine proteins were associated with human diseases ranging from respiratory chain enzyme deficiencies to disorders of P-oxidation and amino acid metabolism. This 2-DE map is intended to be the first step to diagnose mitochondrial diseases at the proteomic level}, language = {en} } @article{XuGiannettiSugiyamaetal.2022, author = {Xu, Huizhen and Giannetti, Alessandro and Sugiyama, Yuki and Zheng, Wenna and Schneider, Ren{\´e} and Watanabe, Yoichiro and Oda, Yoshihisa and Persson, Staffan}, title = {Secondary cell wall patterning-connecting the dots, pits and helices}, series = {Open biology}, volume = {12}, journal = {Open biology}, number = {5}, publisher = {Royal Society}, address = {London}, issn = {2046-2441}, doi = {10.1098/rsob.210208}, pages = {18}, year = {2022}, abstract = {All plant cells are encased in primary cell walls that determine plant morphology, but also protect the cells against the environment. Certain cells also produce a secondary wall that supports mechanically demanding processes, such as maintaining plant body stature and water transport inside plants. Both these walls are primarily composed of polysaccharides that are arranged in certain patterns to support cell functions. A key requisite for patterned cell walls is the arrangement of cortical microtubules that may direct the delivery of wall polymers and/or cell wall producing enzymes to certain plasma membrane locations. Microtubules also steer the synthesis of cellulose-the load-bearing structure in cell walls-at the plasma membrane. The organization and behaviour of the microtubule array are thus of fundamental importance to cell wall patterns. These aspects are controlled by the coordinated effort of small GTPases that probably coordinate a Turing's reaction-diffusion mechanism to drive microtubule patterns. Here, we give an overview on how wall patterns form in the water-transporting xylem vessels of plants. We discuss systems that have been used to dissect mechanisms that underpin the xylem wall patterns, emphasizing the VND6 and VND7 inducible systems, and outline challenges that lay ahead in this field.}, language = {en} } @article{XuBrearleyLinetal.2005, author = {Xu, J. and Brearley, C. A. and Lin, W. H. and Wang, Y. and Ye, R. and M{\"u}ller-R{\"o}ber, Bernd and Xu, Z. H. and Xue, H. W.}, title = {A role of Arabidopsis inositol polyphosphate kinase, AtIPK2 alpha, in pollen germination and root growth}, issn = {0032-0889}, year = {2005}, abstract = {Inositol polyphosphates, such as inositol trisphosphate, are pivotal intracellular signaling molecules in eukaryotic cells. In higher plants the mechanism for the regulation of the type and the level of these signaling molecules is poorly understood. In this study we investigate the physiological function of an Arabidopsis (Arabidopsis thaliana) gene encoding inositol polyphosphate kinase (AtIPK2alpha), which phosphorylates inositol 1,4,5-trisphosphate successively at the D-6 and D-3 positions, and inositol 1,3,4,5-tetrakisphosphate at D-6, resulting in the generation of inositol 1,3,4,5,6-pentakisphosphate. Semiquantitative reverse transcription-PCR and promoter-beta-glucuronidase reporter gene analyses showed that AtIPK2alpha is expressed in various tissues, including roots and root hairs, stem, leaf, pollen grains, pollen tubes, the flower stigma, and siliques. Transgenic Arabidopsis plants expressing the AtIPK2alpha antisense gene under its own promoter were generated. Analysis of several independent transformants exhibiting strong reduction in AtIPK2alpha transcript levels showed that both pollen germination and pollen tube growth were enhanced in the antisense lines compared to wild-type plants, especially in the presence of nonoptimal low Ca2+ concentrations in the culture medium. Furthermore, root growth and root hair development were also stimulated in the antisense lines, in the presence of elevated external Ca2+ concentration or upon the addition of EGTA. In addition, seed germination and early seedling growth was stimulated in the antisense lines. These observations suggest a general and important role of AtIPK2alpha, and hence inositol polyphosphate metabolism, in the regulation of plant growth most likely through the regulation of calcium signaling, consistent with the well-known function of inositol trisphosphate in the mobilization of intracellular calcium stores}, language = {en} } @article{XuRazaghiMoghadamNikoloski2021, author = {Xu, Rudan and Razaghi-Moghadam, Zahra and Nikoloski, Zoran}, title = {Maximization of non-idle enzymes improves the coverage of the estimated maximal in vivo enzyme catalytic rates in Escherichia coli}, series = {Bioinformatics}, volume = {37}, journal = {Bioinformatics}, number = {21}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1367-4803}, doi = {10.1093/bioinformatics/btab575}, pages = {3848 -- 3855}, year = {2021}, abstract = {Motivation: Constraint-based modeling approaches allow the estimation of maximal in vivo enzyme catalytic rates that can serve as proxies for enzyme turnover numbers. Yet, genome-scale flux profiling remains a challenge in deploying these approaches to catalogue proxies for enzyme catalytic rates across organisms. Results: Here, we formulate a constraint-based approach, termed NIDLE-flux, to estimate fluxes at a genome-scale level by using the principle of efficient usage of expressed enzymes. Using proteomics data from Escherichia coli, we show that the fluxes estimated by NIDLE-flux and the existing approaches are in excellent qualitative agreement (Pearson correlation > 0.9). We also find that the maximal in vivo catalytic rates estimated by NIDLE-flux exhibits a Pearson correlation of 0.74 with in vitro enzyme turnover numbers. However, NIDLE-flux results in a 1.4-fold increase in the size of the estimated maximal in vivo catalytic rates in comparison to the contenders. Integration of the maximum in vivo catalytic rates with publically available proteomics and metabolomics data provide a better match to fluxes estimated by NIDLE-flux. Therefore, NIDLE-flux facilitates more effective usage of proteomics data to estimate proxies for kcatomes.}, language = {en} } @article{XuWollenbergerQianetal.2013, author = {Xu, Xuan and Wollenberger, Ursula and Qian, Jing and Lettau, Katrin and Jung, Christiane and Liu, Songqin}, title = {Electrochemically driven biocatalysis of the oxygenase domain of neuronal nitric oxide synthase in indium tin oxide nanoparticles/polyvinyl alcohol nanocomposite}, series = {Bioelectrochemistry : an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry ; official journal of the Bioelectrochemical Society}, volume = {94}, journal = {Bioelectrochemistry : an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry ; official journal of the Bioelectrochemical Society}, number = {47}, publisher = {Elsevier}, address = {Lausanne}, issn = {1567-5394}, doi = {10.1016/j.bioelechem.2013.04.005}, pages = {7 -- 12}, year = {2013}, abstract = {Nitric oxide synthase (NOS) plays a critical role in a number of key physiological and pathological processes. Investigation of electron-transfer reactions in NOS would contribute to a better understanding of the nitric oxide (NO) synthesis mechanism. Herein, we describe an electrochemically driven catalytic strategy, using a nanocomposite that consisted of the oxygenase domain of neuronal NOS (D290nNOSoxy), indium tin oxide (ITO) nanopartides and polyvinyl alcohol (PVA). Fast direct electron transfer between electrodes and D290nNOSoxy was observed with the heterogeneous electron transfer rate constant (k(er)) of 154.8 +/- 0.1 s(-1) at the scan rate of 5 V s(-1). Moreover, the substrate IV-hydroxy-L-arginine (NHA) was used to prove the concept of electrochemically driven biocatalysis of D290nNOSoxy. In the presence of the oxygen cosubstrate and tetrahydrobiopterin (BH4) cofactor, the addition of NHA caused the decreases of both oxidation current at + 0.1 V and reduction current at potentials ranging from -0.149 V to -0.549 V vs Ag/AgCl. Thereafter, a series of control experiments such as in the absence of BH4 or D290nNOSoxy were performed. All the results demonstrated that D290nNOSoxy biocatalysis was successfully driven by electrodes in the presence of BH4 and oxygen. This novel bioelectronic system showed potential for further investigation of NOS and biosensor applications. (C) 2013 Elsevier B.V. All rights reserved.}, language = {en} } @article{XuNieWangetal.2021, author = {Xu, Xun and Nie, Yan and Wang, Weiwei and Ullah, Imran and Tung, Wing Tai and Ma, Nan and Lendlein, Andreas}, title = {Generation of 2.5D lung bud organoids from human induced pluripotent stem cells}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {79}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, number = {1}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-219111}, pages = {217 -- 230}, year = {2021}, abstract = {Human induced pluripotent stem cells (hiPSCs) are a promising cell source to generate the patient-specific lung organoid given their superior differentiation potential. However, the current 3D cell culture approach is tedious and time-consuming with a low success rate and high batch-to-batch variability. Here, we explored the establishment of lung bud organoids by systematically adjusting the initial confluence levels and homogeneity of cell distribution. The efficiency of single cell seeding and clump seeding was compared. Instead of the traditional 3D culture, we established a 2.5D organoid culture to enable the direct monitoring of the internal structure via microscopy. It was found that the cell confluence and distribution prior to induction were two key parameters, which strongly affected hiPSC differentiation trajectories. Lung bud organoids with positive expression of NKX 2.1, in a single-cell seeding group with homogeneously distributed hiPSCs at 70\% confluence (SC 70\% hom) or a clump seeding group with heterogeneously distributed cells at 90\% confluence (CL 90\% het), can be observed as early as 9 days post induction. These results suggest that a successful lung bud organoid formation with single-cell seeding of hiPSCs requires a moderate confluence and homogeneous distribution of cells, while high confluence would be a prominent factor to promote the lung organoid formation when seeding hiPSCs as clumps. 2.5D organoids generated with defined culture conditions could become a simple, efficient, and valuable tool facilitating drug screening, disease modeling and personalized medicine.}, language = {en} } @article{Xu2022, author = {Xu, Ying}, title = {Study on transport mechanism of m5C-edited mRNAs}, pages = {133}, year = {2022}, language = {en} } @article{YanFrokjarEngelbrektetal.2021, author = {Yan, Jiawei and Fr{\o}kj{\ae}r, Emil Egede and Engelbrekt, Christian and Leimk{\"u}hler, Silke and Ulstrup, Jens and Wollenberger, Ulla and Xiao, Xinxin and Zhang, Jingdong}, title = {Voltammetry and single-molecule in situ scanning tunnelling microscopy of the redox metalloenzyme human sulfite oxidase}, series = {ChemElectroChem}, volume = {8}, journal = {ChemElectroChem}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2196-0216}, doi = {10.1002/celc.202001258}, pages = {164 -- 171}, year = {2021}, abstract = {Human sulfite oxidase (hSO) is a homodimeric two-domain enzyme central in the biological sulfur cycle. A pyranopterin molybdenum cofactor (Moco) is the catalytic site and a heme b(5) group located in the N-terminal domain. The two domains are connected by a flexible linker region. Electrons produced at the Moco in sulfite oxidation, are relayed via heme b(5) to electron acceptors or an electrode surface. Inter-domain conformational changes between an open and a closed enzyme conformation, allowing "gated" electron transfer has been suggested. We first recorded cyclic voltammetry (CV) of hSO on single-crystal Au(111)-electrode surfaces modified by self-assembled monolayers (SAMs) both of a short rigid thiol, cysteamine and of a longer structurally flexible thiol, omega-amino-octanethiol (AOT). hSO on cysteamine SAMs displays a well-defined pair of voltammetric peaks around -0.207 V vs. SCE in the absence of sulfite substrate, but no electrocatalysis. hSO on AOT SAMs displays well-defined electrocatalysis, but only "fair" quality voltammetry in the absence of sulfite. We recorded next in situ scanning tunnelling spectroscopy (STS) of hSO on AOT modified Au(111)-electrodes, disclosing, a 2-5 \% surface coverage of strong molecular scale contrasts, assigned to single hSO molecules, notably with no contrast difference in the absence and presence of sulfite. In situ STS corroborated this observation with a sigmoidal tunnelling current/overpotential correlation.}, language = {en} } @article{YanFriemelAloisietal.2016, author = {Yan, Robert and Friemel, Martin and Aloisi, Claudia and Huynen, Martijn and Taylor, Ian A. and Leimk{\"u}hler, Silke and Pastore, Annalisa}, title = {The Eukaryotic-Specific ISD11 Is a Complex-Orphan Protein with Ability to Bind the Prokaryotic IscS}, series = {PLoS one}, volume = {11}, journal = {PLoS one}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0157895}, pages = {383 -- 395}, year = {2016}, abstract = {The eukaryotic protein Isd11 is a chaperone that binds and stabilizes the central component of the essential metabolic pathway responsible for formation of iron-sulfur clusters in mitochondria, the desulfurase Nfs1. Little is known about the exact role of Isd11. Here, we show that human Isd11 (ISD11) is a helical protein which exists in solution as an equilibrium between monomer, dimeric and tetrameric species when in the absence of human Nfs1 (NFS1). We also show that, surprisingly, recombinant ISD11 expressed in E. coli co-purifies with the bacterial orthologue of NFS1, IscS. Binding is weak but specific suggesting that, despite the absence of Isd11 sequences in bacteria, there is enough conservation between the two desulfurases to retain a similar mode of interaction. This knowledge may inform us on the conservation of the mode of binding of Isd11 to the desulfurase. We used evolutionary evidence to suggest Isd11 residues involved in the interaction.}, language = {en} } @article{YanFangNoecheletal.2018, author = {Yan, Wan and Fang, Liang and N{\"o}chel, Ulrich and Gould, Oliver E. C. and Behl, Marc and Kratz, Karl and Lendlein, Andreas}, title = {Investigating the roles of crystallizable and glassy switching segments within multiblock copolymer shape-memory materials}, series = {MRS Advances}, volume = {3}, journal = {MRS Advances}, number = {63}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {2059-8521}, doi = {10.1557/adv.2018.590}, pages = {3741 -- 3749}, year = {2018}, abstract = {The variation of the molecular architecture of multiblock copolymers has enabled the introduction of functional behaviour and the control of key mechanical properties. In the current study, we explore the synergistic relationship of two structural components in a shape-memory material formed of a multiblock copolymer with crystallizable poly(epsilon-caprolactone) and crystallizable polyfoligo(3S-iso-butylmorpholine-2,5-dione) segments (PCL-PIBMD). The thermal and structural properties of PCL-PIBMD films were compared with PCI.-PU and PMMD-PU investigated by means of DSC, SAXS and WARS measurements. The shape-memory properties were quantified by cyclic, thermomechanical tensile tests, where deformation strains up to 900\% were applied for programming PCL-PIBMD films at 50 degrees C. Toluene vapor treatment experiments demonstrated that the temporary shape was fixed mainly by glassy PIBMD domains at strains lower than 600\% with the PCL contribution to fixation increasing to 42 +/- 2\% at programming strains of 900\% This study into the shape-memory mechanism of PCL-PIBMD provides insight into the structure function relation in multiblock copolymers with both crystallizable and glassy switching segments.}, language = {en} } @article{YanChenKaufmann2016, author = {Yan, Wenhao and Chen, Dijun and Kaufmann, Kerstin}, title = {Efficient multiplex mutagenesis by RNA-guided Cas9 and its use in the characterization of regulatory elements in the AGAMOUS gene}, series = {Plant methods}, volume = {12}, journal = {Plant methods}, publisher = {BioMed Central}, address = {London}, issn = {1746-4811}, doi = {10.1186/s13007-016-0125-7}, pages = {1 -- 9}, year = {2016}, abstract = {Background The efficiency of multiplex editing in plants by the RNA-guided Cas9 system is limited by efficient introduction of its components into the genome and by their activity. The possibility of introducing large fragment deletions by RNA-guided Cas9 tool provides the potential to study the function of any DNA region of interest in its 'endogenous' environment. Results Here, an RNA-guided Cas9 system was optimized to enable efficient multiplex editing in Arabidopsis thaliana. We demonstrate the flexibility of our system for knockout of multiple genes, and to generate heritable large-fragment deletions in the genome. As a proof of concept, the function of part of the second intron of the flower development gene AGAMOUS in Arabidopsis was studied by generating a Cas9-free mutant plant line in which part of this intron was removed from the genome. Further analysis revealed that deletion of this intron fragment results 40 \% decrease of AGAMOUS gene expression without changing the splicing of the gene which indicates that this regulatory region functions as an activator of AGAMOUS gene expression. Conclusions Our modified RNA-guided Cas9 system offers a versatile tool for the functional dissection of coding and non-coding DNA sequences in plants.}, language = {en} }