Items 1-20 of 1299

    • Journal Article

      Microtiming Deviations and Swing Feel in Jazz 

      Datseris, George; Ziereis, Annika; Albrecht, Thorsten; Hagmayer, York; Priesemann, Viola; Geisel, Theo
      Scientific Reports 2019; 9(1): Art. 19824
      Jazz music that swings has the fascinating power to elicit a pleasant sensation of flow in listeners and the desire to synchronize body movements with the music. Whether microtiming deviations (MTDs), i.e. small timing deviations below the bar or phrase level, enhance the swing feel is highly debated in the current literature. Studies on other groove related genres did not find evidence for a positive impact of MTDs. The present study addresses jazz music and swing in particular, as there is some evidence that microtiming patterns are genre-specific. We recorded twelve piano jazz standards played by a professional pianist and manipulated the natural MTDs of the recordings in systematic ways by quantizing, expanding and inverting them. MTDs were defined with respect to a grid determined by the average swing ratio. The original and manipulated versions were presented in an online survey and evaluated by 160 listeners with various musical skill levels and backgrounds. Across pieces the quantized versions (without MTDs) were rated slightly higher and versions with expanded MTDs were rated lower with regard to swing than the original recordings. Unexpectedly, inversion had no impact on swing ratings except for two pieces. Our results suggest that naturally fluctuating MTDs are not an essential factor for the swing feel.
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    • Journal Article

      Evolutionary transitions toward pair living in nonhuman primates as stepping stones toward more complex societies 

      Kappeler, Peter M.; Pozzi, Luca
      Science Advances 2019; 5(12): Art. eaay1276
      Nonhuman primate societies vary tremendously in size and composition, but how and why evolutionary transitions among different states occurred remains highly controversial. In particular, how many times pair living evolved and the social states of the ancestors of pair- and group-living species remains contentious. We examined evolutionary transitions in primate social evolution by using new, independent categorizations of sociality and different phylogenetic hypotheses with a vastly expanded dataset. Using Bayesian phylogenetic comparative methods, we consistently found the strongest support for a model that invokes frequent transitions between solitary ancestors and pair-living descendants, with the latter giving rise to group-living species. This result was robust to systematic variation in social classification, sample size, and phylogeny. Our analyses therefore indicate that pair living was a stepping stone in the evolution of structurally more complex primate societies, a result that bolsters the role of kin selection in social evolution.
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    • Journal Article

      How to Achieve Tax Compliance by the Wealthy: A Review of the Literature and Agenda for Policy 

      Gangl, Katharina; Torgler, Benno
      Social Issues and Policy Review 2019; 14(1) p.108-151
      Tax compliance by the wealthy is relevant not only because their contributions are essential to maintain public budgets and social equality, but because their (non)compliance behavior and the perceived (un)fairness of their contributions can fuel social unrest. In this article, after giving a brief history of taxing the wealthy, we review the existing theoretical, empirical, and policy literature on their tax compliance. We discuss how and why the wealthy differ from less affluent taxpayers because of specific interrelated political, social, and psychological conditions. Understanding the psychological mechanisms that determine the tax compliance of the wealthy can provide policy insights on how to better integrate the wealthy in the tax system. Therefore, the present review is also a starting point for new policy approaches to increase tax compliance and tax morale among the wealthy.
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    • Journal Article

      Invasive lumbricid earthworms in North America—Different life histories but common dispersal? 

      Klein, Andreas; Eisenhauer, Nico; Schaefer, Ina
      Journal of Biogeography p.1-12
      Aim: Lumbricid earthworms are invasive across northern North America, caus‐ ing notable changes in forest ecosystems. During their range expansion, they en‐ countered harsher climatic conditions compared to their native ranges in short time (~400 years). This study investigated if (a) dispersal barriers, (b) climatic selection or (c) anthropogenic activities, that is fishing bait disposal, structure the dispersal of free‐living earthworm populations. Location: North America, forest habitats along former Wisconsinan glaciation line. Taxon: Lumbricus terrestris, L. rubellus. Methods: Lumbricus terrestris and L. rubellus co‐occur in the same habitats but dif‐ fer in ecology and use as fishing bait. Both species were sampled in five transects ranging from the east to the west coast of northern North America, including major dispersal barriers, three different climate zones, and bait shops near sampling loca‐ tions. Genetic diversity and structure were compared between the two species, and the presence of free‐living bait shop genotypes was assessed using four markers (COI, 16S rDNA, 12S rDNA, and H3). Results: Populations of both species were genetically diverse with some geographic structure, which was more pronounced in L. terrestris than in L. rubellus. Common haplotypes were present in all regions, but locally restricted haplotypes also oc‐ curred. Furthermore, two distinct genetic clades of L. terrestris co‐occurred only in the two most distant transects (Alberta and Minnesota). Genotypes identical to bait individuals were omnipresent in field populations of L. terrestris. Main Conclusions: Genetic diversity was high in both species, and invasive popula‐ tions represented a genetic subset of European earthworms. Geographic and climatic dispersal barriers affected the less mobile species, L. terrestris, resulting in differ‐ ences in genetic structure between the two species. Our results indicate common long‐distance dispersal vectors and vectors affecting only L. terrestris. The roles of climate and anthropogenic activities are discussed, providing additional explanations of dispersal and new insights into establishment of invasive earthworm populations.
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    • Journal Article

      The number of k-mer matches between two DNA sequences as a function of k and applications to estimate phylogenetic distances 

      Röhling, Sophie; Linne, Alexander; Schellhorn, Jendrik; Hosseini, Morteza; Dencker, Thomas; Morgenstern, Burkhard
      PLOS ONE 2020; 15(2): Art. e0228070
      We study the number Nk of length-k word matches between pairs of evolutionarily related DNA sequences, as a function of k. We show that the Jukes-Cantor distance between two genome sequences—i.e. the number of substitutions per site that occurred since they evolved from their last common ancestor—can be estimated from the slope of a function F that depends on Nk and that is affine-linear within a certain range of k. Integers kmin and kmax can be calculated depending on the length of the input sequences, such that the slope of F in the relevant range can be estimated from the values F(kmin) and F(kmax). This approach can be generalized to so-called Spaced-word Matches (SpaM), where mismatches are allowed at positions specified by a user-defined binary pattern. Based on these theoretical results, we implemented a prototype software program for alignment-free sequence comparison called Slope-SpaM. Test runs on real and simulated sequence data show that Slope-SpaM can accurately estimate phylogenetic distances for distances up to around 0.5 substitutions per position. The statistical stability of our results is improved if spaced words are used instead of contiguous words. Unlike previous alignment-free methods that are based on the number of (spaced) word matches, Slope-SpaM produces accurate results, even if sequences share only local homologies.
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    • Journal Article

      Polyclad phylogeny persists to be problematic 

      Dittmann, Isabel L.; Cuadrado, Daniel; Aguado, Maria Teresa; Noreña, Carolina; Egger, Bernhard
      Organisms Diversity & Evolution 2019; 19(4) p.585-608
      Two conflicting morphological approaches to polyclad systematics highlight the relevance of molecular data for resolving the interrelationships of Polycladida. In the present study, phylogenetic trees were reconstructed based on a short alignment of the 28S rDNA marker gene with 118 polyclad terminals (24 new) including 100 different polyclad species from 44 genera and 22 families, as well as on a combined dataset using 18S and 28S rDNA genes with 27 polyclad terminals (19 new) covering 26 different polyclad species. In both approaches, Theamatidae and Cestoplanidae were included, two families that have previously been shown to switch from Acotylea to Cotylea. Three different alignment methods were used, both with and without alignment curation by Gblocks, and all alignments were subjected to Bayesian inference and maximum likelihood tree calculations. Over all trees of the combined dataset, an extended majority-rule consensus tree had weak support for Theamatidae and Cestoplanidae as acotyleans, and also the cotylean genera Boninia, Chromyella and Pericelis appeared as acotyleans. With the most inclusive short 28S dataset, on the other hand, there is good support for the aforementioned taxa as cotyleans. Especially with the short 28S matrix, taxon sampling, outgroup selection, alignment method and curation, as well as model choice were all decisive for tree topology. Well-supported parts of the phylogeny over all trees include Pseudocerotoidea, Prosthiostomoidea, Stylochoidea, Leptoplanoidea and Cryptoceloidea, the latter three with new definitions. Unstable positions in the tree were found not only for Theamatidae, Cestoplanidae, Boninia, Chromyella and Pericelis, but also for Anonymus, Chromoplana and Cycloporus.
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    • Journal Article

      Cytoplasmic retention and degradation of a mitotic inducer enable plant infection by a pathogenic fungus 

      Bardetti, Paola; Castanheira, Sónia Marisa; Valerius, Oliver; Braus, Gerhard H; Pérez-Martín, José
      eLife 2019; 8: Art. e48943
      In the fungus Ustilago maydis, sexual pheromones elicit mating resulting in an infective filament able to infect corn plants. Along this process a G2 cell cycle arrest is mandatory. Such as cell cycle arrest is initiated upon the pheromone recognition in each mating partner, and sustained once cell fusion occurred until the fungus enter the plant tissue. We describe that the initial cell cycle arrest resulted from inhibition of the nuclear transport of the mitotic inducer Cdc25 by targeting its importin, Kap123. Near cell fusion to take place, the increase on pheromone signaling promotes Cdc25 degradation, which seems to be important to ensure the maintenance of the G2 cell cycle arrest to lead the formation of the infective filament. This way, premating cell cycle arrest is linked to the subsequent steps required for establishment of the infection. Disabling this connection resulted in the inability of fungal cells to infect plants.
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    • Journal Article

      A framework for conceptualizing dimensions of social organization in mammals 

      Prox, Lea; Farine, Damien
      Ecology and Evolution p.1-17
      Mammalian societies represent many different types of social systems. While some aspects of social systems have been extensively studied, there is little consensus on how to conceptualize social organization across species. Here, we present a framework describing eight dimensions of social organization to capture its diversity across mammalian societies. The framework uses simple information that is clearly separated from the three other aspects of social systems: social structure, care system, and mating system. By applying our framework across 208 species of all mammalian taxa, we find a rich multidimensional landscape of social organization. Correlation analysis reveals that the dimensions have relatively high independence, suggesting that social systems are able to evolve different aspects of social behavior without being tied to particular traits. Applying a clustering algorithm allows us to identify the relative importance of key dimensions on patterns of social organization. Finally, mapping mating system onto these clusters shows that social organization represents a distinct aspect of social systems. In the future, this framework will aid reporting on important aspects of natural history in species and facilitate comparative analyses, which ultimately will provide the ability to generate new insights into the primary drivers of social patterns and evolution of sociality.
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    • Journal Article

      A Fosmid-Based System for the Generation of Recombinant Cercopithecine Alphaherpesvirus 2 Encoding Reporter Genes 

      Chukhno, Ekaterina; Gärtner, Sabine; Rahman Siregar, Abdul; Mehr, Alexander; Wende, Marie; Petkov, Stoyan; Götting, Jasper; Dhingra, Akshay; Schulz, Thomas; Pöhlmann, Stefan; et al.
      Winkler, Michael
      Viruses 2019; 11(11): Art. 1026
      The transmission of Macacine alphaherpesvirus 1 (McHV-1) from macaques, the natural host, to humans causes encephalitis. In contrast, human infection with Cercopithecine alphaherpesvirus 2 (CeHV-2), a closely related alphaherpesvirus from African vervet monkeys and baboons, has not been reported and it is believed that CeHV-2 is apathogenic in humans. The reasons for the differential neurovirulence of McHV-1 and CeHV-2 have not been explored on a molecular level, in part due to the absence of systems for the production of recombinant viruses. Here, we report the generation of a fosmid-based system for rescue of recombinant CeHV-2. Moreover, we show that, in this system, recombineering can be used to equip CeHV-2 with reporter genes. The recombinant CeHV-2 viruses replicated with the same efficiency as uncloned, wt virus and allowed the identification of cell lines that are highly susceptible to CeHV-2 infection. Collectively, we report a system that allows rescue and genetic modification of CeHV-2 and likely other alphaherpesviruses. This system should aid future analysis of CeHV-2 biology.
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    • Journal Article

      Passing the Message: Representation Transfer in Modular Balanced Networks 

      Zajzon, Barna; Mahmoudian, Sepehr; Morrison, Abigail; Duarte, Renato
      Frontiers in Computational Neuroscience 2019; 13: Art. 79
      Neurobiological systems rely on hierarchical and modular architectures to carry out intricate computations using minimal resources. A prerequisite for such systems to operate adequately is the capability to reliably and efficiently transfer information across multiple modules. Here, we study the features enabling a robust transfer of stimulus representations in modular networks of spiking neurons, tuned to operate in a balanced regime. To capitalize on the complex, transient dynamics that such networks exhibit during active processing, we apply reservoir computing principles and probe the systems' computational efficacy with specific tasks. Focusing on the comparison of random feed-forward connectivity and biologically inspired topographic maps, we find that, in a sequential set-up, structured projections between the modules are strictly necessary for information to propagate accurately to deeper modules. Such mappings not only improve computational performance and efficiency, they also reduce response variability, increase robustness against interference effects, and boost memory capacity. We further investigate how information from two separate input streams is integrated and demonstrate that it is more advantageous to perform non-linear computations on the input locally, within a given module, and subsequently transfer the result downstream, rather than transferring intermediate information and performing the computation downstream. Depending on how information is integrated early on in the system, the networks achieve similar task-performance using different strategies, indicating that the dimensionality of the neural responses does not necessarily correlate with nonlinear integration, as predicted by previous studies. These findings highlight a key role of topographic maps in supporting fast, robust, and accurate neural communication over longer distances. Given the prevalence of such structural feature, particularly in the sensory systems, elucidating their functional purpose remains an important challenge toward which this work provides relevant, new insights. At the same time, these results shed new light on important requirements for designing functional hierarchical spiking networks.
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    • Journal Article

      Disruption of Arabidopsis neutral ceramidases 1 and 2 results in specific sphingolipid imbalances triggering different phytohormone‐dependent plant cell death programmes 

      Zienkiewicz, Agnieszka; Gömann, Jasmin; König, Stefanie; Herrfurth, Cornelia; Liu, Yi‐Tse; Meldau, Dorothea; Feussner, Ivo
      New Phytologist p.1-19
      Sphingolipids act as regulators of programmed cell death (PCD) and the plant defence response. The homeostasis between long-chain base (LCB) and ceramide (Cer) seems to play an important role in executions of PCD. Therefore, deciphering the role of neutral ceramidases (NCER) is crucial to identify the sphingolipid compounds that trigger and execute PCD. We performed comprehensive sphingolipid and phytohormone analyses of Arabidopsis ncer mutants, combined with gene expression profiling and microscopic analyses. While ncer1 exhibited early leaf senescence (developmentally controlled PCD - dPCD) and an increase in hydroxyceramides, ncer2 showed spontaneous cell death (pathogen-triggered PCD-like - pPCD) accompanied by an increase in LCB t18:0 at 35 d, respectively. Loss of NCER1 function resulted in accumulation of jasmonoyl-isoleucine (JA-Ile) in the leaves, whereas disruption of NCER2 was accompanied by higher levels of salicylic acid (SA) and increased sensitivity to Fumonisin B1 (FB1 ). All mutants were also found to activate plant defence pathways. These data strongly suggest that NCER1 hydrolyses ceramides whereas NCER2 functions as a ceramide synthase. Our results reveal an important role of NCER in the regulation of both dPCD and pPCD via a tight connection between the phytohormone and sphingolipid levels in these two processes.
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    • Journal Article

      Parasite burden in a short-lived chameleon, Furcifer labordi 

      Eckhardt, Falk; Strube, Christina; Mathes, Karina A.; Mutschmann, Frank; Thiesler, Hauke; Kraus, Cornelia; Kappeler, Peter M.
      International Journal for Parasitology: Parasites and Wildlife 2019; 10 p.231-240
      Life history theory predicts that species with shorter lifespan should show higher investments into growth and reproduction at the expense of immune defenses. Labord's chameleon (Furcifer labordi) is the tetrapod with the shortest known life span. To investigate to which extent immunosenescence influences the die-off of these chameleons when they are only about 6 months old, we examined the gastrointestinal-, blood- and ectoparasite burden in F. labordi in Kirindy Forest (western Madagascar) and compared them with sympatric and longer living F. cf. nicosiai. Moreover, we included data from wild F. labordi that were singly housed under ambient conditions with daily food and water supply. Gastrointestinal parasite prevalence of wild F. labordi increased dramatically during the last 3 months of their lives, which include the reproductive period. Furcifer cf. nicosiai was found to have a belated increase in gastrointestinal parasites compared to F. labordi. In F. cf. nicosiai higher prevalence of blood parasites were found, which probably result from the longer exposure to the arthropod intermediate host. Both species showed infestations with ectoparasites, which peaked in the rainy season but disappeared towards the dry season. Male F. labordi showed a significantly higher prevalence of gastrointestinal - and ectoparasites and higher intensities of coccidians and ectoparasites than females. Males of F. cf. nicosiai exhibited higher prevalence of blood- and ectoparasites, as well as higher intensities in ectoparasites. Caged individuals of both sexes showed delayed senescence, reduced parasite burden and lived longer than their wild conspecifics. Overall, the increase in the prevalence in gastrointestinal - and blood parasites towards the disappearance of the wild population of F. labordi indicates that this species invests comparatively less energy in efficient immune system function, supporting the prediction of life history theory.
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    • Journal Article

      Student Teachers’ Knowledge to Enable Problem-Solving for Sustainable Development 

      Richter-Beuschel, Lisa; Bögeholz, Susanne
      Sustainability 2020; 12(1): Art. 79
      Education is a central strategy in terms of sustainable development (SD) and can contribute to solving global challenges like biodiversity loss and climate change. Content knowledge represents one base for teaching education for sustainable development (ESD). Therefore, identifying teaching and learning prerequisites regarding SD challenges in teacher education is crucial. The focus of the paper was to assess and learn more about student teachers’ procedural knowledge regarding issues of biodiversity and climate change, by using an expert benchmark. The aims of the study are to describe and identify (i) di erences between students’ and experts’ e ectiveness estimations, (ii) di erences in bachelor and master students’ procedural knowledge, and (iii) di erences between procedural knowledge of students studying di erent ESD-relevant subjects. Student teachers at eight German universities (n = 236) evaluated the e ectiveness of solution strategies to SD challenges. The results showed high deviations in the e ectiveness estimations of experts and students and, therefore, di ering procedural knowledge. The lack of student teachers’ interdisciplinary knowledge to reduce biodiversity loss and climate change seemed to be largely independent of their study program and ESD-relevant subject. One reason for this may be the generally low number of ESD-relevant courses they attended. This study suggests further longitudinal research in order to make clear statements about changes in SD-related knowledge during teacher education.
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      Coordination Complex Formation and Redox Properties of Kynurenic and Xanthurenic Acid Can Affect Brain Tissue Homeodynamics 

      Kubicova, Lenka; Hadacek, Franz; Bachmann, Gert; Weckwerth, Wolfram; Chobot, Vladimir
      Antioxidants 2019; 8(10): Art. 476
      Reactive oxygen species (ROS) are known for their participation in various physiological and pathological processes in organisms, including ageing or degeneration. Kynurenine pathway metabolites, such as kynurenic (KYNA) or xanthurenic (XA) acid, can affect neurodegenerative diseases due to their ROS scavenging and Fe ion coordination complex formation but insights are still incomplete. Therefore, we investigated the formation and antioxidant capabilities of KYNA- and XA-Fe complexes by nano-electrospray-mass spectrometry, differential pulse voltammetry, deoxyribose degradation and FeII autoxidation assays. XA formed coordination complexes with FeII or FeIII ions and was an effective antioxidant. By contrast, only FeII-KYNA complexes could be detected. Moreover, KYNA showed no antioxidant effects in the FeCl3/ascorbic acid deoxyribose degradation assay variant and only negligible activities in the FeII autoxidation assay. Coordination complexes of Fe ions with KYNA probably stabilize KYNA in its keto tautomer form. Nevertheless, both KYNA and XA exhibited sufficient antioxidant activities in some of the employed assay variants. The results provide evidence that both have the potential to alleviate neurodegenerative diseases by helping to maintain tissue redox homeodynamics.
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      Composition, Diversity and Functional Analysis of the Modern Microbiome of the Middle Triassic Cava Superiore Beds (Monte San Giorgio, Switzerland) 

      Arif, Sania; Reitner, Joachim; Hoppert, Michael
      Scientific Reports 2019; 9(1): Art. 20394
      Organic-rich laminated shales and limestones from the Monte San Giorgio (Lugano Prealps, Switzerland) are known as famous fossil lagerstätten for excellently preserved fossils from the Middle Triassic Period. The various bituminous shales from Monte San Giorgio are thermally immature and rich in diverse organic compounds, which provide unique substrates for active soil microbial communities. We selected the Cava superior beds of the Acqua del Ghiffo site for this study. To investigate its microbial structure and diversity, contig assembly, Operational Taxonomic Units (OTUs) clustering, and rarefaction analysis were performed for bacterial 16S rDNA preparations from bituminous and non-bituminous limestone strata with the MetaAmp pipeline. Principal coordinates analysis shows that the microbial communities from the bituminous strata differ significantly from limestone samples (P < 0.05 Unifrac weighted). Moreover, metagenomic tools could also be used effectively to analyze the microbial communities shift during enrichment in specific growth media. In the nutrient-rich media, one or few taxa, mainly Proteobacteria and Firmicutes, were enriched which led to the drastic diversity loss while oligotrophic media could enrich many taxa simultaneously and sustain the richness and diversity of the inoculum. Piphillin, METAGENassist and MicrobiomeAnalyst pipeline also predicted that the Monte San Giorgio bituminous shales and oligotrophic enriched microbiomes degrade complex polycyclic aromatic hydrocarbons.
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      Desert‐like badlands and surrounding (semi‐)dry grasslands of Central Germany promote small‐scale phenotypic and genetic differentiation in Thymus praecox 

      Karbstein, Kevin; Tomasello, Salvatore; Prinz, Kathleen
      Ecology and Evolution p.1-19
      Environmental heterogeneity among sites can generate phenotypic and genetic variation facilitating differentiation and microevolution of plant populations. Badlands are desert‐like, predominantly vegetation‐poor habitats often embedded in (semi‐)dry grasslands. The desert‐like conditions of badlands demand extreme adaptation of plants, that is, phenotypic modifications in short‐term and/or natural adaptation in long‐term. However, detailed knowledge is missing about both plant phenotypic and genetic differentiation in this unique and widely occurring habitat type. The present study focused on the largest known badlands systems in Central Europe located in the “Drei Gleichen” region, a designated nature conservation area in Central Germany. Locations were suitable for this study in terms of having co‐occurring badlands and (semi‐)dry grassland habitats (sites) occupied by the pioneer plant Thymus praecox. Here, we studied the environmental preferences, morphological and functional trait variation, and genetic variation using microsatellite markers of T. praecox. Results revealed significant, mainly site‐dependent environmental, phenotypic, and genetic differentiation. In general, individuals in badlands are shorter in height and have lower patch sizes (length × width), relative growth rates, and smaller stomata. The PCA additionally unveiled slightly increased leaf robustness, trichome density, decreased stomatal conductance, fewer females, and earlier phenology in badlands. We interpret differentiation patterns as adaptive responses to light, temperature, drought, and nutrient stress conditions supported by reviewed literature. Genetic differentiation was strongest between local badlands and grassland sites, and clearly weaker among locations and between sites (in total) as indicated by GST, AMOVA, PCoA, and population structure. Our study supports the importance of small‐scale microhabitat conditions as a driver of microevolutionary processes, and the population's need for sufficient phenotypic plasticity and genetic resources to deal with environmental changes. We demonstrated that badlands are an appropriate model system for testing plant response to extreme habitats and that more research is needed on these fascinating landscapes.
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      A novel role for Ets4 in axis specification and cell migration in the spider Parasteatoda tepidariorum 

      Pechmann, Matthias; Benton, Matthew A; Kenny, Nathan J; Posnien, Nico; Roth, Siegfried
      eLife 2017; 6: Art. e27590
      Organizers play important roles during the embryonic development of many animals. The most famous example is the Spemann organizer that sets up embryonic axes in amphibian embryos. In spiders, a group of BMP secreting mesenchymal cells (the cumulus) functions as an organizer of the dorsoventral axis. Similar to experiments performed with the Spemann organizer, transplantation of the cumulus is able to induce a secondary axis in spiders. Despite the importance of this structure, it is unknown which factors are needed to activate cumulus specific gene expression. To address this question, we performed a transcriptomic analysis of early embryonic development in the spider Parasteatoda tepidariorum. Through this work, we found that the transcription factor Pt-Ets4 is needed for cumulus integrity, dorsoventral patterning and for the activation of Pt-hunchback and Pt-twist expression. Furthermore, ectopic expression of Pt-Ets4 is sufficient to induce cell delamination and migration by inducing a mesoderm-like cell fate.
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      Taxon- and Site-Specific Melatonin Catabolism 

      Hardeland, Rüdiger
      Molecules 2017; 22(11): Art. 2015
      Melatonin is catabolized both enzymatically and nonenzymatically. Nonenzymatic processes mediated by free radicals, singlet oxygen, other reactive intermediates such as HOCl and peroxynitrite, or pseudoenzymatic mechanisms are not species- or tissue-specific, but vary considerably in their extent. Higher rates of nonenzymatic melatonin metabolism can be expected upon UV exposure, e.g., in plants and in the human skin. Additionally, melatonin is more strongly nonenzymatically degraded at sites of inflammation. Typical products are several hydroxylated derivatives of melatonin and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK). Most of these products are also formed by enzymatic catalysis. Considerable taxon- and site-specific differences are observed in the main enzymatic routes of catabolism. Formation of 6-hydroxymelatonin by cytochrome P450 subforms are prevailing in vertebrates, predominantly in the liver, but also in the brain. In pineal gland and non-mammalian retina, deacetylation to 5-methoxytryptamine (5-MT) plays a certain role. This pathway is quantitatively prevalent in dinoflagellates, in which 5-MT induces cyst formation and is further converted to 5-methoxyindole-3-acetic acid, an end product released to the water. In plants, the major route is catalyzed by melatonin 2-hydroxylase, whose product is tautomerized to 3-acetamidoethyl-3-hydroxy-5-methoxyindolin-2-one (AMIO), which exceeds the levels of melatonin. Formation and properties of various secondary products are discussed.
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      Toward a monograph of non-marine Ulvophyceae using an integrative approach (Molecular phylogeny and systematics of terrestrial Ulvophyceae II.) 

      DARIENKO, TATYANA; PRÖSCHOLD, THOMAS
      Phytotaxa 2017; 324(1) p.001-041
      Phylogenetic analyses of SSU rDNA sequences have shown that coccoid and filamentous green algae are distributed among all classes of the Chlorophyta. One of these classes, the Ulvophyceae, mostly contains marine seaweeds and microalgae. However, new studies have shown that there are filamentous and sarcinoid freshwater and terrestrial species (including symbionts in lichens) among the Ulvophyceae, but very little is known about these species. Ultrastructural studies of some of them have confirmed that the flagellar apparatus of zoospores (counterclockwise basal body orientation) is typical for the Ulvophyceae. In addition to ultrastructural features, the presence of a “Codiolum”-stage is characteristic of some members of this algal class. We studied more than 50 strains of freshwater and terrestrial ulvophycean microalgae obtained from the different public culture collection and our own isolates using an integrative approach. Three independent lineages of the Ulvophyceae containing terrestrial species were revealed by these methods. Unexpectedly each of these lineages contained several isolates that morphologically developed a high degree of phenotypic plasticity, and included hidden phylogenetic diversity that let us to the description of several new genera and species.
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      A key role for foxQ2 in anterior head and central brain patterning in insects 

      Kitzmann, Peter; Weißkopf, Matthias; Schacht, Magdalena Ines; Bucher, Gregor
      Development 2017; 144(16) p.2969-2981
      Anterior patterning of animals is based on a set of highly conserved transcription factors but the interactions within the protostome anterior gene regulatory network (aGRN) remain enigmatic. Here, we identify the red flour beetle Tribolium castaneum ortholog of foxQ2 (Tc-foxQ2) as a novel upstream component of the aGRN. It is required for the development of the labrum and higher order brain structures, namely the central complex and the mushroom bodies. We reveal Tc-foxQ2 interactions by RNAi and heat shock-mediated misexpression. Surprisingly, Tc-foxQ2 and Tc-six3 mutually activate each other, forming a novel regulatory module at the top of the aGRN. Comparisons of our results with those of sea urchins and cnidarians suggest that foxQ2 has acquired more upstream functions in the aGRN during protostome evolution. Our findings expand the knowledge on foxQ2 gene function to include essential roles in epidermal development and central brain patterning.
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