TY - JOUR A1 - Nagel, Rebecca A1 - Kirschbaum, Frank A1 - Engelmann, Jacob A1 - Hofmann, Volker A1 - Pawelzik, Felix A1 - Tiedemann, Ralph T1 - Male-mediated species recognition among African weakly electric fishes JF - Royal Society Open Science N2 - Effective communication among sympatric species is often instrumental for behavioural isolation, where the failure to successfully discriminate between potential mates could lead to less fit hybrid offspring. Discrimination between con- and heterospecifics tends to occur more often in the sex that invests more in offspring production, i.e. females, but males may also mediate reproductive isolation. In this study, we show that among two Campylomormyrus Africanweakly electric fish species, males preferentially associate with conspecific females during choice tests using live fish as stimuli, i.e. when all sensory modalities potentially used for communication were present. We then conducted playback experiments to determine whether the species-specific electric organ discharge (EOD) used for electrocommunication serves as the cue for this conspecific association preference. Interestingly, only C. compressirostris males associated significantly more with the conspecific EOD waveform when playback stimuli were provided, while no such association preference was observed in C. tamandua males. Given our results, the EOD appears to serve, in part, as a male-mediated pre-zygotic isolation mechanism among sympatric species. However, the failure of C. tamandua males to discriminate between con- and heterospecific playback discharges suggests that multiple modalities may be necessary for species recognition in some African weakly electric fish species. KW - Campylomormyrus KW - communication KW - electric fishes KW - pre-zygotic isolation KW - species recognition Y1 - 2018 U6 - https://doi.org/10.1098/rsos.170443 SN - 2054-5703 VL - 5 IS - 2 PB - Royal Society CY - London ER - TY - JOUR A1 - Marelja, Zvonimir A1 - Leimkühler, Silke A1 - Missirlis, Fanis T1 - Iron sulfur and molybdenum cofactor enzymes regulate the drosophila life cycle by controlling cell metabolism JF - Frontiers in physiology N2 - Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which may function as a mitochondrial iron sensor since it is inactivated by iron; (iii) with the Krebs cycle thus disrupted, citrate is exported to the cytosol for fatty acid synthesis, while succinyl-CoA and the iron are used for heme biosynthesis; (iv) as iron is used for heme biosynthesis its concentration in the matrix drops allowing for manganese to reactivate superoxide dismutase and Fe-S cluster biosynthesis to reestablish the Krebs cycle. KW - aldehyde oxidase KW - DNA polymerase KW - electron transport chain KW - ecdysone KW - iron regulatory protein KW - quiescent mitochondria KW - magnetoreceptor KW - mitoflashes Y1 - 2018 U6 - https://doi.org/10.3389/fphys.2018.00050 SN - 1664-042X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Nizardo, Noverra M. A1 - Schanzenbach, Dirk A1 - Schönemann, Eric A1 - Laschewsky, Andre T1 - Exploring poly(ethylene glycol)-polyzwitterion diblock copolymers as biocompatible smart macrosurfactants featuring UCST-phase behavior in normal saline solution JF - Polymers N2 - Nonionic-zwitterionic diblock copolymers are designed to feature a coil-to-globule collapse transition with an upper critical solution temperature (UCST) in aqueous media, including physiological saline solution. The block copolymers that combine presumably highly biocompatible blocks are synthesized by chain extension of a poly(ethylene glycol) (PEG) macroinitiator via atom transfer radical polymerization (ATRP) of sulfobetaine and sulfabetaine methacrylates. Their thermoresponsive behavior is studied by variable temperature turbidimetry and H-1 NMR spectroscopy. While the polymers with polysulfobetaine blocks exhibit phase transitions in the physiologically interesting window of 30-50 degrees C only in pure aqueous solution, the polymers bearing polysulfabetaine blocks enabled phase transitions only in physiological saline solution. By copolymerizing a pair of structurally closely related sulfo-and sulfabetaine monomers, thermoresponsive behavior can be implemented in aqueous solutions of both low and high salinity. Surprisingly, the presence of the PEG blocks can affect the UCST-transitions of the polyzwitterions notably. In specific cases, this results in "schizophrenic" thermoresponsive behavior displaying simultaneously an UCST and an LCST (lower critical solution temperature) transition. Exploratory experiments on the UCST-transition triggered the encapsulation and release of various solvatochromic fluorescent dyes as model "cargos" failed, apparently due to the poor affinity even of charged organic compounds to the collapsed state of the polyzwitterions. KW - block copolymer KW - amphiphile KW - macrosurfactant KW - thermoresponsive self-assembly KW - polyzwitterion KW - upper critical solution temperature (UCST) KW - salting-in Y1 - 2018 U6 - https://doi.org/10.3390/polym10030325 SN - 2073-4360 VL - 10 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Topçu, Çağdaş A1 - Frühwirth, Matthias A1 - Moser, Maximilian A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij T1 - Disentangling respiratory sinus arrhythmia in heart rate variability records JF - Physiological Measurement N2 - Objective: Several different measures of heart rate variability, and particularly of respiratory sinus arrhythmia, are widely used in research and clinical applications. For many purposes it is important to know which features of heart rate variability are directly related to respiration and which are caused by other aspects of cardiac dynamics. Approach: Inspired by ideas from the theory of coupled oscillators, we use simultaneous measurements of respiratory and cardiac activity to perform a nonlinear disentanglement of the heart rate variability into the respiratory-related component and the rest. Main results: The theoretical consideration is illustrated by the analysis of 25 data sets from healthy subjects. In all cases we show how the disentanglement is manifested in the different measures of heart rate variability. Significance: The suggested technique can be exploited as a universal preprocessing tool, both for the analysis of respiratory influence on the heart rate and in cases when effects of other factors on the heart rate variability are in focus. KW - respiratory sinus arrhythmia KW - heart rate variability KW - coupled oscillators model KW - phase dynamics KW - data analysis Y1 - 2018 U6 - https://doi.org/10.1088/1361-6579/aabea4 SN - 0967-3334 SN - 1361-6579 VL - 39 IS - 5 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Niebuur, Bart-Jan A1 - Puchmayr, Jonas A1 - Herold, Christian A1 - Kreuzer, Lucas A1 - Hildebrand, Viet A1 - Müller-Buschbaum, Peter A1 - Laschewsky, Andre A1 - Papadakis, Christine M. T1 - Polysulfobetaines in aqueous solution and in thin film geometry JF - Materials N2 - Polysulfobetaines in aqueous solution show upper critical solution temperature (UCST) behavior. We investigate here the representative of this class of materials, poly (N,N-dimethyl-N-(3-methacrylamidopropyl) ammonio propane sulfonate) (PSPP), with respect to: (i) the dynamics in aqueous solution above the cloud point as function of NaBr concentration; and (ii) the swelling behavior of thin films in water vapor as function of the initial film thickness. For PSPP solutions with a concentration of 5 wt.%, the temperature dependence of the intensity autocorrelation functions is measured with dynamic light scattering as function of molar mass and NaBr concentration (0-8 mM). We found a scaling of behavior for the scattered intensity and dynamic correlation length. The resulting spinodal temperatures showed a maximum at a certain (small) NaBr concentration, which is similar to the behavior of the cloud points measured previously by turbidimetry. The critical exponent of susceptibility depends on NaBr concentration, with a minimum value where the spinodal temperature is maximum and a trend towards the mean-field value of unity with increasing NaBr concentration. In contrast, the critical exponent of the correlation length does not depend on NaBr concentration and is lower than the value of 0.5 predicted by mean-field theory. For PSPP thin films, the swelling behavior was found to depend on film thickness. A film thickness of about 100 nm turns out to be the optimum thickness needed to obtain fast hydration with H2O. KW - polyzwitterions KW - polysulfobetaines KW - dynamic light scattering KW - phase behavior Y1 - 2018 U6 - https://doi.org/10.3390/ma11050850 SN - 1996-1944 VL - 11 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ijiri, Akira A1 - Inagaki, Fumio A1 - Kubo, Yusuke A1 - Adhikari, Rishi Ram A1 - Hattori, Shohei A1 - Hoshino, Tatsuhiko A1 - Imachi, Hiroyuki A1 - Kawagucci, Shinsuke A1 - Morono, Yuki A1 - Ohtomo, Yoko A1 - Ono, Shuhei A1 - Sakai, Sanae A1 - Takai, Ken A1 - Toki, Tomohiro A1 - Wang, David T. A1 - Yoshinaga, Marcos Y. A1 - Arnold, Gail L. A1 - Ashi, Juichiro A1 - Case, David H. A1 - Feseker, Tomas A1 - Hinrichs, Kai-Uwe A1 - Ikegawa, Yojiro A1 - Ikehara, Minoru A1 - Kallmeyer, Jens A1 - Kumagai, Hidenori A1 - Lever, Mark Alexander A1 - Morita, Sumito A1 - Nakamura, Ko-ichi A1 - Nakamura, Yuki A1 - Nishizawa, Manabu A1 - Orphan, Victoria J. A1 - Roy, Hans A1 - Schmidt, Frauke A1 - Tani, Atsushi A1 - Tanikawa, Wataru A1 - Terada, Takeshi A1 - Tomaru, Hitoshi A1 - Tsuji, Takeshi A1 - Tsunogai, Urumu A1 - Yamaguchi, Yasuhiko T. A1 - Yoshida, Naohiro T1 - Deep-biosphere methane production stimulated by geofluids in the Nankai accretionary complex JF - Science Advances Y1 - 2018 U6 - https://doi.org/10.1126/sciadv.aao4631 SN - 2375-2548 VL - 4 IS - 6 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Fabian, Jenny A1 - Zlatanovic, Sanja A1 - Mutz, Michael A1 - Grossart, Hans-Peter A1 - van Geldern, Robert A1 - Ulrich, Andreas A1 - Gleixner, Gerd A1 - Premke, Katrin T1 - Environmental control on microbial turnover of leaf carbon in streams BT - Ecological function of phototrophic-heterotrophic interactions JF - Frontiers in microbiology N2 - In aquatic ecosystems, light availability can significantly influence microbial turnover of terrestrial organic matter through associated metabolic interactions between phototrophic and heterotrophic communities. However, particularly in streams, microbial functions vary significantly with the structure of the streambed, that is the distribution and spatial arrangement of sediment grains in the streambed. It is therefore essential to elucidate how environmental factors synergistically define the microbial turnover of terrestrial organic matter in order to better understand the ecological role of photoheterotrophic interactions in stream ecosystem processes. In outdoor experimental streams, we examined how the structure of streambeds modifies the influence of light availability on microbial turnover of leaf carbon (C). Furthermore, we investigated whether the studied relationships of microbial leaf C turnover to environmental conditions are affected by flow intermittency commonly occurring in streams. We applied leaves enriched with a C-13-stable isotope tracer and combined quantitative and isotope analyses. We thereby elucidated whether treatment induced changes in C turnover were associated with altered use of leaf C within the microbial food web. Moreover, isotope analyses were combined with measurements of microbial community composition to determine whether changes in community function were associated with a change in community composition. In this study, we present evidence, that environmental factors interactively determine how phototrophs and heterotrophs contribute to leaf C turnover. Light availability promoted the utilization of leaf C within the microbial food web, which was likely associated with a promoted availability of highly bioavailable metabolites of phototrophic origin. However, our results additionally confirm that the structure of the streambed modifies light-related changes in microbial C turnover. From our observations, we conclude that the streambed structure influences the strength of photo-heterotrophic interactions by defining the spatial availability of algal metabolites in the streambed and the composition of microbial communities. Collectively, our multifactorial approach provides valuable insights into environmental controls on the functioning of stream ecosystems. KW - algae KW - bacteria KW - microbial interactions KW - C-13 stable isotopes KW - PLFA KW - terrestrial carbon KW - streambed structure KW - light Y1 - 2018 U6 - https://doi.org/10.3389/fmicb.2018.01044 SN - 1664-302X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Stoessel, Daniel A1 - Stellmann, Jan-Patrick A1 - Willing, Anne A1 - Behrens, Birte A1 - Rosenkranz, Sina C. A1 - Hodecker, Sibylle C. A1 - Stuerner, Klarissa H. A1 - Reinhardt, Stefanie A1 - Fleischer, Sabine A1 - Deuschle, Christian A1 - Maetzler, Walter A1 - Berg, Daniela A1 - Heesen, Christoph A1 - Walther, Dirk A1 - Schauer, Nicolas A1 - Friese, Manuel A. A1 - Pless, Ole T1 - Metabolomic Profiles for Primary Progressive Multiple Sclerosis Stratification and Disease Course Monitoring JF - Frontiers in human neuroscienc N2 - Primary progressive multiple sclerosis (PPMS) shows a highly variable disease progression with poor prognosis and a characteristic accumulation of disabilities in patients. These hallmarks of PPMS make it difficult to diagnose and currently impossible to efficiently treat. This study aimed to identify plasma metabolite profiles that allow diagnosis of PPMS and its differentiation from the relapsing remitting subtype (RRMS), primary neurodegenerative disease (Parkinson’s disease, PD), and healthy controls (HCs) and that significantly change during the disease course and could serve as surrogate markers of multiple sclerosis (MS)-associated neurodegeneration over time. We applied untargeted high-resolution metabolomics to plasma samples to identify PPMS-specific signatures, validated our findings in independent sex- and age-matched PPMS and HC cohorts and built discriminatory models by partial least square discriminant analysis (PLS-DA). This signature was compared to sex- and age-matched RRMS patients, to patients with PD and HC. Finally, we investigated these metabolites in a longitudinal cohort of PPMS patients over a 24-month period. PLS-DA yielded predictive models for classification along with a set of 20 PPMS-specific informative metabolite markers. These metabolites suggest disease-specific alterations in glycerophospholipid and linoleic acid pathways. Notably, the glycerophospholipid LysoPC(20:0) significantly decreased during the observation period. These findings show potential for diagnosis and disease course monitoring, and might serve as biomarkers to assess treatment efficacy in future clinical trials for neuroprotective MS therapies. KW - untargeted metabolomics KW - biomarker KW - PPMS KW - MS neurodegeneration KW - LysoPC(20:0) Y1 - 2018 U6 - https://doi.org/10.3389/fnhum.2018.00226 SN - 1662-5161 VL - 12 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Merks, Anne Margarete A1 - Swinarski, Marie A1 - Meyer, Alexander Matthias A1 - Müller, Nicola Victoria A1 - Özcan, Ismail A1 - Donat, Stefan A1 - Burger, Alexa A1 - Gilbert, Stephen A1 - Mosimann, Christian A1 - Abdelilah-Seyfried, Salim A1 - Panakova, Daniela T1 - Planar cell polarity signalling coordinates heart tube remodelling through tissue-scale polarisation of actomyosin activity JF - Nature Communications N2 - Development of a multiple-chambered heart from the linear heart tube is inherently linked to cardiac looping. Although many molecular factors regulating the process of cardiac chamber ballooning have been identified, the cellular mechanisms underlying the chamber formation remain unclear. Here, we demonstrate that cardiac chambers remodel by cell neighbour exchange of cardiomyocytes guided by the planar cell polarity (PCP) pathway triggered by two non-canonical Wnt ligands, Wnt5b and Wnt11. We find that PCP signalling coordinates the localisation of actomyosin activity, and thus the efficiency of cell neighbour exchange. On a tissue-scale, PCP signalling planar-polarises tissue tension by restricting the actomyosin contractility to the apical membranes of outflow tract cells. The tissue-scale polarisation of actomyosin contractility is required for cardiac looping that occurs concurrently with chamber ballooning. Taken together, our data reveal that instructive PCP signals couple cardiac chamber expansion with cardiac looping through the organ-scale polarisation of actomyosin-based tissue tension. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-018-04566-1 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Schlegl, Sandra A1 - Dittmer, Nina A1 - Hoffmann, Svenja A1 - Voderholzer, Ulrich T1 - Self-reported quantity, compulsiveness and motives of exercise in patients with eating disorders and healthy controls BT - differences and similarities JF - Journal of eating disorders N2 - Background: Compulsive exercise (CE) is a frequent symptom in patients with eating disorders (EDs). It includes, in addition to quantitatively excessive exercise behaviour, a driven aspect and specific motives of exercise. CE is generally associated with worse therapy outcomes. The aims of the study were to compare self-reported quantity of exercise, compulsiveness of exercise as well as motives for exercise between patients with anorexia nervosa (AN), bulimia nervosa (BN) and healthy controls (HC). Additionally, we wanted to explore predictors of compulsive exercise (CE) in each group. Methods: We investigated 335 female participants (n = 226 inpatients, n = 109 HC) and assessed self-reported quantity of exercise, compulsiveness of exercise (Compulsive Exercise Test), motives for exercise (Exercise Motivations Inventory-2), ED symptoms (Eating Disorder Inventory-2), obsessive-compulsiveness (Obsessive-Compulsive Inventory-Revised), general psychopathology (Brief Symptom Inventory-18) and depression (Beck Depression Inventory-2). Results: Both patients with AN and BN exercised significantly more hours per week and showed significantly higher CE than HC; no differences were found between patients with AN and BN. Patients with EDs and HC also partly varied in motives for exercise. Specific motives were enjoyment, challenge, recognition and weight management in patients with EDs in contrast to ill-health avoidance and affiliation in HC. Patients with AN and BN only differed in regard to exercise for appearance reasons in which patients with BN scored higher. The most relevant predictor of CE across groups was exercise for weight and shape reasons. Conclusions: Exercise behaviours and motives differ between patients with EDs and HC. CE was pronounced in both patients with AN and BN. Therefore, future research should focus not only on CE in patients with AN, but also on CE in patients with BN. Similarities in CE in patients with AN and BN support a transdiagnostic approach during the development of interventions specifically targeting CE in patients with EDs. KW - Anorexia nervosa KW - Bulimia nervosa KW - Eating disorders KW - Compulsive exercise KW - Motives for exercise KW - Inpatient KW - Predictor KW - Healthy controls Y1 - 2018 U6 - https://doi.org/10.1186/s40337-018-0202-6 SN - 2050-2974 VL - 6 PB - BMC CY - London ER -