Zuletzt publiziert

  • Zeitschriftenartikel

    Neural and Response Correlations to Complex Natural Sounds in the Auditory Midbrain. 

    Lyzwa, Dominika; Wörgötter, Florentin
    Frontiers in neural circuits 2016; 10: Art. 89
    How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This raises the question of how similar the neural representation of the communication sounds is across these gradients of neural preferences, and whether it also changes gradually. Analyzed neural recordings were multi-unit cluster spike trains from guinea pigs presented with a spectrotemporally rich set of eleven species-specific communication sounds. Using cross-correlation, we analyzed the response similarity of spiking activity across a broad frequency range for neurons of similar and different frequency tuning. Furthermore, we separated the contribution of the stimulus to the correlations to investigate whether similarity is only attributable to the stimulus, or, whether interactions exist between the multi-unit clusters that lead to neural correlations and whether these follow the same representation as the response correlations. We found that similarity of responses is dependent on the neurons' spatial distance for similarly and differently frequency-tuned neurons, and that similarity decreases gradually with spatial distance. Significant neural correlations exist, and contribute to the total response similarity. Our findings suggest that for multi-unit clusters in the mammalian inferior colliculus, the gradual response similarity with spatial distance to natural complex sounds is shaped by neural interactions and the gradual organization of neural preferences.
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    Key Components of Different Plant Defense Pathways Are Dispensable for Powdery Mildew Resistance of the Arabidopsis mlo2 mlo6 mlo12 Triple Mutant. 

    Kuhn, Hannah; Lorek, Justine; Kwaaitaal, Mark; Consonni, Chiara; Becker, Katia; Micali, Cristina; Ver Loren van Themaat, Emiel; Bednarek, Paweł; Raaymakers, Tom M.; Appiano, Michela; et al.
    Bai, YulingMeldau, DorotheaBaum, StephaniConrath, UweFeussner, IvoPanstruga, Ralph
    Frontiers in plant science 2017; 8: Art. 1006
    Loss of function mutations of particular plant MILDEW RESISTANCE LOCUS O (MLO) genes confer durable and broad-spectrum penetration resistance against powdery mildew fungi. Here, we combined genetic, transcriptomic and metabolomic analyses to explore the defense mechanisms in the fully resistant Arabidopsis thaliana mlo2 mlo6 mlo12 triple mutant. We found that this genotype unexpectedly overcomes the requirement for indolic antimicrobials and defense-related secretion, which are critical for incomplete resistance of mlo2 single mutants. Comparative microarray-based transcriptome analysis of mlo2 mlo6 mlo12 mutants and wild type plants upon Golovinomyces orontii inoculation revealed an increased and accelerated accumulation of many defense-related transcripts. Despite the biotrophic nature of the interaction, this included the non-canonical activation of a jasmonic acid/ethylene-dependent transcriptional program. In contrast to a non-adapted powdery mildew pathogen, the adapted powdery mildew fungus is able to defeat the accumulation of defense-relevant indolic metabolites in a MLO protein-dependent manner. We suggest that a broad and fast activation of immune responses in mlo2 mlo6 mlo12 plants can compensate for the lack of single or few defense pathways. In addition, our results point to a role of Arabidopsis MLO2, MLO6, and MLO12 in enabling defense suppression during invasion by adapted powdery mildew fungi.
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    A Neurocomputational Model of Goal-Directed Navigation in Insect-Inspired Artificial Agents. 

    Goldschmidt, Dennis; Manoonpong, Poramate; Dasgupta, Sakyasingha
    Frontiers in neurorobotics 2017; 11: Art. 20
    Despite their small size, insect brains are able to produce robust and efficient navigation in complex environments. Specifically in social insects, such as ants and bees, these navigational capabilities are guided by orientation directing vectors generated by a process called path integration. During this process, they integrate compass and odometric cues to estimate their current location as a vector, called the home vector for guiding them back home on a straight path. They further acquire and retrieve path integration-based vector memories globally to the nest or based on visual landmarks. Although existing computational models reproduced similar behaviors, a neurocomputational model of vector navigation including the acquisition of vector representations has not been described before. Here we present a model of neural mechanisms in a modular closed-loop control-enabling vector navigation in artificial agents. The model consists of a path integration mechanism, reward-modulated global learning, random search, and action selection. The path integration mechanism integrates compass and odometric cues to compute a vectorial representation of the agent's current location as neural activity patterns in circular arrays. A reward-modulated learning rule enables the acquisition of vector memories by associating the local food reward with the path integration state. A motor output is computed based on the combination of vector memories and random exploration. In simulation, we show that the neural mechanisms enable robust homing and localization, even in the presence of external sensory noise. The proposed learning rules lead to goal-directed navigation and route formation performed under realistic conditions. Consequently, we provide a novel approach for vector learning and navigation in a simulated, situated agent linking behavioral observations to their possible underlying neural substrates.
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    Differential Effects of HCN Channel Block on On and Off Pathways in the Retina as a Potential Cause for Medication-Induced Phosphene Perception. 

    Bemme, Sebastian; Weick, Michael; Gollisch, Tim
    Investigative ophthalmology & visual science 2017-09-01; 58(11) p.4754-4767
    Purpose: Phosphene perception is a characteristic side effect of heart rate-reducing medication that acts on hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels. It is hypothesized that these phosphenes are caused by blocking HCN channels in photoreceptors and neurons of the retina, yet the underlying changes in visual signal processing in the retina caused by the HCN channel block are still unknown. Methods: We examined the effects of pharmacologic HCN channel block on the encoding of visual signals in retinal ganglion cells by recording ganglion cell spiking activity from isolated mouse retinas mounted on multielectrode arrays. Spontaneous activity and responses to various visual stimuli were measured before, during, and after administration of 3 μM ivabradine. Results: Retinal ganglion cells generally showed slower response kinetics and reduced sensitivity to high temporal frequencies under ivabradine. Moreover, ivabradine differentially affected the sensitivity of On and Off ganglion cells. On cells showed reduced response gain, whereas Off cells experienced an increase in response threshold. In line with these differential effects, Off cells, in contrast to On cells, also showed reduced baseline activity during visual stimulation and reduced spontaneous activity. Furthermore, Off cells, but not On cells, showed increased burst-like spiking activity in the presence of ivabradine. Conclusions: Our data suggest that pharmacologic HCN channel block in the retina leads to a shift in the relative activity of the On and Off pathways of the retina. We hypothesize that this imbalance may underlie the medication-induced perception of phosphenes.
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    Antenatal care services and its implications for vital and health outcomes of children: evidence from 193 surveys in 69 low-income and middle-income countries. 

    Kuhnt, Jana; Vollmer, Sebastian
    BMJ open 2017; 7(11): Art. e017122
    OBJECTIVES: Antenatal care (ANC) is an essential part of primary healthcare and its provision has expanded worldwide. There is limited evidence of large-scale cross-country studies on the impact of ANC offered to pregnant women on child health outcomes. We investigate the association of ANC in low-income and middle-income countries with short- and long-term mortality and nutritional child outcomes. SETTING: We used nationally representative health and welfare data from 193 Demographic and Health Surveys conducted between 1990 and 2013 from 69 low-income and middle-income countries for women of reproductive age (15-49 years), their children and their respective household. PARTICIPANTS: The analytical sample consisted of 752 635 observations for neonatal mortality, 574 675 observations for infant mortality, 400 426 observations for low birth weight, 501 484 observations for stunting and 512 424 observations for underweight. MAIN OUTCOMES AND MEASURES: Outcome variables are neonatal and infant mortality, low birth weight, stunting and underweight. RESULTS: At least one ANC visit was associated with a 1.04% points reduced probability of neonatal mortality and a 1.07% points lower probability of infant mortality. Having at least four ANC visits and having at least once seen a skilled provider reduced the probability by an additional 0.56% and 0.42% points, respectively. At least one ANC visit is associated with a 3.82% points reduced probability of giving birth to a low birth weight baby and a 4.11 and 3.26% points reduced stunting and underweight probability. Having at least four ANC visits and at least once seen a skilled provider reduced the probability by an additional 2.83%, 1.41% and 1.90% points, respectively. CONCLUSIONS: The currently existing and accessed ANC services in low-income and middle-income countries are directly associated with improved birth outcomes and longer-term reductions of child mortality and malnourishment.
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    A new instrument for stable isotope measurements of C-13 and O-18 in CO2 - instrument performance and ecological application of the Delta Ray IRIS analyzer 

    Braden-Behrens, Jelka; Yan, Yuan; Knohl, Alexander
    Atmospheric Measurement Techniques 2017; 10(11) p.4537-4560
    We used the recently developed commercially available Delta Ray isotope ratio infrared spectrometer (IRIS) to continuously measure the CO2 concentration c and its isotopic composition δ13C and δ18O in a managed beech forest in central Germany. Our objectives are (a) to characterize the Delta Ray IRIS and evaluate its internal calibration procedure and (b) to quantify the seasonal variability of c, δ13C, δ18O and the isotopic composition of nighttime net ecosystem CO2 exchange (respiration) Reco13C and Reco18O derived from Keeling plot intercepts. The analyzer's minimal Allan deviation (as a measure of precision) was below 0.01 ppm for the CO2 concentration and below 0.03 ‰ for both δ values. The potential accuracy (defined as the 1σ deviation from the respective linear regression that was used for calibration) was approximately 0.45 ppm for c, 0.24 ‰ for 13C and 0.3 ‰ for 18O. For repeated measurements of a target gas in the field, the long-term standard deviation from the mean was 0.3 ppm for c and below 0.3 ‰ for both δ values. We used measurements of nine different inlet heights to evaluate the isotopic compositions of nighttime net ecosystem CO2 exchange Reco13C and Reco18O in a 3-month measurement campaign in a beech forest in autumn 2015. During this period, an early snow and frost event occurred, coinciding with a change in the observed characteristics of both Reco13C and Reco18O. Before the first snow, Reco13C correlated significantly (p  <  10−4) with time-lagged net radiation Rn, a driver of photosynthesis and photosynthetic discrimination against 13C. This correlation became insignificant (p  >  0.1) for the period after the first snow, indicating a decoupling of δ13C of respiration from recent assimilates. For 18O, we measured a decrease of 30 ‰ within 10 days in Reco18O after the snow event, potentially reflecting the influence of 18O depleted snow on soil moisture. This decrease was 10 times larger than the corresponding decrease in δ18O in ambient CO2 (below 3 ‰) and took 3 times longer to recover (3 weeks vs. 1 week). In summary, we conclude that (1) the new Delta Ray IRIS with its internal calibration procedure provides an opportunity to precisely and accurately measure c, δ13C and δ18O at field sites and (2) even short snow or frost events might have strong effects on the isotopic composition (in particular 18O) of CO2 exchange on an ecosystem scale.
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    Environmental enrichment accelerates ocular dominance plasticity in mouse visual cortex whereas transfer to standard cages resulted in a rapid loss of increased plasticity. 

    Kalogeraki, Evgenia; Pielecka-Fortuna, Justyna; Löwel, Siegrid
    PloS one 2017; 12(10): Art. e0186999
    In standard cage (SC) raised mice, experience-dependent ocular dominance (OD) plasticity in the primary visual cortex (V1) rapidly declines with age: in postnatal day 25-35 (critical period) mice, 4 days of monocular deprivation (MD) are sufficient to induce OD-shifts towards the open eye; thereafter, 7 days of MD are needed. Beyond postnatal day 110, even 14 days of MD failed to induce OD-plasticity in mouse V1. In contrast, mice raised in a so-called "enriched environment" (EE), exhibit lifelong OD-plasticity. EE-mice have more voluntary physical exercise (running wheels), and experience more social interactions (bigger housing groups) and more cognitive stimulation (regularly changed labyrinths or toys). Whether experience-dependent shifts of V1-activation happen faster in EE-mice and how long the plasticity promoting effect would persist after transferring EE-mice back to SCs has not yet been investigated. To this end, we used intrinsic signal optical imaging to visualize V1-activation i) before and after MD in EE-mice of different age groups (from 1-9 months), and ii) after transferring mice back to SCs after postnatal day 130. Already after 2 days of MD, and thus much faster than in SC-mice, EE-mice of all tested age groups displayed a significant OD-shift towards the open eye. Transfer of EE-mice to SCs immediately abolished OD-plasticity: already after 1 week of SC-housing and MD, OD-shifts could no longer be visualized. In an attempt to rescue abolished OD-plasticity of these mice, we either administered the anti-depressant fluoxetine (in drinking water) or supplied a running wheel in the SCs. OD-plasticity was only rescued for the running wheel- mice. Altogether our results show that raising mice in less deprived environments like large EE-cages strongly accelerates experience-dependent changes in V1-activation compared to the impoverished SC-raising. Furthermore, preventing voluntary physical exercise of EE-mice in adulthood immediately precludes OD-shifts in V1.
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    Expansion of oil palm and other cash crops causes an increase of the land surface temperature in the Jambi province in Indonesia 

    Sabajo, Clifton R.; le Maire, Guerric; June, Tania; Meijide, Ana; Roupsard, Olivier; Knohl, Alexander
    Biogeosciences 2017; 14(20) p.4619-4635
    Indonesia is currently one of the regions with the highest transformation rate of land surface worldwide related to the expansion of oil palm plantations and other cash crops replacing forests on large scales. Land cover changes, which modify land surface properties, have a direct effect on the land surface temperature (LST), a key driver for many ecological functions. Despite the large historic land transformation in Indonesia toward oil palm and other cash crops and governmental plans for future expansion, this is the first study so far to quantify the impacts of land transformation on the LST in Indonesia. We analyze LST from the thermal band of a Landsat image and produce a highresolution surface temperature map (30 m) for the lowlands of the Jambi province in Sumatra (Indonesia), a region which suffered large land transformation towards oil palm and other cash crops over the past decades. The comparison of LST, albedo, normalized differenced vegetation index (NDVI) and evapotranspiration (ET) between seven different land cover types (forest, urban areas, clear-cut land, young and mature oil palm plantations, acacia and rubber plantations) shows that forests have lower surface temperatures than the other land cover types, indicating a local warming effect after forest conversion. LST differences were up to 10.1 2.6 C (mean SD) between forest and clear-cut land. The differences in surface temperatures are explained by an evaporative cooling effect, which offsets the albedo warming effect. Our analysis of the LST trend of the past 16 years based on MODIS data shows that the average daytime surface temperature in the Jambi province increased by 1.05 C, which followed the trend of observed land cover changes and exceeded the effects of climate warming. This study provides evidence that the expansion of oil palm plantations and other cash crops leads to changes in biophysical variables, warming the land surface and thus enhancing the increase of the air temperature because of climate change.
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    Bayesian refinement of protein structures and ensembles against SAXS data using molecular dynamics. 

    Shevchuk, Roman; Hub, Jochen S.
    PLoS computational biology 2017-10; 13(10): Art. e1005800
    Small-angle X-ray scattering is an increasingly popular technique used to detect protein structures and ensembles in solution. However, the refinement of structures and ensembles against SAXS data is often ambiguous due to the low information content of SAXS data, unknown systematic errors, and unknown scattering contributions from the solvent. We offer a solution to such problems by combining Bayesian inference with all-atom molecular dynamics simulations and explicit-solvent SAXS calculations. The Bayesian formulation correctly weights the SAXS data versus prior physical knowledge, it quantifies the precision or ambiguity of fitted structures and ensembles, and it accounts for unknown systematic errors due to poor buffer matching. The method further provides a probabilistic criterion for identifying the number of states required to explain the SAXS data. The method is validated by refining ensembles of a periplasmic binding protein against calculated SAXS curves. Subsequently, we derive the solution ensembles of the eukaryotic chaperone heat shock protein 90 (Hsp90) against experimental SAXS data. We find that the SAXS data of the apo state of Hsp90 is compatible with a single wide-open conformation, whereas the SAXS data of Hsp90 bound to ATP or to an ATP-analogue strongly suggest heterogenous ensembles of a closed and a wide-open state.
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    INA complex liaises the F1Fo-ATP synthase membrane motor modules. 

    Naumenko, Nataliia; Morgenstern, Marcel; Rucktäschel, Robert; Warscheid, Bettina; Rehling, Peter
    Nature communications 2017-11-01; 8(1): Art. 1237
    The F1F0-ATP synthase translates a proton flux across the inner mitochondrial membrane into a mechanical rotation, driving anhydride bond formation in the catalytic portion. The complex's membrane-embedded motor forms a proteinaceous channel at the interface between Atp9 ring and Atp6. To prevent unrestricted proton flow dissipating the H(+)-gradient, channel formation is a critical and tightly controlled step during ATP synthase assembly. Here we show that the INA complex (INAC) acts at this decisive step promoting Atp9-ring association with Atp6. INAC binds to newly synthesized mitochondrial-encoded Atp6 and Atp8 in complex with maturation factors. INAC association is retained until the F1-portion is built on Atp6/8 and loss of INAC causes accumulation of the free F1. An independent complex is formed between INAC and the Atp9 ring. We conclude that INAC maintains assembly intermediates of the F1 F0-ATP synthase in a primed state for the terminal assembly step-motor module formation.
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  • Working Paper

    “Go hard or go home!” 

    Kiep, Peter
    Göttinger Centrum für Geschlechterforschung, 2017
    Der gegenwärtige Trend der Körpermodellierung hat in den letzten Jahren ebenso stetig Veränderungen erfahren wie das kommerzielle Fitnessstudio als ein anerkannter Ort der Artikulation moderner Körperlichkeit. Dies zeigt sich insbesondere an den gestiegenen Ansprüchen hinsichtlich gesellschaftlich akzeptierter Körperideale. Dabei bedingt das Sporttreiben im Fitnessstudio positive wie auch negative Erfahrungen, die an das Aussehen und die sportliche Leistung gebunden sind. Hiervon ausgehend nimmt die vorliegende Studie an der Schnittstelle von Sportwissenschaften und Geschlechterforschung die Frage in den Blick, welche Bedeutung diverse Körper(-formen) für die Anerkennung junger Männer innerhalb der Fitnessszene haben. Hierbei werden zum einen positive Anerkennungserfahrungen basierend auf der richtigen Selbstinszenierung sowie der sportlichen Leistung deutlich. Zum anderen werden Abhängigkeiten zwischen Hierarchien unter Männern, körperbezogenen Diskriminierungstendenzen und der selbstbestimmten Teilnahme am körpermodellierenden Sport sichtbar.
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  • Zeitschriftenartikel

    Compromised neuroplasticity in cigarette smokers under nicotine withdrawal is restituted by the nicotinic α4β2-receptor partial agonist varenicline 

    Batsikadze, G.; Paulus, W.; Hasan, A.; Grundey, J.; Kuo, M.-F.; Nitsche, M. A.
    Scientific Reports 2017; 7(1): Art. 1387
    Nicotine modulates neuroplasticity and improves cognitive functions in animals and humans. In the brain of smoking individuals, calcium-dependent plasticity induced by non-invasive brain stimulation methods such as transcranial direct current stimulation (tDCS) and paired associative stimulation (PAS) is impaired by nicotine withdrawal, but partially re-established after nicotine re-administration. In order to investigate the underlying mechanism further, we tested the impact of the α4β2-nicotinic receptor partial agonist varenicline on focal and non-focal plasticity in smokers during nicotine withdrawal, induced by PAS and tDCS, respectively. We administered low (0.3 mg) and high (1.0 mg) single doses of varenicline or placebo medication before stimulation over the left motor cortex of 20 healthy smokers under nicotine withdrawal. Motor cortex excitability was monitored by single-pulse transcranial magnetic stimulation-induced motor evoked potential amplitudes for 36 hours after plasticity induction. Stimulation-induced plasticity was absent under placebo medication, whereas it was present in all conditions under high dose. Low dose restituted only tDCS-induced non-focal plasticity, producing no significant impact on focal plasticity. High dose varenicline also prolonged inhibitory plasticity. These results are comparable to the impact of nicotine on withdrawal-related impaired plasticity in smokers and suggest that α4β2 nicotinic receptors are relevantly involved in plasticity deficits and restitution in smokers.
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    Regulation of Prp43-mediated disassembly of spliceosomes by its cofactors Ntr1 and Ntr2 

    Fourmann, Jean-Baptiste; Tauchert, Marcel J.; Ficner, Ralf; Fabrizio, Patrizia; Lührmann, Reinhard
    Nucleic Acids Research 2016; 45(7) p.4068-4080
    The DEAH-box NTPase Prp43 disassembles spliceosomes in co-operation with the cofactors Ntr1/Spp382 and Ntr2, forming the NTR complex. How Prp43 is regulated by its cofactors to discard selectively only intron-lariat spliceosomes (ILS) and defective spliceosomes and to prevent disassembly of earlier and properly assembled/wild-type spliceosomes remains unclear. First, we show that Ntr1΄s G-patch motif (Ntr1GP) can be replaced by the GP motif of Pfa1/Sqs1, a Prp43΄s cofactor in ribosome biogenesis, demonstrating that the specific function of Ntr1GP is to activate Prp43 for spliceosome disassembly and not to guide Prp43 to its binding site in the spliceosome. Furthermore, we show that Ntr1΄s C-terminal domain (CTD) plays a safeguarding role by preventing Prp43 from disrupting wild-type spliceosomes other than the ILS. Ntr1 and Ntr2 can also discriminate between wild-type and defective spliceosomes. In both type of spliceosomes, Ntr1-CTD impedes Prp43-mediated disassembly while the Ntr1GP promotes disassembly. Intriguingly, Ntr2 plays a specific role in defective spliceosomes, likely by stabilizing Ntr1 and allowing Prp43 to enter a productive interaction with the GP motif of Ntr1. Our data indicate that Ntr1 and Ntr2 act as ‘doorkeepers’ and suggest that both cofactors inspect the RNP structure of spliceosomal complexes thereby targeting suboptimal spliceosomes for Prp43-mediated disassembly.
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    BRD4 promotes p63 and GRHL3 expression downstream of FOXO in mammary epithelial cells 

    Nagarajan, Sankari; Bedi, Upasana; Budida, Anusha; Hamdan, Feda H.; Mishra, Vivek Kumar; Najafova, Zeynab; Xie, Wanhua; Alawi, Malik; Indenbirken, Daniela; Knapp, Stefan; et al.
    Chiang, Cheng-MingGrundhoff, AdamKari, VijayalakshmiScheel, Christina H.Wegwitz, FlorianJohnsen, Steven A.
    Nucleic Acids Research 2016; 45(6) p.3130-3145
    Bromodomain-containing protein 4 (BRD4) is a member of the bromo- and extraterminal (BET) domain-containing family of epigenetic readers which is under intensive investigation as a target for anti-tumor therapy. BRD4 plays a central role in promoting the expression of select subsets of genes including many driven by oncogenic transcription factors and signaling pathways. However, the role of BRD4 and the effects of BET inhibitors in non-transformed cells remain mostly unclear. We demonstrate that BRD4 is required for the maintenance of a basal epithelial phenotype by regulating the expression of epithelial-specific genes including TP63 and Grainy Head-like transcription factor-3 (GRHL3) in non-transformed basal-like mammary epithelial cells. Moreover, BRD4 occupancy correlates with enhancer activity and enhancer RNA (eRNA) transcription. Motif analyses of cell context-specific BRD4-enriched regions predicted the involvement of FOXO transcription factors. Consistently, activation of FOXO1 function via inhibition of EGFR-AKT signaling promoted the expression of TP63 and GRHL3. Moreover, activation of Src kinase signaling and FOXO1 inhibition decreased the expression of FOXO/BRD4 target genes. Together, our findings support a function for BRD4 in promoting basal mammary cell epithelial differentiation, at least in part, by regulating FOXO factor function on enhancers to activate TP63 and GRHL3 expression.
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    The house spider genome reveals an ancient whole-genome duplication during arachnid evolution 

    Schwager, Evelyn E.; Sharma, Prashant P.; Clarke, Thomas; Leite, Daniel J.; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; et al.
    Buffry, Alexandra D.Chao, HsuDinh, HuyenDoddapaneni, HarshaVardhanDugan, ShannonEibner, CorneliusExtavour, Cassandra G.Funch, PeterGarb, JessicaGonzalez, Luis B.Gonzalez, Vanessa L.Griffiths-Jones, SamHan, YiHayashi, CherylHilbrant, MaartenHughes, Daniel S. T.Janssen, RalfLee, Sandra L.Maeso, IgnacioMurali, Shwetha C.Muzny, Donna M.Nunes da Fonseca, RodrigoPaese, Christian L. B.Qu, JiaxinRonshaugen, MatthewSchomburg, ChristophSchönauer, AnnaStollewerk, AngelikaTorres-Oliva, MontserratTuretzek, NataschaVanthournout, BramWerren, John H.Wolff, CarstenWorley, Kim C.Bucher, GregorGibbs, Richard A.Coddington, JonathanOda, HirokiStanke, MarioAyoub, Nadia A.Prpic, Nikola-MichaelFlot, Jean-FrançoisPosnien, NicoRichards, StephenMcGregor, Alistair P.
    BMC Biology 2017; 15(62) p.1-27
    The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.
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    Rapid diversification of homothorax expression patterns after gene duplication in spiders 

    Turetzek, Natascha; Khadjeh, Sara; Schomburg, Christoph; Prpic, Nikola-Michael
    BMC Evolutionary Biology 2017; 17(1)
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    EndophilinAs regulate endosomal sorting of BDNF-TrkB to mediate survival signaling in hippocampal neurons 

    Burk, Katja; Murdoch, John D.; Freytag, Siona; Koenig, Melanie; Bharat, Vinita; Markworth, Ronja; Burkhardt, Susanne; Fischer, Andre; Dean, Camin
    Scientific Reports 2017; 7(1): Art. 2149
    The sorting of activated receptors into distinct endosomal compartments is essential to activate specific signaling cascades and cellular events including growth and survival. However, the proteins involved in this sorting are not well understood. We discovered a novel role of EndophilinAs in sorting of activated BDNF-TrkB receptors into late endosomal compartments. Mice lacking all three EndophilinAs accumulate Rab7-positive late endosomes. Moreover, EndophilinAs are differentially localized to, co-traffic with, and tubulate, distinct endosomal compartments: In response to BDNF, EndophilinA2 is recruited to both early and late endosomes, EndophilinA3 is recruited to Lamp1-positive late endosomes, and co-trafficks with Rab5 and Rab7 in both the presence and absence of BDNF, while EndophilinA1 colocalizes at lower levels with endosomes. The absence of all three EndophilinAs caused TrkB to accumulate in EEA1 and Rab7-positive endosomes, and impaired BDNF-TrkB-dependent survival signaling cascades. In addition, EndophilinA triple knockout neurons exhibited increased cell death which could not be rescued by exogenous BDNF, in a neurotrophin-dependent survival assay. Thus, EndophilinAs differentially regulate activated receptor sorting via distinct endosomal compartments to promote BDNF-dependent cell survival.
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  • Working Paper

    Zur symbolischen Kastration von traditionellen Männlichkeiten 

    Schwanke, Julia
    Göttinger Centrum für Geschlechterforschung: Göttingen, 2017
    Die österreichische Schriftstellerin Elfriede Jelinek (*1946) gilt als Autorin, die durch die überspitzte Darstellung der männlichen Herrschaft patriarchale Herrschaftsformen kritisiert. Der vorliegende Beitrag analysiert zwei Romane Jelineks der 1980er Jahre aus gendertheoretischer Sicht: Die Ausgesperr-ten und Die Klavierspielerin. Es wird gezeigt, dass Jelinek über eine einfache Patriarchatskritik hinaus-geht, indem sie die männliche Herrschaft ad absurdum führt – sie führt symbolisch kastrierte Männ-lichkeiten als Persiflage einer traditionellen Männlichkeit vor. Für die Analyse werden soziologische geschlechts- und klassentheoretische Ansätze mit einer Methode zur Figurenanalyse verbunden. Mi-chael Meusers Ansatz, welcher Raewyn Connells Konzept der hegemonialen Männlichkeit mit Pierre Bourdieus Habitus-Konzept verbindet, wird in die Figurenanalyse Jens Eders integriert. Dadurch wird die Performanz von Männlichkeit in Jelineks Prosa sichtbar(er) gemacht und in den Kontext ei-ner doppelten Distinktions- und Dominanzlogik eingeordnet. Im Zuge der Analyse wird deutlich, dass die männlichen Figuren, welche sich bei der Konstruktion ihrer Männlichkeit am Ideal der he-gemonialen Männlichkeit orientieren, zum Scheitern verurteilt sind. Sie können den Anforderungen, die das Patriarchat mit der Verkörperung einer hegemonialen Männlichkeit an sie stellt, nicht gerecht werden. Jelinek kastriert sie symbolisch.
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    Levels and trends of childhood undernutrition by wealth and education according to a Composite Index of Anthropometric Failure: evidence from 146 Demographic and Health Surveys from 39 countries 

    Vollmer, Sebastian; Harttgen, Kenneth; Kupka, Roland; Subramanian, S. V.
    BMJ Global Health 2017; 2(2): Art. e000206
    Background Governments have endorsed global targets to reduce childhood undernutrition as part of the Sustainable Development Goals. Understanding the socioeconomic differences in childhood undernutrition has the potential to be helpful for targeting policy to reach these goals. Methods We specify a logistic regression model with the Composite Index of Anthropometric Failure (CIAF) as the outcome and indicator variables for wealth quartiles, maternal education categories and a set of covariates as explanatory variables. Wealth and education variables are interacted with a period indicator for 1990–2000 compared with 2001–2014 to observe differences over time. Based on these regressions we calculate predicted CIAF prevalence by wealth and education categories and over time. Results The sample included 146 surveys from 39 low-income and lower-middle-income countries with an overall sample size of 533 217 children. CIAF prevalence was 47.5% in 1990–2000, and it declined to 42.6% in 2001–2014. In 1990–2000 the CIAF prevalence of children with mothers with less than primary education was 31 percentage points higher than for mothers with secondary or higher education. This difference slightly decreased to 27 percentage points in 2001–2014. The difference in predicted CIAF prevalence of children from the highest and lowest wealth quartiles was 21 percentage points and did not change over time. Conclusions We find evidence for persistent and even increasing socioeconomic inequalities in childhood undernutrition, which underlines the importance of previous calls for equity-driven approaches targeting the most vulnerable to reduce childhood malnutrition.
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    Breakdown of local information processing may underlie isoflurane anesthesia effects. 

    Wollstadt, Patricia; Sellers, Kristin K; Rudelt, Lucas; Priesemann, Viola; Hutt, Axel; Fröhlich, Flavio; Wibral, Michael
    PLoS computational biology 2017-06; 13(6): Art. e1005511
    The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source-such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)-as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy-suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling.
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