TY - JOUR A1 - Rocchetti, Alessandra A1 - Sharma, Tripti A1 - Wulfetange, Camilla A1 - Scholz-Starke, Joachim A1 - Grippa, Alexandra A1 - Carpaneto, Armando A1 - Dreyer, Ingo A1 - Vitale, Alessandro A1 - Czempinski, Katrin A1 - Pedrazzini, Emanuela T1 - The putative K+ channel subunit AtKCO3 forms stable dimers in arabidopsis JF - Frontiers in plant science N2 - The permeation pore of K+ channels is formed by four copies of the pore domain. AtKCO3 is the only putative voltage-independent K+ channel subunit of Arabidopsis thaliana with a single pore domain. KCO3-like proteins recently emerged in evolution and, to date, have been found only in the genus Arabidopsis (A. thaliana and A. lyrata). We show that the absence of KCO3 does not cause marked changes in growth under various conditions. Only under osmotic stress we observed reduced root growth of the kco3-1 null-allele line. This phenotype was complemented by expressing a KCO3 mutant with an inactive pore, indicating that the function of KCO3 under osmotic stress does not depend on its direct ability to transport ions. Constitutively overexpressed AtKCO3 or AtKCO3::G FP are efficiently sorted to the tonoplast indicating that the protein is approved by the endoplasmic reticulum quality control. However, vacuoles isolated from transgenic plants do not have significant alterations in current density. Consistently, both AtKCO3 and AtKCO3::GFP are detected as homodimers upon velocity gradient centrifugation, an assembly state that would not allow for activity. We conclude that if AtKCO3 ever functions as a K+ channel, active tetramers are held by particularly weak interactions, are formed only in unknown specific conditions and may require partner proteins. KW - Arabidopsis KW - membrane proteins KW - potassium channels KW - protein assembly KW - tonoplast Y1 - 2012 U6 - https://doi.org/10.3389/fpls.2012.00251 SN - 1664-462X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Lucia Gomez-Porras, Judith A1 - Mauricio Riano-Pachon, Diego A1 - Benito, Begona A1 - Haro, Rosario A1 - Sklodowski, Kamil A1 - Rodriguez-Navarro, Alonso A1 - Dreyer, Ingo T1 - Phylogenetic analysis of K+ transporters in bryophytes, lycophytes, and flowering plants indicates a specialization of vascular plants JF - Frontiers in plant science N2 - As heritage from early evolution, potassium (K+) is absolutely necessary for all living cells. It plays significant roles as stabilizer in metabolism and is important for enzyme activation, stabilization of protein synthesis, and neutralization of negative charges on cellular molecules as proteins and nucleic acids. Land plants even enlarged this spectrum of K+ utilization after having gone ashore, despite the fact that K+ is far less available in their new oligotrophic habitats than in sea water. Inevitably, plant cells had to improve and to develop unique transport systems for K+ accumulation and distribution. In the past two decades a manifold of K+ transporters from flowering plants has been identified at the molecular level. The recently published genome of the fern ally Selaginella moellendorffii now helps in providing a better understanding on the molecular changes involved in the colonization of land and the development of the vasculature and the seeds. In this article we present an inventory of K+ transporters of this lycophyte and pigeonhole them together with their relatives from the moss Physcomitrella patens, the monocotyledon Oryza sativa, and two dicotyledonous species, the herbaceous plant Arabidopsis thaliana, and the tree Populus trichocarpa. Interestingly, the transition of green plants from an aqueous to a dry environment coincides with a dramatic reduction in the diversity of voltage-gated potassium channels followed by a diversification on the basis of one surviving K+ channel class. The first appearance of K+ release (K-out) channels in S. moellendorffii that were shown in Arabidopsis to be involved in xylem loading and guard cell closure coincides with the specialization of vascular plants and may indicate an important adaptive step. KW - potassium KW - transport KW - channel KW - voltage-dependent KW - voltage-independent KW - high-affinity KW - Selaginella Y1 - 2012 U6 - https://doi.org/10.3389/fpls.2012.00167 SN - 1664-462X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Christian, Jan-Ole A1 - Braginets, Rostyslav A1 - Schulze, Waltraud X. A1 - Walther, Dirk T1 - Characterization and prediction of protein phosphorylation hotspots in Arabidopsis thaliana JF - Frontiers in plant science N2 - The regulation of protein function by modulating the surface charge status via sequence-locally enriched phosphorylation sites (P-sites) in so called phosphorylation "hotspots" has gained increased attention in recent years. We set out to identify P-hotspots in the model plant Arabidopsis thaliana. We analyzed the spacing of experimentally detected P-sites within peptide-covered regions along Arabidopsis protein sequences as available from the PhosPhAt database. Confirming earlier reports (Schweiger and Lanial, 2010), we found that, indeed, P-sites tend to cluster and that distributions between serine and threonine P-sites to their respected closest next P-site differ significantly from those for tyrosine P-sites. The ability to predict P-hotspots by applying available computational P-site prediction programs that focus on identifying single P-sites was observed to be severely compromised by the inevitable interference of nearby P-sites. We devised a new approach, named HotSPotter, for the prediction of phosphorylation hotspots. HotSPotter is based primarily on local amino acid compositional preferences rather than sequence position-specific motifs and uses support vector machines as the underlying classification engine. HotSPotter correctly identified experimentally determined phosphorylation hotspots in A. thaliana with high accuracy. Applied to the Arabidopsis proteome, HotSPotter-predicted 13,677 candidate P-hotspots in 9,599 proteins corresponding to 7,847 unique genes. Hotspot containing proteins are involved predominantly in signaling processes confirming the surmised modulating role of hotspots in signaling and interaction events. Our study provides new bioinformatics means to identify phosphorylation hotspots and lays the basis for further investigating novel candidate P-hotspots. All phosphorylation hotspot annotations and predictions have been made available as part of the PhosPhAt database at http://phosphat.mpimp-golm.mpg.de. KW - protein phosphorylation KW - hotspots KW - Arabidopsis thaliana KW - support vector machines KW - regulation Y1 - 2012 U6 - https://doi.org/10.3389/fpls.2012.00207 SN - 1664-462X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Balazadeh, Salma A1 - Jaspert, Nils A1 - Arif, Muhammad A1 - Müller-Röber, Bernd A1 - Maurino, Veronica G. T1 - Expression of ROS-responsive genes and transcription factors after metabolic formation of H2O2 in chloroplasts JF - Frontiers in plant science N2 - Glycolate oxidase (GO) catalyses the oxidation of glycolate to glyoxylate, thereby consuming O-2 and producing H2O2. In this work, Arabidopsis thaliana plants expressing GO in the chloroplasts (GO plants) were used to assess the expressional behavior of reactive oxygen species (ROS)-responsive genes and transcription factors (TFs) after metabolic induction of H2O2 formation in chloroplasts. In this organelle, GO uses the glycolate derived from the oxygenase activity of RubisCO. Here, to identify genes responding to an abrupt production of H2O2 in chloroplasts we used quantitative real-time PCR (qRT-PCR) to test the expression of 187 ROS-responsive genes and 1880 TFs after transferring GO and wild-type (WT) plants grown at high CO2 levels to ambient CO2 concentration. Our data revealed coordinated expression changes of genes of specific functional networks 0.5 h after metabolic induction of H2O2 production in GO plants, including the induction of indole glucosinolate and camalexin biosynthesis genes. Comparative analysis using available microarray data suggests that signals for the induction of these genes through H2O2 may originate in the chloroplast. The TF profiling indicated an up-regulation in GO plants of a group of genes involved in the regulation of proanthocyanidin and anthocyanin biosynthesis. Moreover, the upregulation of expression of IF and IF interacting proteins affecting development (e.g., cell division, stem branching, flowering time, flower development) would impact growth and reproductive capacity, resulting in altered development under conditions that promote the formation of H2O2. KW - glycolate oxidase KW - H2O2 KW - ROS-responsive genes KW - transcription factors Y1 - 2012 U6 - https://doi.org/10.3389/fpls.2012.00234 SN - 1664-462X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Spijkerman, Elly A1 - Wacker, Alexander A1 - Weithoff, Guntram A1 - Leya, Thomas T1 - Elemental and fatty acid composition of snow algae in Arctic habitats JF - Frontiers in microbiology N2 - Red, orange or green snow is the macroscopic phenomenon comprising different eukaryotic algae. Little is known about the ecology and nutrient regimes in these algal communities. Therefore, eight snow algal communities from five intensively tinted snow fields in western Spitsbergen were analysed for nutrient concentrations and fatty acid (FA) composition. To evaluate the importance of a shift from green to red forms on the FA-variability of the field samples, four snow algal strains were grown under nitrogen replete and moderate light (+N+ML) or N-limited and high light (-N+HL) conditions. All eight field algal communities were dominated by red and orange cysts. Dissolved nutrient concentration of the snow revealed a broad range of NH4+ (<0.005-1.2 mg NI-1) and only low PO43- (< 18 mu g P I-1) levels. The external nutrient concentration did not reflect cellular nutrient ratios as C:N and C:P ratios of the communities were highest at locations containing relatively high concentrations of NH4- and PO43-. Molar N:P ratios ranged from 11 to 21 and did not suggest clear limitation of a single nutrient. On a per carbon basis, we found a 6-fold difference in total FA content between the eight snow algal communities, ranging from 50 to 300 mg FA g C-1. In multivariate analyses total FA content opposed the cellular N:C quota and a large part of the FA variability among field locations originated from the abundant FAs C181n-9, C18 2n-6, and C183n-3. Both field samples and snow algal strains grown under -N+HL conditions had high concentrations of C181n-9. FAs possibly accumulated due to the cessation of growth. Differences in color and nutritional composition between patches of snow algal communities within one snow field were not directly related to nutrient conditions. We propose that the highly patchy distribution of snow algae within and between snow fields may also result from differences in topographical and geological parameters such as slope, melting water rivulets, and rock formation. KW - Arctic snow algal bloom KW - cellular C:N:P ratio KW - ecology KW - extremophiles KW - lipids KW - nutrients KW - psychrophilic. KW - Spitsbergen Y1 - 2012 U6 - https://doi.org/10.3389/fmicb.2012.00380 SN - 1664-302X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Kaplan, Aaron A1 - Harel, Moshe A1 - Kaplan-Levy, Ruth N. A1 - Hadas, Ora A1 - Sukenik, Assaf A1 - Dittmann-Thünemann, Elke T1 - The languages spoken in the water body (or the biological role of cyanobacterial toxins) JF - Frontiers in microbiology N2 - Although intensification of toxic cyanobacterial blooms over the last decade is a matter of growing concern due to bloom impact on water quality, the biological role of most of the toxins produced is not known. In this critical review we focus primarily on the biological role of two toxins, microcystins and cylindrospermopsin, in inter- and intra-species communication and in nutrient acquisition. We examine the experimental evidence supporting some of the dogmas in the field and raise several open questions to be dealt with in future research. We do not discuss the health and environmental implications of toxin presence in the water body. KW - aoa KW - cylindrospermopsin KW - microcystin KW - cyr KW - mcy Y1 - 2012 U6 - https://doi.org/10.3389/fmicb.2012.00138 SN - 1664-302X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Bickel, Samantha L. A1 - Tang, Kam W. A1 - Grossart, Hans-Peter T1 - Ciliate epibionts associated with crustacean zooplankton in German lakes - distribution, motility, and bacterivory JF - Frontiers in microbiology N2 - Ciliate epibionts associated with crustacean zooplankton are widespread in aquatic systems, but their ecological roles are little known. We studied the occurrence of ciliate epibionts on crustacean zooplankton in nine German lakes with different limnological features during the summer of 2011. We also measured the detachment and re-attachment rates of the ciliates, changes in their motility, and the feeding rates of attached vs. detached ciliate epibionts. Epibionts were found in all lakes sampled except an acidic lake with large humic inputs. Epibiont prevalence was as high as 80.96% on the cladoceran Daphnia cucullata, 67.17% on the cladoceran Diaphanosoma brachyurum, and 46.67% on the calanoid copepod Eudiaptomus gracilis. Both cladoceran groups typically had less than 10 epibionts per individual, while the epibiont load on E. gracilis ranged from 1 to >30 epibionts per individual. After the death of the zooplankton host, the peritrich ciliate epibiont Epistylis sp. detached in an exponential fashion with a half-life of 5 min, and 98% detached within 30 min, leaving behind the stalks used for attachment. Immediately after detachment, the ciliates were immotile, but 62% became motile within 60 min. When a new host was present, only 27% reattached after 120 min. The average measured ingestion rate and clearance rate of Epistylis were 11,745 bacteria ciliate(-1) h(-1) and 24.33 mu l ciliate(-1) h(-1), respectively. Despite their high feeding rates, relatively low epibiont abundances were observed in the field, which suggests either diversion of energy to stalk formation, high metabolic loss by the epibionts, or high mortality among the epibiont populations. KW - ciliate epibionts KW - Epistylis KW - crustacean zooplankton KW - bacterivory KW - epibiont motility Y1 - 2012 U6 - https://doi.org/10.3389/fmicb.2012.00243 SN - 1664-302X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Lauterbach, Daniel A1 - Ristow, Michael A1 - Gemeinholzer, Birgit T1 - Population genetics and fitness in fragmented populations of the dioecious and endangered Silene otites (Caryophyllaceae) JF - Plant systematics and evolution N2 - Population fragmentation is often correlated with loss of genetic diversity and reduced fitness. Obligate out-crossing (dioecy) is expected to enhance genetic diversity, reduce genetic differentiation, and avoid inbreeding depression through frequent gene flow. However, in highly fragmented populations dioecy has only diminishing effects upon genetic structure as pollination limitations (e.g. flight distance of pollinators) most often restrict inter-population gene flow in insect pollinated species. In fragmented dry grasslands in northeastern Germany, we analysed genetic structure, fitness, and habitat quality of the endangered dioecious Silene otites (Caryophyllaceae). Using AFLP markers, a high level of differentiation among ten populations was found (F (st) = 0.36), while the intra-population genetic diversities (H (E) = 0.165-0.240) were similar as compared to hermaphroditic species. There was neither a correlation between geographic and genetic distance nor between genetic diversity and population size, which indicates reduced gene flow among populations and random genetic drift. Plant size was positively correlated with genetic diversity. Seed set and number of juveniles were positively related to population size. Higher total coverage resulted in reduced plant fitness, and the number of juveniles was negatively correlated to cryptogam cover. Additionally, we found a sex ratio bias towards more male plants in larger populations. Overall, our results indicate that on a regional geographic scale dioecy does not necessarily prevent genetic erosion in the case of habitat fragmentation, especially in the absence of long distance seed and pollen dispersal capacity. KW - AFLP KW - Population size KW - Mating system KW - Isolation by distance KW - Sex ratio Y1 - 2012 U6 - https://doi.org/10.1007/s00606-011-0533-0 SN - 0378-2697 VL - 298 IS - 1 SP - 155 EP - 164 PB - Springer CY - Wien ER - TY - JOUR A1 - Araujo, Wagner L. A1 - Nunes-Nesi, Adriano A1 - Nikoloski, Zoran A1 - Sweetlove, Lee J. A1 - Fernie, Alisdair R. T1 - Metabolic control and regulation of the tricarboxylic acid cycle in photosynthetic and heterotrophic plant tissues JF - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology N2 - The tricarboxylic acid (TCA) cycle is a crucial component of respiratory metabolism in both photosynthetic and heterotrophic plant organs. All of the major genes of the tomato TCA cycle have been cloned recently, allowing the generation of a suite of transgenic plants in which the majority of the enzymes in the pathway are progressively decreased. Investigations of these plants have provided an almost complete view of the distribution of control in this important pathway. Our studies suggest that citrate synthase, aconitase, isocitrate dehydrogenase, succinyl CoA ligase, succinate dehydrogenase, fumarase and malate dehydrogenase have control coefficients flux for respiration of -0.4, 0.964, -0.123, 0.0008, 0.289, 0.601 and 1.76, respectively; while 2-oxoglutarate dehydrogenase is estimated to have a control coefficient of 0.786 in potato tubers. These results thus indicate that the control of this pathway is distributed among malate dehydrogenase, aconitase, fumarase, succinate dehydrogenase and 2-oxoglutarate dehydrogenase. The unusual distribution of control estimated here is consistent with specific non-cyclic flux mode and cytosolic bypasses that operate in illuminated leaves. These observations are discussed in the context of known regulatory properties of the enzymes and some illustrative examples of how the pathway responds to environmental change are given. KW - metabolic control analysis KW - metabolic regulation KW - respiration KW - Solanum lycopersicum (tomato) KW - TCA cycle Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-3040.2011.02332.x SN - 0140-7791 VL - 35 IS - 1 SP - 1 EP - 21 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Stojanovic, Milovan A1 - Markovic, Rade A1 - Kleinpeter, Erich A1 - Baranac-Stojanovic, Marija T1 - Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions JF - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry N2 - Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed. Instead, the bicyclic (5,6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic control, whereas the formation of the eight-membered ring was kinetically controlled. Y1 - 2012 U6 - https://doi.org/10.1039/c1ob06451g SN - 1477-0520 VL - 10 IS - 3 SP - 575 EP - 589 PB - Royal Society of Chemistry CY - Cambridge ER - TY - INPR A1 - Baret, Jean-Christophe A1 - Belder, Detlev A1 - Bier, Frank Fabian A1 - Cao, Jialan A1 - Gruschke, Oliver A1 - Hardt, Steffen A1 - Kirschbaum, Michael A1 - Koehler, J. Michael A1 - Schumacher, Soeren A1 - Urban, G. A. A1 - Viefhues, Martina T1 - Contributors to the 10th Anniversary Germany issue T2 - LAB on a chip : miniaturisation for chemistry and biology Y1 - 2012 U6 - https://doi.org/10.1039/c1lc90139g SN - 1473-0197 VL - 12 IS - 3 SP - 419 EP - 421 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Lauterbach, Daniel A1 - Burkart, Michael A1 - Gemeinholzer, Birgit T1 - Rapid genetic differentiation between ex situ and their in situ source populations - an example of the endangered Silene otites (Caryophyllaceae) JF - Botanical journal of the Linnean Society N2 - Ex situ cultivation in botanic gardens could be one possibility to preserve plant species diversity and genetic variation. However, old ex situ populations are often sparsely documented. We were able to retrieve three different ex situ populations and their source in situ populations of the endangered plant species Silene otites after 20-36 years of isolation. Furthermore, three additional wild populations were included in the analysis. Population genetic diversity and differentiation were analysed using AFLP markers. Genetic variation in the ex situ populations was lower than the variation found in the in situ populations. Strong differentiation (F-ST = 0.21-0.36) between corresponding in situ and ex situ populations was observed. Bayesian clustering approach also showed a distinct genetic separation between in situ and ex situ populations. The high genetic differentiation and loss of genetic diversity during spatial and temporal isolation in the ex situ populations can be attributable to small population sizes and unconscious selection during cultivation. Therefore, adequate sampling prior to ex situ cultivation and large effective population sizes are important to preserve genetic diversity. Near-natural cultivation allowing for generation overlap and interspecific competition without artificial selection is recommended as being best for the maintenance of the genetic constitution. KW - AFLP KW - botanical garden KW - conservation genetics KW - founder effect KW - population size Y1 - 2012 U6 - https://doi.org/10.1111/j.1095-8339.2011.01185.x SN - 0024-4074 VL - 168 IS - 1 SP - 64 EP - 75 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Khuroo, Anzar A. A1 - Reshi, Zafar A. A1 - Malik, Akhtar H. A1 - Weber, Ewald A1 - Rashid, Irfan A1 - Dar, G. H. T1 - Alien flora of India taxonomic composition, invasion status and biogeographic affiliations JF - Biological invasions : unique international journal uniting scientists in the broad field of biological invasions N2 - The wide knowledge gaps in invasion biology research that exist in the developing world are crucial impediments to the scientific management and global policymaking on biological invasions. In an effort to fill such knowledge gaps, we present here an inventory of the alien flora of India, based on systematic reviews and rigorous analyses of research studies (ca. 190) published over the last 120 years (1890-2010 AD), and updated with field records of the last two decades. Currently, the inventory comprises of 1,599 species, belonging to 842 genera in 161 families, and constitutes 8.5% of the total Indian vascular flora. The three most species-rich families are Asteraceae (134 spp.), Papilionaceae (114 spp.) and Poaceae (106 spp.), and the three largest genera are Eucalyptus (25 spp.), Ipomoea (22 spp.), and Senna (21 spp.). The majority of these species (812) have no report of escaping from cultivation. Of the remaining subset of 787 species, which have either escaped from intentional cultivation, or spread after unintentional introduction, casuals are represented by 57 spp., casual/naturalised by 114 spp., naturalised by 257 spp., naturalised/invasive by 134 spp., and invasive by 225 spp. Biogeographically, more than one-third (35%) of the alien flora in India has its native ranges in South America, followed by Asia (21%), Africa (20%), Europe (11%), Australia (8%), North America (4%); and cryptogenic (1%). The inventory is expected to serve as the scientific baseline on plant invasions in India, with implications for conservation of global biodiversity. KW - Biodiversity KW - Biological invasions KW - Alien plants KW - Taxonomy KW - Biogeography KW - India Y1 - 2012 U6 - https://doi.org/10.1007/s10530-011-9981-2 SN - 1387-3547 VL - 14 IS - 1 SP - 99 EP - 113 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Yarman, Aysu A1 - Gröbe, Glenn A1 - Neumann, Bettina A1 - Kinne, Mathias A1 - Gajovic-Eichelmann, Nenad A1 - Wollenberger, Ursula A1 - Hofrichter, Martin A1 - Ullrich, Rene A1 - Scheibner, Katrin A1 - Scheller, Frieder W. T1 - The aromatic peroxygenase from Marasmius rutola-a new enzyme for biosensor applications JF - Analytical & bioanalytical chemistry N2 - The aromatic peroxygenase (APO; EC 1.11.2.1) from the agraric basidomycete Marasmius rotula (MroAPO) immobilized at the chitosan-capped gold-nanoparticle-modified glassy carbon electrode displayed a pair of redox peaks with a midpoint potential of -278.5 mV vs. AgCl/AgCl (1 M KCl) for the Fe(2+)/Fe(3+) redox couple of the heme-thiolate-containing protein. MroAPO oxidizes aromatic substrates such as aniline, p-aminophenol, hydroquinone, resorcinol, catechol, and paracetamol by means of hydrogen peroxide. The substrate spectrum overlaps with those of cytochrome P450s and plant peroxidases which are relevant in environmental analysis and drug monitoring. In M. rotula peroxygenase-based enzyme electrodes, the signal is generated by the reduction of electrode-active reaction products (e.g., p-benzoquinone and p-quinoneimine) with electro-enzymatic recycling of the analyte. In these enzyme electrodes, the signal reflects the conversion of all substrates thus representing an overall parameter in complex media. The performance of these sensors and their further development are discussed. KW - Unspecific peroxygenase KW - Cytochrome P450 KW - Biosensors KW - Phenolic substances Y1 - 2012 U6 - https://doi.org/10.1007/s00216-011-5497-y SN - 1618-2642 VL - 402 IS - 1 SP - 405 EP - 412 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Türke, Manfred A1 - Andreas, Kerstin A1 - Gossner, Martin M. A1 - Kowalski, Esther A1 - Lange, Markus A1 - Boch, Steffen A1 - Socher, Stephanie A. A1 - Müller, Jörg A1 - Prati, Daniel A1 - Fischer, Markus A1 - Meyhöfer, Rainer A1 - Weisser, Wolfgang W. T1 - Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs? JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon. KW - myrmecochory KW - gastropodochory KW - Arion KW - slug KW - seed dispersal Y1 - 2012 U6 - https://doi.org/10.1086/663195 SN - 0003-0147 VL - 179 IS - 1 SP - 124 EP - 131 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Ziege, Madlen A1 - Hennige-Schulz, Carmen A1 - Muecksch, Frauke A1 - Bierbach, David A1 - Tiedemann, Ralph A1 - Streit, Bruno A1 - Plath, Martin T1 - A comparison of two methods to assess audience-induced changes in male mate choice JF - Current zoology N2 - Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because rivals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains unknown if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting). Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male's behavior. A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both stimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment. KW - Communication networks KW - Male mate choice KW - Non-independent mate choice KW - Sexual selection KW - Sperm competition risk KW - Audience effect Y1 - 2012 SN - 1674-5507 VL - 58 IS - 1 SP - 84 EP - 94 PB - Current Zoology CY - Beijing ER - TY - JOUR A1 - Winck, Flavia V. A1 - Riano-Pachon, Diego M. A1 - Sommer, Frederik A1 - Rupprecht, Jens A1 - Müller-Röber, Bernd T1 - The nuclear proteome of the green alga Chlamydomonas reinhardtii JF - Proteomics N2 - Nuclear proteins play a central role in regulating gene expression. Their identification is important for understanding how the nuclear repertoire changes over time under different conditions. Nuclear proteins are often underrepresented in proteomic studies due to the frequently low abundance of proteins involved in regulatory processes. So far, only few studies describing the nuclear proteome of plant species have been published. Recently, the genome sequence of the unicellular green alga Chlamydomonas reinhardtii has been obtained and annotated, allowing the development of further detailed studies for this organism. However, a detailed description of its nuclear proteome has not been reported so far. Here, we present an analysis of the nuclear proteome of the sequenced Chlamydomonas strain cc503. Using LC-MS/MS, we identified 672 proteins from nuclei isolates with a maximum 1% peptide spectrum false discovery rate. Besides well-known proteins (e.g. histones), transcription factors and other transcriptional regulators (e.g. tubby and HMG) were identified. The presence of protein motifs in nuclear proteins was investigated by computational tools, and specific over-represented protein motifs were identified. This study provides new insights into the complexity of the nuclear environment and reveals novel putative protein targets for further studies of nuclear mechanisms. KW - Nuclear proteomics KW - Plant proteomics KW - Systems biology KW - Transcription factor Y1 - 2012 U6 - https://doi.org/10.1002/pmic.201000782 SN - 1615-9853 VL - 12 IS - 1 SP - 95 EP - 100 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Wang, Wei-Hong A1 - Köhler, Barbara A1 - Cao, Feng-Qiu A1 - Liu, Guo-Wei A1 - Gong, Yuan-Yong A1 - Sheng, Song A1 - Song, Qi-Chao A1 - Cheng, Xiao-Yuan A1 - Garnett, Trevor A1 - Okamoto, Mamoru A1 - Qin, Rui A1 - Müller-Röber, Bernd A1 - Tester, Mark A1 - Liu, Lai-Hua T1 - Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis JF - New phytologist : international journal of plant science N2 - Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis. We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (Km of 7.55 mu M) transport system for urea-uptake by rice roots (Oryza sativa). A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a Km of c. 10 mu M in Xenopus oocytes. Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice. KW - high-affinity transporter KW - leaf senescence KW - nitrogen remobilization KW - OsDUR3 KW - overexpression KW - rice plant KW - urea transport and utilization Y1 - 2012 U6 - https://doi.org/10.1111/j.1469-8137.2011.03929.x SN - 0028-646X VL - 193 IS - 2 SP - 432 EP - 444 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Silva-Iturriza, Adriana A1 - Ketmaier, Valerio A1 - Tiedemann, Ralph T1 - Profound population structure in the Philippine Bulbul Hypsipetes philippinus (Pycnonotidae, Ayes) is not reflected in its Haemoproteus haemosporidian parasite JF - Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics and infectious diseases (MEEGID) N2 - In this study we used molecular markers to screen for the occurrence and prevalence of the three most common haemosporidian genera (Haemoproteus, Plasmodium, and Leucocytozoon) in blood samples of the Philippine Bulbul (Hypsipetes philippinus), a thrush-size passerine bird endemic to the Philippine Archipelago. We then used molecular data to ask whether the phylogeographic patterns in this insular host-parasite system might follow similar evolutionary trajectories or not. We took advantage of a previous study describing the pattern of genetic structuring in the Philippine Bulbul across the Central Philippine Archipelago (6 islands, 7 populations and 58 individuals; three mitochondrial DNA genes). The very same birds were here screened for the occurrence of parasites by species-specific PCR assays of the mitochondrial cytochrome b gene (471 base pairs). Twenty-eight out of the 58 analysed birds had Haemoproteus (48%) infections while just 2% of the birds were infected with either Leucocytozoon or Plasmodium. Sixteen of the 28 birds carrying Haemoproteus had multiple infections. The phylogeography of the Philippine Bulbul mostly reflects the geographical origin of samples and it is consistent with the occurrence of two different subspecies on (1) Semirara and (2) Carabao, Boracay, North Gigante, Panay, and Negros, respectively. Haemoproteus phylogeography shows very little geographical structure, suggesting extensive gene flow among locations. While movements of birds among islands seem very sporadic, we found co-occurring evolutionary divergent parasite lineages. We conclude that historical processes have played a major role in shaping the host phylogeography, while they have left no signature in that of the parasites. Here ongoing population processes, possibly multiple reinvasions mediated by other hosts, are predominant. KW - Haemoproteus KW - Hypsipetes philippinus KW - Comparative phylogeography KW - mtDNA Y1 - 2012 U6 - https://doi.org/10.1016/j.meegid.2011.10.024 SN - 1567-1348 VL - 12 IS - 1 SP - 127 EP - 136 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Scheffler, Christiane A1 - Obermüller, Janina T1 - Development of fat distribution patterns in children and its association with the type of body shape assessed by the Metric-Index JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - The present cross-sectional anthropometric study evaluates new approaches in preventing overweight in children. Anthropometric data were obtained in 289 German children (146 boys, 143 girls) aged 6-11 years and 41 20-29 year old German female students for describing the type of body shape by Metric-Index (thoracic breadth, thoracic depth, height). The data were correlated with 15 fat layers measured with a lipometer with Principal Component Analyses and ANOVA. In females the android respectively gynoid type of body shape was significantly associated with the pyknomorphic respectively leptomorphic type. The study demonstrates that this pattern is established by an age of 8 years, when the earliest maturing children start to enter puberty. This pattern can be used to check the individual's risk of overweight and to recommend preventive healthcare interventions. KW - school children KW - type of body shape KW - risk of overweight KW - prevention Y1 - 2012 U6 - https://doi.org/10.1127/0003-5548/2011/0138 SN - 0003-5548 VL - 69 IS - 1 SP - 45 EP - 55 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Sarauli, David A1 - Riedel, Marc A1 - Wettstein, Christoph A1 - Hahn, Robert A1 - Stiba, Konstanze A1 - Wollenberger, Ursula A1 - Leimkühler, Silke A1 - Schmuki, Patrik A1 - Lisdat, Fred T1 - Semimetallic TiO2 nanotubes new interfaces for bioelectrochemical enzymatic catalysis JF - Journal of materials chemistry N2 - Different self-organized TiO2 nanotube structures are shown to represent new interfaces for the achievement of bioelectrochemical enzymatic catalysis involving redox proteins and enzymes without further surface modification or the presence of mediators. Y1 - 2012 U6 - https://doi.org/10.1039/c2jm16427b SN - 0959-9428 VL - 22 IS - 11 SP - 4615 EP - 4618 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Omranian, Nooshin A1 - Müller-Röber, Bernd A1 - Nikoloski, Zoran T1 - PageRank-based identification of signaling crosstalk from transcriptomics data the case of Arabidopsis thaliana JF - Molecular BioSystems N2 - The levels of cellular organization, from gene transcription to translation to protein-protein interaction and metabolism, operate via tightly regulated mutual interactions, facilitating organismal adaptability and various stress responses. Characterizing the mutual interactions between genes, transcription factors, and proteins involved in signaling, termed crosstalk, is therefore crucial for understanding and controlling cells' functionality. We aim at using high-throughput transcriptomics data to discover previously unknown links between signaling networks. We propose and analyze a novel method for crosstalk identification which relies on transcriptomics data and overcomes the lack of complete information for signaling pathways in Arabidopsis thaliana. Our method first employs a network-based transformation of the results from the statistical analysis of differential gene expression in given groups of experiments under different signal-inducing conditions. The stationary distribution of a random walk (similar to the PageRank algorithm) on the constructed network is then used to determine the putative transcripts interrelating different signaling pathways. With the help of the proposed method, we analyze a transcriptomics data set including experiments from four different stresses/signals: nitrate, sulfur, iron, and hormones. We identified promising gene candidates, downstream of the transcription factors (TFs), associated to signaling crosstalk, which were validated through literature mining. In addition, we conduct a comparative analysis with the only other available method in this field which used a biclustering-based approach. Surprisingly, the biclustering-based approach fails to robustly identify any candidate genes involved in the crosstalk of the analyzed signals. We demonstrate that our proposed method is more robust in identifying gene candidates involved downstream of the signaling crosstalk for species for which large transcriptomics data sets, normalized with the same techniques, are available. Moreover, unlike approaches based on biclustering, our approach does not rely on any hidden parameters. Y1 - 2012 U6 - https://doi.org/10.1039/c2mb05365a SN - 1742-206X VL - 8 IS - 4 SP - 1121 EP - 1127 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Sarauli, David A1 - Xu, Chenggang A1 - Dietzel, Birgit A1 - Stiba, Konstanze A1 - Leimkühler, Silke A1 - Schulz, Burkhard A1 - Lisdat, Fred T1 - Thin films of substituted polyanilines interactions with biomolecular systems JF - Soft matter N2 - We use substituted polyanilines for the construction of new polymer electrodes for interaction studies with the redox protein cytochrome c (cyt c) and the enzyme sulfite oxidase (SO). For these purposes four different polyaniline copolymers are chemically synthesized. Three of them are copolymers, containing 2-methoxyaniline-5-sulfonic acid with variable ratios of aniline; the fourth copolymer consists of 3-amino-benzoic acid and aniline. The results show that all polymers are suitable for being immobilized as thin stable films on gold wire and indium tin oxide (ITO) electrode surfaces from DMSO solution. This can be demonstrated by cyclic voltammetry and UV-Vis spectroscopy measurements. Moreover, cyt c can be electrochemically detected not only in solution, but also immobilized on top of the polymer films. Furthermore, the appearance of a significant catalytic current has been demonstrated for the sulfonated polyanilines, when the polymer-coated protein electrode is being measured upon addition of sulfite oxidase, confirming the establishment of a bioanalytical signal chain. Best results have been obtained for the polymer with highest sulfonation grade. The redox switching of the polymer by the enzymatic reaction can also be analyzed by following the spectral properties of the polymer electrode. Y1 - 2012 U6 - https://doi.org/10.1039/c2sm07261k SN - 1744-683X VL - 8 IS - 14 SP - 3848 EP - 3855 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Krause, E. Tobias A1 - Liesenjohann, Thilo T1 - Predation pressure and food abundance during early life alter risk-taking behaviour and growth of guppies (Poecilia reticulata) JF - Behaviour : an international journal of behavioural biology N2 - The trade-off between predation risk and the need to feed is one of the major constraints animals have to cope with. Virtually all animals have a higher risk of being preyed upon when being active (e.g., searching for food or mating partners), compared with being inactive (e.g., staying at their burrows, nests, etc.). Yet, staying safe leads to a higher risk of starvation and may reduce reproductive success and body growth. Hence selection on behaviour optimizing the search, handling and digestion of food while avoiding the risk of predation is strong and should lead to strategies maximising survival chances and inclusive fitness. These facts call for integrative studies manipulating both, abundance of food and predation risk in a factorial set up, analysing the effects of both factors on behaviour and physiological parameters. We present results of a 2 x 2 factorial experiment, manipulating risk of predation and food abundance in guppies. We found that the two factors have an additive effect on body growth, but that predation risk by a pike cichlid is the main factor affecting the expression of behavioural strategies in guppies. Low food availability and high predation risk led to lower body growth. High predation risk affected swimming depth and risk sensitivity of guppies and might represent adaptive behavioural changes to the environmental context experienced in early life. Our study shows that integrative studies, analysing multiple interdependent and interconnected factors in the wild and in the lab are needed to further understand animal behaviour and development. KW - predation KW - food abundance KW - nutritional stress KW - risk taking KW - early development KW - developmental stress KW - guppy KW - Poecilia reticulata Y1 - 2012 U6 - https://doi.org/10.1163/156853912X623748 SN - 0005-7959 VL - 149 IS - 1 SP - 1 EP - 14 PB - Brill CY - Leiden ER - TY - JOUR A1 - Janewa, Vanessa Schönfeld A1 - Ghosh, Arnab A1 - Scheffler, Christiane T1 - Comparison of BMI and percentage of body fat of Indian and German children and adolescents JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Today, serious health problems as overweight and obesity are not just constricted to the developed world, but also increase in the developing countries (Prentice 2006, Ramachandram et al. 2002). Focusing on this issue, BMI and percentage of body fat were compared in 2094 schoolchildren from two cross-sectional studies from India and Germany investigated in 2008 and 2009. The German children are in all age groups significantly taller, whereas the Indian children show higher values in BMI (e.g. 12 years: Indian: around 22 kg/m(2); German: around 19 kg/m(2)) and in the percentage of body fat (e.g. 12 years: Indian: around 27 %; German: around 18-20%) in most of the investigated age groups. The Indian children have significantly higher BMI between 10 and 13 (boys) respectively 14 years (girls). Indian children showed significant higher percentage of body fat between 10 and 15 years (boys) and between 8 and 16 years (girls). The difference in overweight between Indian and German children was strongest at 11 (boys) and 12 (girls) years: 70 % of the Indian but 20% of the German children were classified as overweight. In countries such as India that undergo nutritional transition, a rapid increase in obesity and overweight is observed. In contrast to the industrialized countries, the risk of overweight in developing countries is associated with high socioeconomic status. Other reasons of the rapid increase of overweight in the developing countries caused by different environmental or genetic factors are discussed. KW - Overweight KW - school children KW - industrial and developing countries Y1 - 2012 U6 - https://doi.org/10.1127/0003-5548/2012/0170 SN - 0003-5548 VL - 69 IS - 2 SP - 175 EP - 187 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Hermanussen, Michael A1 - Lieberman, Leslie Su A1 - Janewa, V. Schoenfeld A1 - Scheffler, Christiane A1 - Ghosh, Arunava A1 - Bogin, Barry A1 - Godina, Elena A1 - Kaczmarek, M. A1 - El-Shabrawi, M. A1 - Salama, E. E. A1 - Rühli, Frank J. A1 - Staub, Kaspar A1 - Woitek, U. A1 - Blaha, Pawel A1 - Aßmann, Christian A1 - van Buuren, Stef A1 - Lehmann, A. A1 - Satake, T. A1 - Thodberg, H. H. A1 - Jopp, E. A1 - Kirchengast, S. A1 - Tutkuviene, J. A1 - McIntyre, M. H. A1 - Wittwer-Backofen, U. A1 - Boldsen, Jesper L. A1 - Martin, D. D. A1 - Meier, J. T1 - Diversity in auxology between theory and practice JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Auxology has developed from mere describing child and adolescent growth into a vivid and interdisciplinary research area encompassing human biologists, physicians, social scientists, economists and biostatisticians. The meeting illustrated the diversity in auxology, with the various social, medical, biological and biostatistical aspects in studies on child growth and development. KW - child growth KW - adolescent growth KW - child development KW - height KW - weight KW - body mass KW - socio-economic environment Y1 - 2012 U6 - https://doi.org/10.1127/0003-5548/2012/0133 SN - 0003-5548 VL - 69 IS - 2 SP - 159 EP - 174 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Roesel, Stefan A1 - Grossart, Hans-Peter T1 - Contrasting dynamics in activity and community composition of free-living and particle-associated bacteria in spring JF - Aquatic microbial ecology : international journal N2 - Phytoplankton development affects the community structure and dynamics of freshwater bacteria by changing the availability of nutrients, algal exudates and biological surfaces. To elucidate these effects of phytoplankton development in spring in oligotrophic Lake Stechlin (Germany), we measured limnological and biological parameters, including the bacterial community composition (BCC), at the depth of the highest chlorophyll a concentration. To increase the resolution of BCC measurements, we separated particle-associated (PA) and free-living (FL) bacteria using serial filtration through 5.0 and 0.2 mu m pore size filters, respectively. The BCC of ultramicrobacteria was also determined by collecting the 0.2 mu m filtrate on 0.1 mu m filters. Changes in the community composition of Bacteria and particularly of Actinobacteria, one of the most important bacterial groups in temperate freshwater habitats, were studied via DGGE analysis of PCR-amplified 16S rRNA gene fragments. Patterns in BCC dynamics of FL Bacteria and Actinobacteria remained fairly constant throughout the study period, while patterns of PA Bacteria were more variable over time. At the breakdown of the diatom spring bloom, bacterial production and abundance sharply increased, indicating a close coupling between heterotrophic bacteria and algal detritus. The succession in BCC revealed life-style dependent patterns related to specific environmental variables. Our results indicate independent dynamics of PA and FL Bacteria as well as Actinobacteria during succession of phytoplankton spring blooms. These differences in bacterial lifestyle can only be resolved when the PA and FL fractions of microorganisms are separated. KW - Bacterial community composition (BCC) KW - Spring bloom KW - Bacteria-phytoplankton coupling KW - Pollen KW - Free-living and particle-associated bacteria KW - Lake Stechlin Y1 - 2012 U6 - https://doi.org/10.3354/ame01568 SN - 0948-3055 VL - 66 IS - 2 SP - 169 EP - + PB - Institute of Mathematical Statistics CY - Oldendorf Luhe ER - TY - JOUR A1 - Braun, Christina A1 - Mustafa, Osama A1 - Nordt, Anja A1 - Pfeiffer, Simone A1 - Peter, Hans-Ulrich T1 - Environmental monitoring and management proposals for the Fildes Region, King George Island, Antarctica JF - Polar research : a Norwegian journal of Polar research N2 - The Antarctic terrestrial environment is under increasing pressure from human activities. The Fildes Region is characterized by high biodiversity, but is also a major logistic centre for the northern Antarctic Peninsula. Different interests, from scientific research, nature conservation, protection of geological and historical values, station operations, transport logistics and tourism, regularly overlap in space and time. This has led to increasing conflict among the multiple uses of the region and breaches of the legal requirements for environmental protection that apply in the area. The aim of this study was to assess the impacts of human activities in the Fildes Region by monitoring the distribution of bird and seal breeding sites and recording human activities and their associated environmental impacts. Data from an initial monitoring period 2003-06 were compared with data from 2008-10. We observed similar or increased levels of air, land and ship traffic, but fewer violations of overflight limits near Antarctic Specially Protected Area No. 150 Ardley Island. Open waste dumping and oil contamination are still major environmental impacts. Scientific and outdoor leisure activities undertaken by station personnel are more frequent than tourist activities and are likely to have a commensurate level of environmental impact. Despite the initial success of some existing management measures, it is essential that scientific and environmental values continue to be safeguarded, otherwise environmental impacts will increase and the habitat will be further degraded. We argue that the Fildes Region should be considered for designation as an Antarctic Specially Managed Area, a measure that has proven effective for environmental management of vulnerable areas of the Antarctic. KW - human impact KW - Antarctic KW - Fildes Region KW - environmental management KW - Antarctic Specially Managed Area KW - protected area Y1 - 2012 U6 - https://doi.org/10.3402/polar.v31i0.18206 SN - 0800-0395 VL - 31 IS - 209 PB - Co-Action Publ. CY - Jarfalla ER - TY - JOUR A1 - Seifan, Merav A1 - Seifan, Tal A1 - Jeltsch, Florian A1 - Tielboerger, Katja T1 - Combined disturbances and the role of their spatial and temporal properties in shaping community structure JF - Perspectives in plant ecology, evolution and systematics N2 - Disturbances are characteristic for many ecosystems. However, we still lack generalizations concerning their role in shaping communities, particularly when disturbances co-occur. To study such effects, we used a novel modeling approach that is unrestricted by a priori tradeoffs among specific plant traits, except for those generated by allocation principles. Thus, trait combinations were emergent properties associated with biotic and abiotic constraints. Specifically, we asked which traits dominate under specific disturbance regimes, whether single and combined disturbance regimes promote similar trait tradeoffs and how complex disturbance regimes affect species richness and functional diversity. Overall, disturbances' temporal properties governed the outcome of combined disturbances and were a stronger assortative force than spatial disturbance properties: low temporal predictability decreased seed-dispersability and dormancy, but increased competitive ability and disturbance tolerance. Evidence for tradeoffs between different colonization modes and between dormancy and disturbance tolerance were found, while surprisingly, the widely accepted colonization-competition tradeoff was not generated. Diversity was highest at intermediate disturbance intensity, but decreased monotonically with increasing unpredictability. In accordance with our results, future models should avoid restrictive assumptions about tradeoffs to generate robust and more general predictions about the role of disturbances for community dynamics. KW - Intermediate disturbance hypothesis KW - Coexistence KW - Environmental heterogeneity KW - Competition-colonization KW - Plant community KW - Individual-based model Y1 - 2012 U6 - https://doi.org/10.1016/j.ppees.2011.11.003 SN - 1433-8319 VL - 14 IS - 3 SP - 217 EP - 229 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Girndt, Antje A1 - Riesch, Rüdiger A1 - Schröder, Christiane A1 - Sehlupp, Ingo A1 - Plath, Martin A1 - Tiedemann, Ralph T1 - Multiple paternity in different populations of the sailfin molly, Poecilia latipinna JF - Animal biology N2 - Rates of multiple paternities were investigated in the sailfin molly (Poecilia latipinna), using eight microsatellite loci. Genotyping was performed for offspring and mothers in 40 broods from four allopatric populations from the south-eastern U.S.A. along a geographic stretch of 1200 km in west-east direction and approximately 200 km from north to south. No significant differences regarding rates of multiple paternities were found between populations despite sample populations stemming from ecologically divergent habitats. Even the most conservative statistical approach revealed a minimum of 70% of the broods being sired by at least two males, with an average of 1.80-2.95 putative fathers per brood. Within broods, one male typically sired far more offspring than would be expected under an assumed equal probability of all detected males siring offspring. KW - Promiscuity KW - mate choice KW - multiple paternity KW - sperm competition KW - Poeciliidae Y1 - 2012 U6 - https://doi.org/10.1163/157075611X618192 SN - 1570-7555 VL - 62 IS - 3 SP - 245 EP - 262 PB - Brill CY - Leiden ER - TY - JOUR A1 - Blüthgen, Nico A1 - Dormann, Carsten F. A1 - Prati, Daniel A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Hoelzel, Norbert A1 - Alt, Fabian A1 - Boch, Steffen A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Müller, Jörg A1 - Nieschulze, Jens A1 - Renner, Swen C. A1 - Schöning, Ingo A1 - Schumacher, Uta A1 - Socher, Stephanie A. A1 - Wells, Konstans A1 - Birkhofer, Klaus A1 - Buscot, Francois A1 - Oelmann, Yvonne A1 - Rothenwöhrer, Christoph A1 - Scherber, Christoph A1 - Tscharntke, Teja A1 - Weiner, Christiane N. A1 - Fischer, Markus A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. T1 - A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Land use is increasingly recognized as a major driver of biodiversity and ecosystem functioning in many current research projects. In grasslands, land use is often classified by categorical descriptors such as pastures versus meadows or fertilized versus unfertilized sites. However, to account for the quantitative variation of multiple land-use types in heterogeneous landscapes, a quantitative, continuous index of land-use intensity (LUI) is desirable. Here we define such a compound, additive LUI index for managed grasslands including meadows and pastures. The LUI index summarizes the standardized intensity of three components of land use, namely fertilization, mowing, and livestock grazing at each site. We examined the performance of the LUI index to predict selected response variables on up to 150 grassland sites in the Biodiversity Exploratories in three regions in Germany(Alb, Hainich, Schorlheide). We tested the average Ellenberg nitrogen indicator values of the plant community, nitrogen and phosphorus concentration in the aboveground plant biomass, plant-available phosphorus concentration in the top soil, and soil C/N ratio, and the first principle component of these five response variables. The LUI index significantly predicted the principal component of all five response variables, as well as some of the individual responses. Moreover, vascular plant diversity decreased significantly with LUI in two regions (Alb and Hainich). Inter-annual changes in management practice were pronounced from 2006 to 2008, particularly due to variation in grazing intensity. This rendered the selection of the appropriate reference year(s) an important decision for analyses of land-use effects, whereas details in the standardization of the index were of minor importance. We also tested several alternative calculations of a LUI index, but all are strongly linearly correlated to the proposed index. The proposed LUI index reduces the complexity of agricultural practices to a single dimension and may serve as a baseline to test how different groups of organisms and processes respond to land use. In combination with more detailed analyses, this index may help to unravel whether and how land-use intensities, associated disturbance levels or other local or regional influences drive ecological processes. KW - Agro-ecosystems KW - Biodiversity exploratories KW - Grassland management KW - Land-use impacts KW - Livestock density KW - Meadows KW - Nitrogen KW - Pastures Y1 - 2012 U6 - https://doi.org/10.1016/j.baae.2012.04.001 SN - 1439-1791 VL - 13 IS - 3 SP - 207 EP - 220 PB - Elsevier CY - Jena ER - TY - INPR A1 - Wannicke, Nicola A1 - Endres, S. A1 - Engel, A. A1 - Grossart, Hans-Peter A1 - Nausch, M. A1 - Unger, J. A1 - Voss, Martin T1 - Response of nodularia spumigena to pCO(2) - Part 1: Growth, production and nitrogen cycling T2 - Biogeosciences N2 - Heterocystous cyanobacteria of the genus Nodularia form extensive blooms in the Baltic Sea and contribute substantially to the total annual primary production. Moreover, they dispense a large fraction of new nitrogen to the ecosystem when inorganic nitrogen concentration in summer is low. Thus, it is of ecological importance to know how Nodularia will react to future environmental changes, in particular to increasing carbon dioxide (CO2) concentrations and what consequences there might arise for cycling of organic matter in the Baltic Sea. Here, we determined carbon (C) and dinitrogen (N-2) fixation rates, growth, elemental stoichiometry of particulate organic matter and nitrogen turnover in batch cultures of the heterocystous cyanobacterium Nodularia spumigena under low (median 315 mu atm), mid (median 353 mu atm), and high (median 548 mu atm) CO2 concentrations. Our results demonstrate an overall stimulating effect of rising pCO(2) on C and N-2 fixation, as well as on cell growth. An increase in pCO(2) during incubation days 0 to 9 resulted in an elevation in growth rate by 84 +/- 38% (low vs. high pCO(2)) and 40 +/- 25% (mid vs. high pCO(2)), as well as in N-2 fixation by 93 +/- 35% and 38 +/- 1%, respectively. C uptake rates showed high standard deviations within treatments and in between sampling days. Nevertheless, C fixation in the high pCO(2) treatment was elevated compared to the other two treatments by 97% (high vs. low) and 44% (high vs. mid) at day 0 and day 3, but this effect diminished afterwards. Additionally, elevation in carbon to nitrogen and nitrogen to phosphorus ratios of the particulate biomass formed (POC : POP and PON : POP) was observed at high pCO(2). Our findings suggest that rising pCO(2) stimulates the growth of heterocystous diazotrophic cyanobacteria, in a similar way as reported for the non-heterocystous diazotroph Trichodesmium. Implications for biogeochemical cycling and food web dynamics, as well as ecological and socio-economical aspects in the Baltic Sea are discussed. Y1 - 2012 U6 - https://doi.org/10.5194/bg-9-2973-2012 SN - 1726-4170 VL - 9 IS - 8 SP - 2973 EP - 2988 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Piepho, Maike A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Phytoplankton sterol contents vary with temperature, phosphorus and silicate supply a study on three freshwater species JF - European journal of phycology N2 - The understanding of environmentally induced changes in the biochemical composition of phytoplankton species is of great importance in both physiological studies and ecological food web research. In extensive laboratory experiments we tested the influence of two different temperatures (10 degrees C and 25 degrees C) and a phosphorus supply gradient on the sterol concentrations of the three freshwater phytoplankton species Scenedesmus quadricauda, Cryptomonas ovata and Cyclotella meneghiniana. The diatom C. meneghiniana was additionally exposed to a silicate gradient. In two separate experiments we analysed (1) possible interactive effects of temperature and phosphorus supply and (2) the effect of four phosphorus levels and three silicate levels on algal sterol concentrations. We observed that sterol concentrations were higher at 25 degrees C than at 10 degrees C in S. quadricauda and C. meneghiniana, but were not affected by temperature in C. ovata. Interactive effects of temperature and phosphorus supply on sterol concentrations were found in C. meneghiniana. This presumably was due to the bioconversion of one sterol (24-methylenecholesterol) into another (22-dihydrobrassicasterol). Increasing phosphorus supply resulted in species-specific effects on sterol concentrations, viz. an optimum curve response in S. quadricauda, a saturation curve response in C. meneghiniana and no change in sterol concentration in C. ovata. Effects of silicate supply on the sterols of C. meneghiniana equalled the effects of phosphorus supply. Albeit we did not observe a general trend in the three phytoplankton species tested, we conclude that sterol concentrations of phytoplankton are strongly affected by temperature and nutrient supply. Interactive effects point out the importance of taking into account more than just one environmental factor when assessing the effects of environmentally induced changes on phytoplankton sterol concentrations. KW - algae KW - Chlorophyta KW - Cryptomonas KW - Cryptophyta KW - Cyclotella KW - diatoms KW - phosphorus KW - Scenedesmus KW - silicate KW - sterols KW - temperature Y1 - 2012 U6 - https://doi.org/10.1080/09670262.2012.665484 SN - 0967-0262 VL - 47 IS - 2 SP - 138 EP - 145 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Li, Jian A1 - Wang, Zi-Neng A1 - Chen, You-Peng A1 - Dong, Yun-Peng A1 - Mao, Xiao-Min A1 - Hocher, Berthold T1 - Association of fetal but not maternal P-glycoprotein C3435T polymorphism with fetal growth and birth weight, a possible risk factor for cardiovascular diseases in later life JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: The multidrug transporter P-glycoprotein (PGP) is expressed in the human placenta. In particular the C3435T ABCB1 polymorphism was associated with altered tissue expression of PGP in the human placenta. However, the potential functional impact of this polymorphism on the offspring is unknown so far. Methods: We analyzed the impact of the ABCB1/C3435T polymorphism on fetal growth in 262 mother/child pairs. Fetal growth was assessed by differential ultrasound examination of the fetal body prior to birth and by measuring birth weight. Results: The maternal ABCB1/C3435T polymorphism showed no trend for an association with birth weight or any ultrasound parameter describing late gestational fetal body shape. Genotyping the newborns, however, demonstrated that newborns carrying two copies of the T allele had a birth weight of 3176.39 g, whereas CT and CC newborns had a birth weight of 3345.04 g (p = 0.022). Adjusting for gestational age at delivery, child's gender, maternal BM1, maternal age and body weight at delivery confirmed this finding (p = 0.009). Considering gestational day of late ultrasound examination, gestational age at delivery, child's gender, maternal BMI, maternal age and maternal body weight at delivery, the fetal ABCB1/C3435T genotype revealed likewise a significant negative correlation with abdominal diameter and abdominal circumference (R-2 = 0.538, p = 0.010 and R-2 = 0.534, p = 0.005, respectively). Conclusions: Low birth weight may be a risk factor for cardiovascular diseases in later life. The fetal ABCB1/C3435T gene polymorphism may contribute to this risk. Since PGP controls transport of various biological agents, we suggest that PGP is involved in the transport of biological agents to the fetus that are important for normal fetal growth. Y1 - 2012 U6 - https://doi.org/10.7754/Clin.Lab.2012.110920 SN - 1433-6510 VL - 58 IS - 9-10 SP - 1085 EP - 1089 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - Gärtner, Mirijam A1 - Nottebrock, Henning A1 - Fourie, Helanya A1 - Privett, Sean D. J. A1 - Richardson, David M. T1 - Plant invasions, restoration, and economics perspectives from South African fynbos JF - Perspectives in plant ecology, evolution and systematics N2 - Restoration is gaining importance in the management of plant invasions. As the success of restoration projects is frequently determined by factors other than ecological ones, we explored the ecological and financial feasibility of active restoration on three different invaded sites in South Africa's Cape Floristic Region. The aim of our study was to identify cost-effective ways of restoring functional native ecosystems following invasion by alien plants. Over three years we evaluated different restoration approaches using field trials and experimental manipulations (i.e. mechanical clearing, burning, different soil restoration techniques and sowing of native species) to reduce elevated soil nutrient levels and to re-establish native fynbos communities. Furthermore we investigated the possibility of introducing native fynbos species that can be used for sustainable harvesting to create an incentive for restoration on private land. Diversity and evenness of native plant species increased significantly after restoration at all three sites, whereas cover of alien plants decreased significantly, confirming that active restoration was successful. However, sowing of native fynbos species had no significant effect on native cover, species richness, diversity or evenness in the Acacia thicket and Kikuyu field, implying that the ecosystem was sufficiently resilient to allow autogenic recovery following clearing and burning of the invasive species. Soil restoration treatments resulted in an increase of available nitrogen in the Acacia thicket, but had no significant effects in the Eucalyptus plantation. However, despite elevated available soil nitrogen levels, native species germinated irrespective whether sown or unsown (i.e. regeneration from the soil seed bank). Without active introduction of native species, native grasses, forbs and other shrubs would have dominated, and proteoids and ericoids (the major fynbos growth forms) would have been under-represented. The financial analysis shows that income from flower harvesting following active restoration consistently outweighs income following passive restoration, but that the associated increase in income does not always justify the higher costs. We conclude that active restoration can be effective and financially feasible when compared to passive restoration, depending on the density of invasion. Active restoration of densely invaded sites may therefore only be justifiable if the target area is in a region of high conservation priority. KW - Biological invasions KW - Cost-benefit analysis KW - Degradation KW - Exotic species KW - Flower harvesting KW - Rehabilitation Y1 - 2012 U6 - https://doi.org/10.1016/j.ppees.2012.05.001 SN - 1433-8319 VL - 14 IS - 5 SP - 341 EP - 353 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Wildish, J. A1 - Pavesi, Laura A1 - Ketmaier, Valerio T1 - Talitrid amphipods (Crustacea: Amphipoda: Talitridae) and the driftwood ecological niche a morphological and molecular study JF - Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor & Francis   1.1967 - N2 - Coastal regions of the North East Atlantic and Mediterranean Seas have four known species of driftwood talitrids. Records are extremely scanty, often limited to the type locality and dating to 1950. We were able to study three of them, all belonging to the genus Macarorchestia, using fresh and archived samples including type material. Allometric and molecular analyses support: (1) a close relationship among all the three classically defined Macarorchestia species, (2) Macarorchestia was well separated from non-driftwood taxa, and (3) a putative new driftwood talitrid discovered during this study was not closely related to Macarorchestia. Genetic divergence between the new species and Macarorchestia remyi is as high as the average distance among a number of talitrid species included in the study for comparison. A key is provided to identify all three of the presently known species of Macarorchestia, using morphological characters employed in the allometric study. KW - Macarorchestia remyi KW - Macarorchestia roffensis KW - Macarorchestia martini KW - Driftwood habitat KW - COI-DNA barcoding KW - allometry Y1 - 2012 U6 - https://doi.org/10.1080/00222933.2012.717971 SN - 0022-2933 VL - 46 IS - 43-44 SP - 2677 EP - 2700 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Uhlig, Katja A1 - Madaboosi, Narayanan A1 - Schmidt, Stephan A1 - Jäger, Magnus S. A1 - Rose, Jürgen A1 - Duschl, Claus A1 - Volodkin, Dmitry V. T1 - 3d localization and diffusion of proteins in polyelectrolyte multilayers JF - Soft matter N2 - The interaction of diverse biomaterials with surfaces is more crucial than ever for biomedical applications to ensure efficiency and reproducibility. Very interesting surface materials are micrometer-thick polyelectrolyte multilayers. Not only their surface but also the bulk can be loaded with biomaterials like proteins or DNA for various purposes. Therefore, we established a method to analyze the lateral and vertical distribution of fluorescently labelled proteins of various size and charge in polyelectrolyte films composed of poly(L-lysine) and hyaluronic acid by confocal laser scanning microscopy. This approach enables us to measure the diffusion coefficients of the proteins via fluorescence recovery after photobleaching as a function of their vertical position in the film and facilitates the understanding of molecular interactions in the film with a high resolution in both space and time. As a result, we confirm that protein loading in the film is driven by electrostatic interactions - uncharged dextran molecules of 10 and 500 kDa do not diffuse into the film. Proteins of different sizes (3-11 nm) can diffuse relatively fast (D = 2-4 mm(2) s(-1)) independent of their net charge, indicating complex interpolymer interactions. This approach is a new powerful experimental tool to design the polyelectrolyte multilayers for bio-applications by finding a relationship between intermolecular interactions and mobility and availability of biomolecules to biological samples (e.g. cells) or detection units (e.g. biosensors). Y1 - 2012 U6 - https://doi.org/10.1039/c2sm26500a SN - 1744-683X VL - 8 IS - 47 SP - 11786 EP - 11789 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Schneider, Tobias A1 - Kohl, Benjamin A1 - Sauter, Tilman A1 - Kratz, Karl A1 - Lendlein, Andreas A1 - Ertel, Wolfgang A1 - Schulze-Tanzil, Gundula T1 - Influence of fiber orientation in electrospun polymer scaffolds on viability, adhesion and differentiation of articular chondrocytes JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Degradable polymers with a tailorable degradation rate might be promising candidate materials for biomaterial-based cartilage repair. In view of the poor intrinsic healing capability of cartilage, implantation of autologous chondrocytes seeded on a biocompatible slow degrading polymer might be an encouraging approach to improve cartilage repair in the future. This study was undertaken to test if the fiber orientation (random versus aligned) of two different degradable polymers and a polymer intended for long term applications could influence primary articular chondrocytes growth and ultrastructure. A degradable copoly(ether) esterurethane (PDC) was synthesized via co-condensation of poly(p-dioxanone) diol and poly(epsilon-caprolactone) diol using an aliphatic diisocyanate as linker. Poly(p-dioxanone) (PPDO) was applied as commercially available degradable polymer, while polyetherimide (PEI) was chosen as biomaterial enabling surface functionalization. The fibrous scaffolds of PDC and PPDO were obtained by electrospinning using 1,1,1,3,3,3 hexafluoro-2-propanol (HFP), while for PEI dimethyl acetamide (DMAc) was applied as solvent. Primary porcine articular chondrocytes were seeded at different cell densities on the fibrous polymer scaffolds and analyzed for viability (fluorescein diacetate/ethidiumbromide staining), for type II collagen synthesis (immunolabelling), ultrastructure and orientation on the fibers (SEM: scanning electron microscopy). Vital chondrocytes adhered on all electrospun scaffolds irrespective of random and aligned topologies. In addition, the chondrocytes produced the cartilage-specific type II collagen on all tested polymer topologies suggesting their differentiated functions. SEM revealed an almost flattened chondrocytes shape on scaffolds with random fiber orientation: whereby chondrocytes growth remained mainly restricted to the scaffold surface. On aligned fibers the chondrocytes exhibited a more spindle-shaped morphology with rougher cell surfaces but only a minority of the cells aligned according to the fibers. As a next step the reduction of the fiber diameter of electrospun scaffolds should be addressed as an important parameter to mimic cartilage ECM structure. KW - Chondrocytes KW - electrospinning KW - scaffold KW - differentiation KW - multiblock copolymer Y1 - 2012 U6 - https://doi.org/10.3233/CH-2012-1608 SN - 1386-0291 VL - 52 IS - 2-4 SP - 325 EP - 336 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Welker, Martin A1 - Dittmann-Thünemann, Elke A1 - von Doehren, Hans ED - Hopwood, DA T1 - Cyanobacteria as a source of natural products JF - Methods in enzymology JF - Methods in Enzymology N2 - Cyanobacteria or blue-green algae from various environments have been recognized as sources of a variety of bioactive metabolites. Strategies of strain isolation from aquatic habitats, and cultivation and harvesting for metabolite production are described. Strategies for screening of compounds are discussed, including their direct MALDI-TOF mass spectrometric detection in whole cells. Genetic approaches including genomic mining, mutagenesis including transcriptional activation, heterologous expression, and in vitro. reconstitution of pathways are presented. Y1 - 2012 SN - 978-0-12-404634-4 U6 - https://doi.org/10.1016/B978-0-12-404634-4.00002-4 SN - 0076-6879 VL - 517 IS - 1 SP - 23 EP - 46 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Mulder, Christian A1 - Boit, Alice A1 - Mori, Shigeta A1 - Vonk, J. Arie A1 - Dyer, Scott D. A1 - Faggiano, Leslie A1 - Geisen, Stefan A1 - Gonzalez, Angelica L. A1 - Kaspari, Michael A1 - Lavorel, Sandra A1 - Marquet, Pablo A. A1 - Rossberg, Axel G. A1 - Sterner, Robert W. A1 - Voigt, Winfried A1 - Wall, Diana H. ED - Jacob, U ED - Woodward, G T1 - Distributional (In)Congruence of Biodiversity-Ecosystem Functioning JF - Advances in ecological research JF - Advances in Ecological Research N2 - The majority of research on biodiversity ecosystem functioning in laboratories has concentrated on a few traits, but there is increasing evidence from the field that functional diversity controls ecosystem functioning more often than does species number. Given the importance of traits as predictors of niche complementarity and community structures, we (1) examine how the diversity sensu lato of forest trees, freshwater fishes and soil invertebrates might support ecosystem functioning and (2) discuss the relevance of productive biota for monophyletic assemblages (taxocenes). In terrestrial ecosystems, correlating traits to abiotic factors is complicated by the appropriate choice of body-size distributions. Angiosperm and gymnosperm trees, for example, show metabolic incongruences in their respiration rates despite their pronounced macroecological scaling. Scaling heterotrophic organisms within their monophyletic assemblages seems more difficult than scaling autotrophs: in contrast to the generally observed decline of mass-specific metabolic rates with body mass within metazoans, soil organisms such as protozoans show opposite mass-specific trends. At the community level, the resource demand of metazoans shapes multitrophic interactions. Hence, population densities and their food web relationships reflect functional diversity, but the influence of biodiversity on stability and ecosystem functioning remains less clear. We focused on fishes in 18 riverine food webs, where the ratio of primary versus secondary extinctions (hereafter, 'extinction partitioning') summarizes the responses of fish communities to primary species loss (deletions) and its consequences. Based on extinction partitioning, our high-diversity food webs were just as (or even more) vulnerable to extinctions as low-diversity food webs. Our analysis allows us to assess consequences of the relocation or removal of fish species and to help with decision-making in sustainable river management. The study highlights that the topology of food webs (and not simply taxonomic diversity) plays a greater role in stabilizing the food web and enhancing ecological services than is currently acknowledged. Y1 - 2012 SN - 978-0-12-396992-7 U6 - https://doi.org/10.1016/B978-0-12-396992-7.00001-0 SN - 0065-2504 VL - 46 SP - 1 EP - 88 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Tartivel, Lucile A1 - Behl, Marc A1 - Schröter, Michael A1 - Lendlein, Andreas T1 - Hydrogel networks based on ABA triblock copolymers JF - Journal of applied biomaterials & functional materials N2 - Background: Triblock copolymers from hydrophilic oligo(ethylene glycol) segment A and oligo(propylene glycol) segment B, providing an ABA structure (OEG-OPG-OEG triblock), are known to be biocompatible and are used as self-solidifying gels in drug depots. A complete removal of these depots would be helpful in cases of undesired side effects of a drug, but this remains a challenge as they liquefy below their transition temperature. Therefore we describe the synthesis of covalently cross-linked hydrogel networks. Method: Triblock copolymer-based hydrogels were created by irradiating aqueous solutions of the corresponding macro-dimethacrylates with UV light. The degree of swelling, swelling kinetics, mechanical properties and morphology of the networks were investigated. Results: Depending on precursor concentration, equilibrium degree of swelling of the films ranged between 500% and 880% and was reached in 1 hour. In addition, values for storage and loss moduli of the hydrogel networks were in the 100 Pa to 10 kPa range. Conclusion: Although OEG-OPG-OEG triblocks are known for their micellization, which could hamper polymer network formation, reactive OEG-OPG-OEG triblock oligomers could be successfully polymerized into hydrogel networks. The degree of swelling of these hydrogels depends on their molecular weight and on the oligomer concentration used for hydrogel preparation. In combination with the temperature sensitivity of the ABA triblock copolymers, it is assumed that such hydrogels might be beneficial for future medical applications -e.g., removable drug release systems. KW - Hydrogel KW - Rheological characterization KW - Oligo(ethylene glycol) derivatization KW - OEG-OPG-OEG triblock copolymer KW - UV crosslinking Y1 - 2012 U6 - https://doi.org/10.5301/JABFM.2012.10295 SN - 2280-8000 VL - 10 IS - 3 SP - 243 EP - 248 PB - Wichtig CY - Milano ER - TY - JOUR A1 - Schmidt, Romy A1 - Schippers, Jos H. M. A1 - Welker, Annelie A1 - Mieulet, Delphine A1 - Guiderdoni, Emmanuel A1 - Müller-Röber, Bernd T1 - Transcription factor OsHsfC1b regulates salt tolerance and development in Oryza sativa ssp japonica JF - AoB PLANTS N2 - Background and aims Salt stress leads to attenuated growth and productivity in rice. Transcription factors like heat shock factors (HSFs) represent central regulators of stress adaptation. Heat shock factors of the classes A and B are well established as regulators of thermal and non-thermal stress responses in plants; however, the role of class C HSFs is unknown. Here we characterized the function of the OsHsfC1b (Os01g53220) transcription factor from rice. Methodology We analysed the expression of OsHsfC1b in the rice japonica cultivars Dongjin and Nipponbare exposed to salt stress as well as after mannitol, abscisic acid (ABA) and H2O2 treatment. For functional characterization of OsHsfC1b, we analysed the physiological response of a T-DNA insertion line (hsfc1b) and two artificial micro-RNA (amiRNA) knock-down lines to salt, mannitol and ABA treatment. In addition, we quantified the expression of small Heat Shock Protein (sHSP) genes and those related to signalling and ion homeostasis by quantitative real-time polymerase chain reaction in roots exposed to salt. The subcellular localization of OsHsfC1b protein fused to green fluorescent protein (GFP) was determined in Arabidopsis mesophyll cell protoplasts. Principal results Expression of OsHsfC1b was induced by salt, mannitol and ABA, but not by H2O2. Impaired function of OsHsfC1b in the hsfc1b mutant and the amiRNA lines led to decreased salt and osmotic stress tolerance, increased sensitivity to ABA, and temporal misregulation of salt-responsive genes involved in signalling and ion homeostasis. Furthermore, sHSP genes showed enhanced expression in knock-down plants under salt stress. We observed retarded growth of hsfc1b and knock-down lines in comparison with control plants under non-stress conditions. Transient expression of OsHsfC1b fused to GFP in protoplasts revealed nuclear localization of the transcription factor. Conclusions OsHsfC1b plays a role in ABA-mediated salt stress tolerance in rice. Furthermore, OsHsfC1b is involved in the response to osmotic stress and is required for plant growth under non-stress conditions. Y1 - 2012 U6 - https://doi.org/10.1093/aobpla/pls011 SN - 2041-2851 IS - 3 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Hundertmark, Michaela A1 - Popova, Antoaneta V. A1 - Rausch, Saskia A1 - Seckler, Robert A1 - Hincha, Dirk K. T1 - Influence of drying on the secondary structure of intrinsically disordered and globular proteins JF - Biochemical and biophysical research communications N2 - Circular dichroism (CD) spectroscopy of five Arabidopsis late embryogenesis abundant (LEA) proteins constituting the plant specific families LEA_5 and LEA_6 showed that they are intrinsically disordered in solution and partially fold during drying. Structural predictions were comparable to these results for hydrated LEA_6, but not for LEA_5 proteins. FTIR spectroscopy showed that verbascose, but not sucrose, strongly affected the structure of the dry proteins. The four investigated globular proteins were only mildly affected by drying in the absence, but strongly in the presence of sugars. These data highlight the larger structural flexibility of disordered compared to globular proteins and the impact of sugars on the structure of both disordered and globular proteins during drying. KW - Desiccation KW - CD spectroscopy KW - FTIR spectroscopy KW - Intrinsically disordered proteins KW - LEA proteins KW - Protein secondary structure Y1 - 2012 U6 - https://doi.org/10.1016/j.bbrc.2011.11.067 SN - 0006-291X VL - 417 IS - 1 SP - 122 EP - 128 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Guljamow, Arthur A1 - Delissen, Friedmar A1 - Baumann, Otto A1 - Thuenemann, Andreas F. A1 - Dittmann-Thünemann, Elke T1 - Unique properties of eukaryote-type actin and profilin horizontally transferred to cyanobacteria JF - PLoS one N2 - A eukaryote-type actin and its binding protein profilin encoded on a genomic island in the cyanobacterium Microcystis aeruginosa PCC 7806 co-localize to form a hollow, spherical enclosure occupying a considerable intracellular space as shown by in vivo fluorescence microscopy. Biochemical and biophysical characterization reveals key differences between these proteins and their eukaryotic homologs. Small-angle X-ray scattering shows that the actin assembles into elongated, filamentous polymers which can be visualized microscopically with fluorescent phalloidin. Whereas rabbit actin forms thin cylindrical filaments about 100 mu m in length, cyanobacterial actin polymers resemble a ribbon, arrest polymerization at 510 lam and tend to form irregular multi-strand assemblies. While eukaryotic profilin is a specific actin monomer binding protein, cyanobacterial profilin shows the unprecedented property of decorating actin filaments. Electron micrographs show that cyanobacterial profilin stimulates actin filament bundling and stabilizes their lateral alignment into heteropolymeric sheets from which the observed hollow enclosure may be formed. We hypothesize that adaptation to the confined space of a bacterial cell devoid of binding proteins usually regulating actin polymerization in eukaryotes has driven the co-evolution of cyanobacterial actin and profilin, giving rise to an intracellular entity. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0029926 SN - 1932-6203 VL - 7 IS - 1 SP - 221 EP - 231 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Gruden, Kristina A1 - Hren, Matjaz A1 - Herman, Ana A1 - Blejec, Andrej A1 - Albrecht, Tanja A1 - Selbig, Joachim A1 - Bauer, Christian G. A1 - Schuchardt, Johannes A1 - Or-Guil, Michal A1 - Zupancic, Klemen A1 - Svajger, Urban A1 - Stabuc, Borut A1 - Ihan, Alojz A1 - Kopitar, Andreja Natasa A1 - Ravnikar, Maja A1 - Knezevic, Miomir A1 - Rozman, Primoz A1 - Jeras, Matjaz T1 - A "Crossomics" study analysing variability of different components in peripheral blood of healthy caucasoid individuals JF - PLoS one N2 - Background: Different immunotherapy approaches for the treatment of cancer and autoimmune diseases are being developed and tested in clinical studies worldwide. Their resulting complex experimental data should be properly evaluated, therefore reliable normal healthy control baseline values are indispensable. Methodology/Principal Findings: To assess intra- and inter-individual variability of various biomarkers, peripheral blood of 16 age and gender equilibrated healthy volunteers was sampled on 3 different days within a period of one month. Complex "crossomics'' analyses of plasma metabolite profiles, antibody concentrations and lymphocyte subset counts as well as whole genome expression profiling in CD4(+)T and NK cells were performed. Some of the observed age, gender and BMI dependences are in agreement with the existing knowledge, like negative correlation between sex hormone levels and age or BMI related increase in lipids and soluble sugars. Thus we can assume that the distribution of all 39.743 analysed markers is well representing the normal Caucasoid population. All lymphocyte subsets, 20% of metabolites and less than 10% of genes, were identified as highly variable in our dataset. Conclusions/Significance: Our study shows that the intra- individual variability was at least two-fold lower compared to the inter-individual one at all investigated levels, showing the importance of personalised medicine approach from yet another perspective. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0028761 SN - 1932-6203 VL - 7 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Hinz, Justyna A1 - Lehnhardt, Lothar A1 - Zakrzewski, Silke A1 - Zhang, Gong A1 - Ignatova, Zoya T1 - Polyglutamine expansion alters the dynamics and molecular architecture of aggregates in dentatorubropallidoluysian atrophy JF - The journal of biological chemistry N2 - Preferential accumulation of mutant proteins in the nucleus has been suggested to be the molecular culprit that confers cellular toxicity in the neurodegenerative disorders caused by polyglutamine (polyQ) expansion. Here, we use dynamic imaging approaches, orthogonal cross-seeding, and composition analysis to examine the dynamics and structure of nuclear and cytoplasmic inclusions of atrophin-1, implicated in dentatorubropallidoluysian atrophy, a polyQ-based disease with complex clinical features. Our results reveal a large heterogeneity in the dynamics of the nuclear inclusions compared with the compact and immobile cytoplasmic aggregates. At least two types of inclusions of expanded atrophin-1 with different mobility of the molecular species and ability to exchange with the surrounding monomer pool coexist in the nucleus. Intriguingly, the enrichment of nuclear inclusions with slow dynamics parallels changes in the aggregate core architecture that are dominated by the polyQ stretch. We propose that the observed complexity in the dynamics of the nuclear inclusions provides a molecular explanation for the enhanced cellular toxicity of the nuclear aggregates in polyQ-based neurodegeneration. Y1 - 2012 U6 - https://doi.org/10.1074/jbc.M111.318915 SN - 0021-9258 VL - 287 IS - 3 SP - 2068 EP - 2078 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda ER - TY - JOUR A1 - Krüger, Anne A1 - Batsios, Petros A1 - Baumann, Otto A1 - Luckert, Eva A1 - Schwarz, Heinz A1 - Stick, Reimer A1 - Meyer, Irene A1 - Gräf, Ralph T1 - Characterization of NE81, the first lamin-like nucleoskeleton protein in a unicellular organism JF - Molecular biology of the cell : the official publication of the American Society for Cell Biology N2 - Lamins build the nuclear lamina and are required for chromatin organization, gene expression, cell cycle progression, and mechanical stabilization. Despite these universal functions, lamins have so far been found only in metazoans. We have identified protein NE81 in Dictyostelium, which has properties that justify its denomination as a lamin-like protein in a lower eukaryote. This is based on its primary structure, subcellular localization, and regulation during mitosis, and its requirement of the C-terminal CaaX box as a posttranslational processing signal for proper localization. Our knockout and overexpression mutants revealed an important role for NE81 in nuclear integrity, chromatin organization, and mechanical stability of cells. All our results are in agreement with a role for NE81 in formation of a nuclear lamina. This function is corroborated by localization of Dictyostelium NE81 at the nuclear envelope in human cells. The discovery of a lamin-like protein in a unicellular organism is not only intriguing in light of evolution, it may also provide a simple experimental platform for studies of the molecular basis of laminopathies. Y1 - 2012 U6 - https://doi.org/10.1091/mbc.E11-07-0595 SN - 1059-1524 VL - 23 IS - 2 SP - 360 EP - 370 PB - American Society for Cell Biology CY - Bethesda ER - TY - INPR A1 - Lenhard, Michael T1 - All's well that ends well arresting cell proliferation in leaves T2 - Developmental cell N2 - The transition from cell proliferation to cell expansion is critical for determining leaf size. Andriankaja et al. (2012) demonstrate that in leaves of dicotyledonous plants, a basal proliferation zone is maintained for several days before abruptly disappearing, and that chloroplast differentiation is required to trigger the onset of cell expansion. Y1 - 2012 U6 - https://doi.org/10.1016/j.devcel.2011.12.004 SN - 1534-5807 VL - 22 IS - 1 SP - 9 EP - 11 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Hartmann, Stefanie A1 - Helm, Conrad A1 - Nickel, Birgit A1 - Meyer, Matthias A1 - Struck, Torsten H. A1 - Tiedemann, Ralph A1 - Selbig, Joachim A1 - Bleidorn, Christoph T1 - Exploiting gene families for phylogenomic analysis of myzostomid transcriptome data JF - PLoS one N2 - Background: In trying to understand the evolutionary relationships of organisms, the current flood of sequence data offers great opportunities, but also reveals new challenges with regard to data quality, the selection of data for subsequent analysis, and the automation of steps that were once done manually for single-gene analyses. Even though genome or transcriptome data is available for representatives of most bilaterian phyla, some enigmatic taxa still have an uncertain position in the animal tree of life. This is especially true for myzostomids, a group of symbiotic ( or parasitic) protostomes that are either placed with annelids or flatworms. Methodology: Based on similarity criteria, Illumina-based transcriptome sequences of one myzostomid were compared to protein sequences of one additional myzostomid and 29 reference metazoa and clustered into gene families. These families were then used to investigate the phylogenetic position of Myzostomida using different approaches: Alignments of 989 sequence families were concatenated, and the resulting superalignment was analyzed under a Maximum Likelihood criterion. We also used all 1,878 gene trees with at least one myzostomid sequence for a supertree approach: the individual gene trees were computed and then reconciled into a species tree using gene tree parsimony. Conclusions: Superalignments require strictly orthologous genes, and both the gene selection and the widely varying amount of data available for different taxa in our dataset may cause anomalous placements and low bootstrap support. In contrast, gene tree parsimony is designed to accommodate multilocus gene families and therefore allows a much more comprehensive data set to be analyzed. Results of this supertree approach showed a well-resolved phylogeny, in which myzostomids were part of the annelid radiation, and major bilaterian taxa were found to be monophyletic. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0029843 SN - 1932-6203 VL - 7 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Blumroeder, J. A1 - Eccard, Jana A1 - Blaum, Niels T1 - Behavioural flexibility in foraging mode of the spotted sand lizard (Pedioplanis l. lineoocellata) seems to buffer negative impacts of savanna degradation JF - Journal of arid environments N2 - In this field experiment we investigate the impact of land use induced savanna degradation on movement behaviour of the spotted sand lizard (Pedioplanis l. lineoocellata) in the southern Kalahari. Foraging behaviour of lizards was tested in a factorial design (low vs. high prey availability) in degraded and non-degraded habitats. An interaction between habitat structure and prey availability affected movement behaviour. In degraded habitats with low prey availability and in non-degraded habitats with high prey availability the spotted sand lizard moved more like an active forager. In contrast, in degraded habitats with high prey availability and in non-degraded habitats with low prey availability lizards moved like sit-and-wait foragers. Interestingly, the behavioural flexibility of the spotted sand lizard seems to buffer extreme conditions and negative effects of land use impacts. KW - Kalahari KW - Land use KW - Movement ecology KW - Overgrazing KW - Shrub encroachment Y1 - 2012 U6 - https://doi.org/10.1016/j.jaridenv.2011.10.005 SN - 0140-1963 VL - 77 IS - 2 SP - 149 EP - 152 PB - Elsevier CY - London ER -