TY - JOUR A1 - Walz, Bernd T1 - Überlebenskünstler aus dem Moospolster N2 - Populärwissenschaftlicher Aufsat Y1 - 1997 ER - TY - BOOK A1 - Wartenberg, Maria T1 - Über Nutzen und Grenzen der Stammzellenforschung : Antrittsvorlesung 2006-07-06 N2 - Die Referentin erläutert den Ursprung embryonaler Stammzellen und woher sie kommen. Gezeigt wird weiter unter anderem die Gewinnung embryonaler Stammzellen aus der Blastozyste der Maus, und es wird auf die Differenzierung von glatter Muskulatur und Knochen eingegangen. Die Wissenschaftlerin sieht in der Etablierung neuer in vitro Modelle eine große Perspektive für die Forschung mit Maus-Stammzellen. Y1 - 2006 UR - http://info.ub.uni-potsdam.de/multimedia/show_projekt.php?projekt_id=12 PB - Univ.-Bibl. CY - Potsdam ER - TY - THES A1 - Schorling, Markus T1 - Ökologische und phytomedizinische Untersuchungen zum Anbau von Bt-Mais im Maiszünsler-Befallsgebiet Oderbruch T1 - Ecological and phytomedical investigations on Bt maize grown in the European corn borer (Ostrinia nubilalis) infested area in the Oderbruch region (Germany) N2 - In den letzten 20 Jahren hat sich der Maiszünsler (Ostrinia nubilalis HÜBNER), aus der Schmetterlingsfamilie der Pyralidae oder Zünsler, zum bedeutendsten tierischen Schädling des Maises (Zea mays) entwickelt. Eine Möglichkeit den Befall des Maiszünslers abzuwenden, bietet der Anbau von Bacillus thuringiensis-Mais (Bt-Mais). Mit Hilfe der Gentechnik wurden Gene des Bakteriums Bacillus thuringiensis übertragen, die einen für Fraßinsekten giftigen Wirkstoff bilden, wodurch die Pflanzen während der kompletten Vegetation vor den Larven des Maiszünslers geschützt sind. Ziel des vorliegenden Projektes war es, in einer 3-jährigen Studie die Auswirkungen des großflächigen Anbaus von Bt-Mais auf die ökologische Situation und den Handlungsrahmen des integrierten Pflanzenschutzes komplex zu untersuchen. Dazu wurden in Betrieben im Oderbruch, das als permanentes Befallsgebiet des Maiszünslers gilt, in den Jahren 2002 bis 2004 jährlich zwei Felder mit jeweils einer Bt-Sorte und einer konventionellen Sorte angelegt. Zusätzlich wurden biologische und chemische Maiszünsler-Bekämpfungsvarianten geprüft. Durch verschiedene Methoden wie Bonituren, Ganzpflanzenernten, Bodenfallenfänge und Beobachtungen des Wahlverhaltens von (Flug-)insekten konnten Aussagen zum Vorkommen von Insekten und Spinnentieren getroffen werden, wobei hierfür Daten aus Untersuchungen der Jahre 2000 und 2001 im Oderbruch ergänzend herangezogen werden konnten. Durch Ertragsmessungen, Energie- und Qualitätsermittlungen, sowie Fusarium- und Mykotoxinanalysen konnte der Anbau von Bt-Mais als neue Alternative zur Bekämpfung des Maiszünslers bewertet werden. Bezüglich des Auftretens von Insekten und Spinnentieren wurden im Mittel der fünfjährigen Datenerhebung beim Vergleich der Bt-Sorte zur konventionellen Sorte, mit Ausnahme der fast 100 %igen Bekämpfung des Maiszünslers, keine signifikanten Unterschiede festgestellt. Hierfür wurde ein besonderes Augenmerk auf Thripse, Wanzen, Blattläuse und deren Fraßfeinde, sowie mittels Bodenfallenfängen auf Laufkäfer und Spinnen gerichtet. Die erwarteten ökonomischen Vorteile wie etwa Ertragsplus oder bessere Nährstoff- und Energiegehalte durch geringeren Schaden beim Anbau von Bt-Mais als Silomais blieben in den Untersuchungsjahren aus. Allerdings zeigten Fusarium- und Mykotoxinanalysen eine geringere Belastung des Bt-Maises, was möglicherweise auf den geringeren Schaden zurückzuführen ist, da beschädigte Pflanzen für Fusarium und Mykotoxine anfälliger sind. Desweiteren konnten erste methodische Ansätze für ein auf EU-Ebene gefordertes, den Anbau von Bt-Mais begleitendes Monitoring, erarbeitet werden. So konnten Vorschläge für geeignete Methoden, deren Umfang sowie des Zeitpunktes der Durchführungen gemacht werden. N2 - In the last 20 years the European corn borer (Ostrinia nubilalis, Pyralidae) has become the most important pest in maize (Zea mays). One of a couple of possibilities to reduce the infestation by the European corn borer is the cultivation of Bacillus thuringiensis maize (Bt maize). Genetic engineering transmitted genes from Bacillus thuringiensis, which produce a substance that is toxic to feeding insects and thus protect plants against the larvae of the European corn borer during the whole vegetation. The present project is a 3-year study to identify the effects of Bt maize growing on the ecological situation and the possibilities of integrated plant protection. From 2002 to 2004, two fields in the Oderbruch region, where Ostrinia nubilalis occurs, were each planted with Bt maize and a conventional maize variety every year. Furthermore, a biological and a chemical strategy against the European corn borer were verified. Different methods like counts, harvest of whole plants, pitfall traps and observation the landing behaviour of flying insects were used to determine the abundance of insects and spiders. Furthermore, we could use additional data from studies obtained in the Oderbruch region in 2000 and 2001. The determination of yield, quality and energy content of the crops as well as of the degree of Fusarium infection and contamination by mycotoxins led to the conclusion that the cultivation of Bt maize is a new alternative strategy to control the European corn borer. The average occurrence of insects and spiders did not differ significantly between Bt maize and the conventional variety in the 5 years of data recording. The only exception is the almost total control of the European corn borer. Attention was especially paid to thrips, bugs, aphids and their feeding enemies and using ground traps to ground beetles and spiders. The expected economic benefits like increased yield or nutrient and energy content of the crop as a result of a minimized damage to silage Bt maize were not achieved in the years under investigation. However, the analysis of Fusarium and mycotoxins indicated a lower exposure of Bt maize, which may result from a lower damage caused by Ostrinia nubilalis, and damaged plants are more susceptible to Fusarium and mycotoxins. Furthermore, we developed a first methodological approach for the monitoring procedure of Bt maize growing required by the EU. We have made proposals on appropriate methods, their extent as well as the optimum time of their application. KW - Maiszünsler KW - Oderbruch KW - Monitoring KW - Gentechnologie KW - Biodiversität KW - Bt-Mais KW - Bt maize KW - European corn borer KW - Ostrinia nubilalis KW - genetic engineering KW - monitoring Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-6260 ER - TY - JOUR A1 - Jeltsch, Florian T1 - Ökologische Forschungen an der Unteren Havel BT - ein Ausblick JF - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-4100 SN - 1434-2375 SN - 1611-9339 VL - 13 SP - 138 EP - 139 ER - TY - JOUR A1 - Wallschläger, Hans-Dieter A1 - Beier, Wolfgang A1 - Burkart, Michael A1 - Mrzljak, Jadranka A1 - Oehlschläger, Susanne A1 - Wanner, Manfred T1 - Ökologische Datenerfassung für Naturschutzbewertung und Monitoring im Offenland Y1 - 2004 SN - 3-540-22449-1 ER - TY - JOUR A1 - Beier, Wolfgang A1 - Hinrichsen, A. A1 - Klatt, Reimund T1 - Ökofaunistische Untersuchungen auf ausgewählten Truppenübungsplätzen Brandenburgs BT - Laufkäfer (Carabidae), räuberische und parasitoide Wespen (Hymenoptera), Heuschrecken (Saltatoria) JF - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-2788 SN - 1434-2375 SN - 1611-9339 VL - 1 SP - 130 EP - 137 ER - TY - JOUR A1 - Kummer, Volker T1 - Zusammenstellung lokaler Pilzliteratur 2004 - 2008 Y1 - 2010 SN - 0232-4598 ER - TY - JOUR A1 - Kummer, Volker T1 - Zusammenstellung lokaler Pilzliteratur 2000 - 2003 Y1 - 2005 ER - TY - JOUR A1 - Kummer, Volker T1 - Zur Wasserpflanzenvegetation des Neuendorfer Sees Y1 - 1996 ER - TY - JOUR A1 - Fischer, Wolfgang A1 - Kummer, Volker T1 - Zur Verbreitung und Soziologie von S colochloa festucacea L : in Nordostdeutschland und seine Unterscheidung von ähnlichen Gräsern nach vegetativen Merkmalen Y1 - 1994 ER - TY - JOUR A1 - Seitz, Birgit A1 - Ristow, Michael A1 - Klemm, Gunther A1 - Rätzel, Stefan A1 - Schulze, Gerhart A1 - Hoffmann, Maik T1 - Zur Verbreitung der Wildrosen und verwilderten Kulturrosen in Berlin und Brandenburg Y1 - 2004 SN - 0724-3111 - ER - TY - JOUR A1 - Fischer, Wolfgang A1 - Kummer, Volker A1 - Pötsch, Joachim T1 - Zur Vegetation des Feuchtgebietes Internationaler Bedeutung (FIB) Untere Havel Y1 - 1994 ER - TY - JOUR A1 - Knösche, Rüdiger A1 - Bukowsky, Heinz T1 - Zur Schwermetallakkumulation in Dactylis glomerata auf Rieselfeldböden Y1 - 1996 SN - 3-7983-1680-5 ER - TY - JOUR A1 - Kummer, Volker T1 - Zur Pilzflora des Kienbergs bei Wolsier mit Hinweisen auf die Phanerogamenflora Y1 - 1996 ER - TY - JOUR A1 - Knösche, Ralf T1 - Zur Phospatrücklösung aus Augewässersedimenten unter veränderter Hochwasserdynamik JF - Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-4077 SN - 1434-2375 SN - 1611-9339 VL - 13 SP - 102 EP - 113 ER - TY - JOUR A1 - Baumann, Guido A1 - Eckermann, Nora A1 - Meinel, Thomas T1 - Zur Kohlenstoffassimilation in grünen Zuckerrüben-Kalluskulturen Y1 - 1994 ER - TY - JOUR A1 - Ristow, Michael A1 - Seitz, Birgit T1 - Zur Kenntnis einiger übersehener, wenig beachteter oder verkannter Sippen der Gattungen Vicia und Valerianella in Brandenburg Y1 - 2002 ER - TY - THES A1 - Oehlschläger, Susanne T1 - Zur Habitatwahl, Nahrungsökologie und Brutbiologie des Wiederhopfes (Upupa epops) Linné 1958 auf den ehemaliegen Truppenübungsplätzen bei Jüterbog, Brandenburg Y1 - 2001 ER - TY - JOUR A1 - Scheffler, Ingo T1 - Zur Fähigkeit von Ektoparasiten der Fledermäuse ihre Wirte aktiv aufzusuchen N2 - Active host-searching in bat ectoparasites. As a pilot study, this paper discribes the mobility of ectoparasites after removing from their hosts. Spinturnix acuminatus (Koch, 1836)(Acari, Spinturnicidae) a permanent stationary bat mite normally survives the removing only a few hours. This species moves easily on the patagium or on human skin. In contrast, on other surfaces the movements of this species seems to be less orientated and it is unlikely that the mite can reach a host in some distance. Nycteribia kolenatii Theodor & Moscona, 1954 (Diptera: Nycteribiidae) a bat fly, shows excellent movements in the fur of its host. The specimens survive the removing from the host several days. The ability to clamber up a wall was tested with a rough clay brick. The bat fly achieves only 9,6 cm on average. This result does not support good abilities for host searching in this species. Bat fleas (Siphonaptera: Ischnopsyllidae): Ischnopsyllus elongatus (Curtis, 1832), I. hexactenus (Kolenati, 1856), I. simplex (Rothschild, 1906)and other species survive the removing from their hosts several days. In case of a vertical barrier they showed a stereotype upside climbing, followed by a horizontal appetitive behavior. The fleas were climbing a distance in the upside of 6,45 m on average(1,2-21,68 m). As excellent climbers bat fleas are able to overcome edges and slopes and to crawl on the ceiling. Therefore, it seems to be no problem for a flea to parasite any bat in a resting room. Additionally, some bugs (Cimex lectularius Linnaeus, 1758) were examinated. They run with a speed of 63 cm per minute and were able to climb easily on the brick. On average their stretch of way achieved 2,85 m in ten minutes. Y1 - 2008 ER - TY - JOUR A1 - Gläser, Hans-Joachim A1 - Schönfelder, J. T1 - Zur Faunistik, Biologie und Ökologie der Wasserflöhe (Crustacea, Cladocera) der Havelaue - ein Beitrag für einen ökosystemaren Restaurationsansatz Y1 - 1994 ER - TY - JOUR A1 - Bergstedt, Christel T1 - Zur Erarbeitung von Aufgabenstellungen im Fach Biologie auf der Grundlage des Rahmenplans Y1 - 1999 ER - TY - JOUR A1 - Lindecke, Oliver A1 - Scheffler, Ingo T1 - Zur Ektoparasitenfauna der Fledermäuse in Sachsen Anhalt : Ectoparasites of bats in Saxony-Anhalt N2 - During the summer 2010 several mist nettings for the monitoring of bat species were performed in Saxony-Anhalt. Captured individuals were tested for ectoparasitic infestation. The aim was to update the fauna of ectoparasites of this state and to collect data on the distribution of individual species. Regarding this, results of previous surveys are summarised. In the present study nine out of thirteen bat species were found to be infested with a total of one flea species, one species of bat flies and eight species of mites. The infestation with fleas was below the expectations. Six spinturnicid mite species out of those occurring in Germany could be ascertained for Saxony-Anhalt. These are Spinturnix acuminatus (Koch, 1836), S. andegavinus (Kolenati, 1857), S. helvetiae Deunff, Keller & Aellen, 1986, S. mystacinus (Kolenati, 1857), S. plecotinus (Koch, 1839) and S. puncata (Sundevall, 1833). Details about the infestation with parasites (abundances) of the respective bat species are presented. Further information on the biology of spinturnicid mites are given and infestation characteristics are compared with those of other surveys. Keywords: ectoparasites, bats, Chiroptera, gamasine mite, Acari, Spinturnix, Ischnopsyllidae, Nycteribiidae, Saxony-Anhalt, Germany Y1 - 2011 SN - 0018-0637 ER - TY - JOUR A1 - Scheffler, Ingo A1 - Hiller, Andre T1 - Zur Ektoparasitenfauna der Fledermäuse in Niedersachsen : Neue Funde am Iberg bei Bad Grund N2 - Bei einer aktuellen Studie am Iberg in Bad Grund konnten im September 2010 acht Fledermausarten parasitologisch untersucht werden. Die Faenge ergaben Nachweise von 11 Ektoparasitenarten (Fledermausfliegen, Floehe, Flughaut- und Ohrmilben), wobei einige davon Erstfunde fuer Niedersachsen sind. Aus den Fundangaben wurden Parasitenspektren fuer die einzelnen Wirtsarten erstellt und durch weitere unveroeffentlichte Meldungen ergaenzt. Fuer den Vergleich von Ektoparasitenspektren verschiedener Wirtsarten erfolgte die Einfuehrung einer Formel, die die Berechnung einer allgemeinen "Parasitenlast" ermoeglicht. Die Betrachtung der Verteilung von Ektoparasiten auf Individuen zeigte eine starke Trennung verschiedener Parasitengruppen, ein synchrones Vorkommen wurde nur selten registriert. Moeglicherweise ist die Konkurrenz zwischen Ektoparasitenarten ein bisher unterschaetzter determinierender Faktor fuer die Praesenz auf einem Wirt. Y1 - 2010 ER - TY - JOUR A1 - Fischer, Petra A1 - Heinken, Thilo A1 - Meyer, Peter A1 - Schmidt, Marcus A1 - Waesch, Gunnar T1 - Zur Abgrenzung und Situation des FFH-Lebensraumtyps "Mitteleuropäische Flechten-Kiefernwälder" (91TO) in Deutschland N2 - Die in Deutschland gegenwärtig durch Nährstoffeinträge und ausbleibenden Nährstoffentzug stark im Rückgang begriffenen Flechten-Kiefernwälder werden als Biotoptyp wie auch als Lebensraumtyp "Mitteleuropäische Flechten-Kiefernwälder" (Code 91T0) diskutiert. Die bisherige, sehr uneinheitliche Differenzierung von Flechten-Kiefernwäldern auf der Ebene von Biotoptypen wird dargestellt. Auf der Grundlage neuerer vegetationskundlicher übersichten werden Vorschläge für eine einheitliche Abgrenzung des Biotoptyps "Flechten-Kiefernwald" und des Lebensraumtyps 91T0 unterbreitet. Im niedersächsischen Naturwaldreservat "Kaarßer Sandberge" (Niedersachsen) wurde die Anwendung des Konzeptes erfolgreich erprobt. Nicht nur hier, sondern auch deutschlandweit wird der Rückgang der Erdflechten in den Kieferwäldern zugunsten von Drahtschmiele und/ oder pleurokarpen Moosen deutlich. Nach der derzeitigen Definition des Lebensraumtyps 91T0 besteht auf der Grundlage der FFH-Richtlinie nicht für alle Flechten-Kiefernwälder eine Chance der Verbesserung. Der Ausschluss von außerhalb des natürlichen Verbreitungsgebietes der Wald-Kiefer gelegenen sowie von durch Aufforstung angepflanzten Beständen bringt Probleme mit sich, die diskutiert werden. Für den Erhalt und die Wiederherstellung der größtenteils nutzungsbedingt entstandenen Flechten-Kiefernwälder sind praktikable Pflegemaßnahmen notwendig, die im Rahmen von Streunutzungsversuchen erprobt werden müssen. Y1 - 2009 SN - 0028-0615 ER - TY - BOOK A1 - Siering, Günter A1 - Beier, Wolfgang T1 - Zum Vorkommen von Bockkäfern (Col., Cerambicidae) im Gebiet des ehemaligen GUS-Truppenübungsplatzes "Dallgow-Döberitz" bei Potsdam, 1. Nachtrag Y1 - 2001 ER - TY - JOUR A1 - Kummer, Volker T1 - Zum Vorkommen von Asplenium viride HUDS : in Berlin und Brandenburg Y1 - 1996 ER - TY - JOUR A1 - Kummer, Volker T1 - Zum Vorkommen im Cetraria islandica (.L) ACH., dem isländischen Moos, und Cetraria ericetorium OPIZ in Brandenburg unter besonderer Berücksichtigung der Niederlausitz Y1 - 1998 ER - TY - JOUR A1 - Kummer, Volker T1 - Zum Vorkommen des Sternstäublings (Mycenastrum corium) in der Niederlausitz Y1 - 1993 ER - TY - JOUR A1 - Ristow, Michael A1 - Burkart, Michael A1 - Prasse, Rüdiger T1 - Zum Vorkommen der Bleichen Hainsimse, Luzula pallidula Kirschner (syn. L. pallescens auct.) in Brandenburg Y1 - 1997 ER - TY - THES A1 - Otto, Sebastian T1 - Zulassungskonforme und schnelle massenspektronomische Analytik und präklinische Pharmakokinetik neuer Wirkstoffkandidaten Y1 - 2013 CY - Potsdam ER - TY - JOUR A1 - Tang, Kam W. A1 - Gladyshev, Michail I. A1 - Dubovskaya, Olgo P. A1 - Kirillin, Georgiy A1 - Grossart, Hans-Peter T1 - Zooplankton carcasses and non-predatory mortality in freshwater and inland sea environments JF - Journal of plankton research N2 - Zooplankton carcasses are ubiquitous in marine and freshwater systems, implicating the importance of non-predatory mortality, but both are often overlooked in ecological studies compared with predatory mortality. The development of several microscopic methods allows the distinction between live and dead zooplankton in field samples, and the reported percentages of dead zooplankton average 11.6 (minimum) to 59.8 (maximum) in marine environments, and 7.4 (minimum) to 47.6 (maximum) in fresh and inland waters. Common causes of non-predatory mortality among zooplankton include senescence, temperature change, physical and chemical stresses, parasitism and food-related factors. Carcasses resulting from non-predatory mortality may undergo decomposition leading to an increase in microbial production and a shift in microbial composition in the water column. Alternatively, sinking carcasses may contribute significantly to vertical carbon flux especially outside the phytoplankton growth seasons, and become a food source for the benthos. Global climate change is already altering freshwater ecosystems on multiple levels, and likely will have significant positive or negative effects on zooplankton non-predatory mortality. Better spatial and temporal studies of zooplankton carcasses and non-predatory mortality rates will improve our understanding of this important but under-appreciated topic. KW - carbon flux KW - inland waters KW - lakes KW - live KW - dead sorting KW - non-predatory mortality KW - zooplankton carcasses Y1 - 2014 U6 - https://doi.org/10.1093/plankt/fbu014 SN - 0142-7873 SN - 1464-3774 VL - 36 IS - 3 SP - 597 EP - 612 PB - Oxford Univ. Press CY - Oxford ER - TY - THES A1 - Kiemel, Katrin T1 - Zooplankton adaptations and community dynamics in space and time N2 - In times of ongoing biodiversity loss, understanding how communities are structured and what mechanisms and local adaptations underlie the patterns we observe in nature is crucial for predicting how future ecological and anthropogenic changes might affect local and regional biodiversity. Aquatic zooplankton are a group of primary consumers that represent a critical link in the food chain, providing nutrients for the entire food web. Thus, understanding the adaptability and structure of zooplankton communities is essential. In this work, the genetic basis for the different temperature adaptations of two seasonally shifted (i.e., temperature-dependent) occurring freshwater rotifers of a formerly cryptic species complex (Brachionus calyciflorus) was investigated to understand the overall genetic diversity and evolutionary scenario for putative adaptations to different temperature regimes. Furthermore, this work aimed to clarify to what extent the different temperature adaptations may represent a niche partitioning process thus enabling co-existence. The findings were then embedded in a metacommunity context to understand how zooplankton communities assemble in a kettle hole metacommunity located in the northeastern German "Uckermark" and which underlying processes contribute to the biodiversity patterns we observe. Using a combined approach of newly generated mitochondrial resources (genomes/cds) and the analysis of a candidate gene (Heat Shock Protein 40kDa) for temperature adaptation, I showed that the global representatives of B. calyciflorus s.s.. are genetically more similar than B. fernandoi (average pairwise nucleotide diversity: 0.079 intraspecific vs. 0.257 interspecific) indicating that both species carry different standing genetic variation. In addition to differential expression in the thermotolerant B. calyciflorus s.s. and thermosensitive B. fernandoi, the HSP 40kDa also showed structural variation with eleven fixed and six positively selected sites, some of which are located in functional areas of the protein. The estimated divergence time of ~ 25-29 Myr combined with the fixed sites and a prevalence of ancestral amino acids in B. calyciflorus s.s. indicate that B. calyciflorus s.s. remained in the ancestral niche, while B. fernandoi partitioned into a new niche. The comparison of mitochondrial and nuclear markers (HPS 40kDa, ITS1, COI) revealed a hybridisation event between the two species. However, as hybridisation between the two species is rare, it can be concluded that the temporally isolated niches (i.e., seasonal-shifted occurrence) they inhabit based on their different temperature preferences most likely represent a pre-zygotic isolation mechanism that allows sympatric occurrence while maintaining species boundaries. To determine the processes underlying zooplankton community assembly, a zooplankton metacommunity comprising 24 kettle holes was sampled over a two-year period. Active (i.e., water samples) and dormant communities (i.e., dormant eggs hatched from sediment) were identified using a two-fragment DNA metabarcoding approach (COI and 18S). Species richness and diversity as well as community composition were analysed considering spatial, temporal and environmental parameters. The analysis revealed that environmental filtering based on parameters such as pH, size and location of the habitat patch (i.e., kettle hole) and surrounding field crops largely determined zooplankton community composition (explained variance: Bray-Curtis dissimilarities: 10.5%; Jaccard dissimilarities: 12.9%), indicating that adaptation to a particular habitat is a key feature of zooplankton species in this system. While the spatial configuration of the kettle holes played a minor role (explained variance: Bray-Curtis dissimilarities: 2.8% and Jaccard dissimilarities: 5.5%), the individual kettle hole sites had a significant influence on the community composition. This suggests monopolisation/priority effects (i.e., dormant communities) of certain species in individual kettle holes. As environmental filtering is the dominating process structuring zooplankton communities, this system could be significantly influenced by future land-use change, pollution and climate change. N2 - In Zeiten des fortschreitenden Verlusts biologischer Vielfalt ist es von entscheidender Bedeutung zu verstehen, wie natürliche Gemeinschaften strukturiert sind und welche Mechanismen und lokalen Anpassungen den beobachteten Biodiversitätsmustern zugrunde liegen, um eine wissenschaftliche Grundlage für die Vorhersage künftiger Veränderungen der lokalen und regionalen biologische Vielfalt zu schaffen. Aquatisches Zooplankton ist eine artenreiche Gruppe Primärkonsumenten, die ein entscheidendes Glied in der Nahrungskette darstellen, indem sie Nährstoffe für das gesamte Nahrungsnetz bereitstellen. Daher ist es von entscheidender Bedeutung, die Anpassungsfähigkeit und Struktur von Zooplanktongemeinschaften zu verstehen. In dieser Arbeit wurden die genetischen Grundlagen für die unterschiedliche Temperaturanpassung zweier saisonal-versetzt (d.h. temperaturabhängig) vorkommender limnischen Rädertierarten eines ehemals kryptischen Artenkomplexes (Brachionus calyciflorus) untersucht, um die genetische Variation und das evolutionäre Divergenz-Szenario sowie Grundlagen für die mutmaßliche Anpassungen an unterschiedliche Temperaturregime zu verstehen. Weiterhin sollte untersucht werden, ob die Temperaturanpassungen als Prozess der Nischenaufteilung verstanden werden können die die Koexistenz der Arten ermöglicht. Diese Ergebnisse wurden dann in einen Metagemeinschaftskontext eingebettet, um zu verstehen, wie sich Zooplanktongemeinschaften in einer Soll-Metagemeinschaft, welche sich in der nordostdeutschen Region "Uckermark" befindet, zusammensetzen und welche zugrundeliegenden Prozesse zu den beobachteten Biodiversitätsmustern führen. Eine Kombination aus neu generierten mitochondrialen Ressourcen (Genome/codierende Sequenzen) und der Analyse eines Kandidatengens (HSP 40kDa Gen) für die Temperaturanpassung ergab zum einen, dass die globalen Vertreter von B. calyciflorus s.s. einander genetisch ähnlicher sind als B. fernandoi (Nukleotiddiversität: 0,079 intraspezifisch vs. 0,257 interspezifisch) und beide Arten somit eine unterschiedliche genetische Variation besitzen. Zum anderen wird das HSP 40kDa wird nicht nur in dem wärmetoleranten B. calyciflorus s.s. und wärmeempfindlichen B. fernandoi unterschiedlich exprimiert, sondern weist auch strukturelle Variationen mit elf fixierten und sechs positiv selektierten Positionen auf, von denen einige in funktionellen Regionen des HSP 40kDa liegen. Die geschätzte Divergenzzeit von ca. 25-29 Millionen Jahren sowie die fixierten Positionen und die Dominanz anzestraler Aminosäuren in B. calyciflorus s.s. legen nahe, dass B. calyciflorus s.s. in der anzestralen Nische verblieb, während B. fernandoi eine neue Nische besetzte. Der Vergleich von mitochondrialen und nukleären Markern (HSP 40kDa, ITS1, COI) ergab ein Hybridisierungsereignis zwischen beiden Arten. Da Hybridisierung jedoch selten ist, können die zeitlich isolierten Nischen (d.h. saisonal-versetztes Auftreten), die sie aufgrund ihrer unterschiedlichen Temperaturpräferenzen bewohnen, als prä-zygotischer Isolationsmechanismus verstanden werden, der ein sympatrisches Vorkommen der Arten unter Aufrechterhaltung der Artgrenzen ermöglicht. Um die Prozesse zu bestimmen, die der Strukturierung von Zooplanktongemeinschaften zugrunde liegen, wurde über einen Zeitraum von zwei Jahren eine Zooplankton-Metagemeinschaft, bestehend aus 24 Söllen beprobt. Aktive (d.h. Wasserproben) und ruhende Gemeinschaften (d.h. aus dem Sediment geschlüpfte Gemeinschaften) wurden mit einem Zwei-Fragment-DNA-Metabarcoding-Ansatz (COI und 18S) bestimmt. Die Artenzahl und Abundanz sowie die Zusammensetzung der Gemeinschaften wurden unter Berücksichtigung räumlicher, zeitlicher und umweltbezogener Parameter analysiert. Die Analyse ergab, dass Umweltfilterung basierend auf Parametern wie pH-Wert, Größe, Lage und Typ des Habitats (d.h. des Solls) und der umgebenden Feldfrüchte die Zusammensetzung der Zooplanktongemeinschaft weitgehend bestimmt (erklärte Varianz: Bray-Curtis-Dissimilaritäten: 10,5%; Jaccard-Dissimilaritäten: 12,9%), was darauf hindeutet, dass die Anpassung an einen bestimmten Lebensraum ein wichtiges Merkmal der Zooplanktonarten in diesem System ist. Während die räumliche Struktur der Sölle eine geringe Rolle spielte (erklärte Varianz: Bray-Curtis-Dissimilaritäten: 2,8% und Jaccard-Dissimilaritäten: 5,5%), hatten die einzelnen Standorte einen erheblichen Einfluss auf die Zusammensetzung der Gemeinschaft. Dies deutet auf Monopolisierung/Prioritätseffekte (d.h. ruhende Gemeinschaften) bestimmter Arten in einzelnen Söllen hin. Da Umweltfilterung der dominierende Prozess für die Strukturierung der Zooplanktongemeinschaften ist, könnte dieses System durch künftige Landnutzungsänderungen, Verschmutzung und Klimawandel erheblich beeinflusst werden. KW - Zooplankton KW - Metacommunity KW - B. calyciflorus species complex KW - adaptation KW - hybridization KW - Metagemeinschaft KW - Anpassung KW - Hybridisierung Y1 - 2023 ER - TY - JOUR A1 - Lohmann, Dirk A1 - Guo, Tong A1 - Tietjen, Britta T1 - Zooming in on coarse plant functional types-simulated response of savanna vegetation composition in response to aridity and grazing JF - Theoretical ecology N2 - Precipitation and land use in terms of livestock grazing have been identified as two of the most important drivers structuring the vegetation composition of semi-arid and arid savannas. Savanna research on the impact of these drivers has widely applied the so-called plant functional type (PFT) approach, grouping the vegetation into two or three broad types (here called meta-PFTs): woody plants and grasses, which are sometimes divided into perennial and annual grasses. However, little is known about the response of functional traits within these coarse types towards water availability or livestock grazing. In this study, we extended an existing eco-hydrological savanna vegetation model to capture trait diversity within the three broad meta-PFTs to assess the effects of both grazing and mean annual precipitation (MAP) on trait composition along a gradient of both drivers. Our results show a complex pattern of trait responses to grazing and aridity. The response differs for the three meta-PFTs. From our findings, we derive that trait responses to grazing and aridity for perennial grasses are similar, as suggested by the convergence model for grazing and aridity. However, we also see that this only holds for simulations below a MAP of 500 mm. This combined with the finding that trait response differs between the three meta-PFTs leads to the conclusion that there is no single, universal trait or set of traits determining the response to grazing and aridity. We finally discuss how simulation models including trait variability within meta-PFTs are necessary to understand ecosystem responses to environmental drivers, both locally and globally and how this perspective will help to extend conceptual frameworks of other ecosystems to savanna research. KW - Traits KW - Dryland KW - Degradation KW - Shrub encroachment KW - Simulation KW - Eco-hydrological model KW - EcoHyD Y1 - 2018 U6 - https://doi.org/10.1007/s12080-017-0356-x SN - 1874-1738 SN - 1874-1746 VL - 11 IS - 2 SP - 161 EP - 173 PB - Springer CY - Heidelberg ER - TY - THES A1 - Lengefeld, Jan T1 - Zirkulardichroismus-Messungen mit Synchrotronstrahlung am BESSY : Möglichkeiten und Grenzen bei der Untersuchung biologischer Proben T1 - Synchrotron radiation circular dichroism measurements at BESSY : potentials and limitations investigating biological samples N2 - In dieser Arbeit wurden die Möglichkeiten und Grenzen für Zirkulardichroismus-Messungen mit Synchrotronstrahlung untersucht. Dazu wurde ein Messaufbau für Zirkulardichroismus-Messungen an zwei Strahlrohren am Berliner Elektronenspeicherring für Synchrotronstrahlung eingesetzt, die für Messungen im Bereich des ultravioletten Lichts geeignet sind. Eigenschaften der Strahlrohre und des Messaufbau wurden in einigen wichtigen Punkten mit kommerziellen Zirkulardichroismus-Spektrometern verglichen. Der Schwerpunkt lag auf der Ausdehnung des zugänglichen Wellenlängenbereichs unterhalb von 180 nm zur Untersuchung des Zirkulardichroismus von Proteinen in diesem Bereich. In diesem Bereich ist es nicht nur die Lichtquelle sondern vor allem die Absorption des Lichts durch Wasser, die den Messbereich bei der Messung biologischer Proben in wässriger Lösung einschränkt. Es wurden Bedingungen gefunden, unter denen der Messbereich auf etwa 160 nm, in einigen Fällen bis auf 130 nm ausgedehnt werden konnte. Dazu musste die Pfadlänge deutlich reduziert werden und verschieden Probenküvetten wurden getestet. Der Einfluss der dabei auftretenden Spannungsdoppelbrechung in den Probenküvetten auf das Messsignal konnte mit einem alternativen Messaufbau deutlich reduziert werden. Systematische Fehler im Messsignal und auftretende Strahlenschäden begrenzen jedoch die Zuverlässigkeit der gemessenen Spektren. Bei Proteinfilmen schränkt die Absorption von Wasser den Messbereich kaum ein. Es wurden jedoch meist deutliche Unterschiede zwischen den Spektren von Proteinfilmen und den Spektren von Proteinen in wässriger Lösung festgestellt. Solange diese Unterschiede nicht minimiert werden können, stellen Proteinfilme keine praktikable Alternative zu Messungen in wässriger Lösung dar. N2 - The possibilities and limitations for synchrotron radiation circular dichroism measurements were investigated in this thesis. Therefore an experimental setup to measure circular dichroism was used at two beamlines at the “Berliner Elektronenspeicherring für Synchrotronstrahlung”(BESSY), which were suitable in the ultraviolet range of light. Properties of the beamlines and the experimental setup were compared to those of commercial circular dichroism spectrometer in some important points. The focus was on the extension of the accessible wavelength range below 180 nm, with the aim to investigate the circular dichroism of proteins in that range. It is not only the light source that limits measurements with aqueous solutions in that range, but mainly the absorption of the light by water. Conditions were found under which the wavelength range was extended to about 160 nm, in some cases even to 130 nm. To achieve this, a significant reduction of the pathlength was necessary. Several sample cells were tested for their usability. The effect of birefringence within the sample cells on the circular dichroism signal could be reduced strongly with an alternative experimental setup. However systematic errors in the circular dichroism signal and appearing radiation damage of the proteins limits the reliability of the measured spectra. By using protein films, the light absorption by water is not a problem anymore. However, significant differences between the circular dichroism spectra of protein films and proteins in aqueous solution occurred in most of the cases. Unless these differences can be eliminated, measuring protein films is not an alternative to measurements in aqueous solution. KW - Synchrotronstrahlung KW - Zirkulardichroismus KW - BESSY KW - Wasserabsorption KW - Protein KW - synchrotron radiation KW - circular dichroism KW - BESSY KW - water absorbance KW - protein Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44263 ER - TY - JOUR A1 - Bauer, Christian G. A1 - Eremenko, A. V. A1 - Ehrentreich-Förster, Eva A1 - Bier, Frank Fabian A1 - Makower, Alexander A1 - Halsall, H. B. A1 - Heineman, W. R. A1 - Scheller, Frieder W. T1 - Zeptomole-detecting biosensor for alkaline phosphatase in an electroche mical immunoassay for 2,4- dichlorophenoacetic acid Y1 - 1996 ER - TY - THES A1 - Brandt, Stephan Peter T1 - Zelltyp-spezifische Mikroanalyse von Arabidopsis thaliana-Blättern N2 - Im ersten Teil der Arbeit wurden Strategien zur Analyse von Transkripten erarbeitet. Die ersten Versuche zielten darauf ab, in mit Glaskapillaren genommenen Einzelzellproben verschiedener Gewebeschichten RT-PCR durchzuführen, um spezifische Transkripte nachweisen zu können. Dies gelang für eine Reihe von Genen aus verschiedenen Pflanzenspezies. Dabei konnten sowohl Transkripte stark wie auch schwach exprimierter Gene nachgewiesen werden. Für die Erstellung von Gewebe-spezifischen Expressionsprofilen war es notwendig, die in vereinigten Zellproben enthaltene mRNA zunächst zu amplifizieren, um eine ausreichende Menge für Arrayhybridisierungen zu erhalten. Vor der Vermehrung wurde die mRNA revers transkribiert. Es wurden daran anschließend verschiedene Amplifikationsstrategien getestet: Die neben Tailing, Adapterligation und anderen PCR-basierenden Protokollen getestete Arbitrary-PCR hat sich in dieser Arbeit als einfache und einzige Methode herausgestellt, die mit so geringen cDNA-Mengen reproduzierbar arbeitet. Durch Gewebe-spezifische Array-hybridisierungen mit der so amplifizierten RNA konnten schon bekannte Expressionsmuster verschiedener Gene, vornehmlich solcher, die an der Photosynthese beteiligt sind, beobachtet werden. Es wurden aber auch eine ganze Reihe neuer offensichtlich Gewebe-spezifisch exprimierter Gene gefunden. Exemplarisch für die differentiell exprimierten Gene konnte das durch Arrayhybridisierungen gefundene Expressionsmuster der kleinen Untereinheit von Rubisco verifiziert werden. Hierzu wurden Methoden zum Gewebe-spezifischen Northernblot sowie semiquantitativer und Echtzeit-Einzelzell-RT-PCR entwickelt. Im zweiten Teil der Arbeit wurden Methoden zur Analyse von Metaboliten einschließlich anorganischer Ionen verwendet. Es stellte sich heraus, daß die multiparallele Methode der Gaschromatographie-Massenspektrometrie keine geeignete Methode für die Analyse selbst vieler vereinigter Zellinhalte ist. Daher wurde auf Kapillarelektrophorese zurückgegriffen. Eine Methode, die mit sehr kleinen Probenvolumina auskommt, eine hohe Trennung erzielt und zudem extrem geringe Detektionslimits besitzt. Die Analyse von Kohlenhydraten und Anionen erfordert eine weitere Optimierung. Über UV-Detektion konnte die K+-Konzentration in verschiedenen Geweben von A. thaliana bestimmt werden. Sie lag in Epidermis und Mesophyll mit ca. 25 mM unterhalb der für andere Pflanzenspezies (Solanum tuberosum und Hordeum vulgare) publizierten Konzentration. Weiter konnte gezeigt werden, daß zwölf freie Aminosäuren mittels einer auf Kapillarelektrophorese basierenden Methode in vereinigten Zellproben von Cucurbita maxima identifiziert werden konnten. Die Übertragung der Methode auf A. thaliana-Proben muß jedoch weiter optimiert werden, da die Sensitivität selbst bei Laser induzierter Fluoreszenz-Detektion nicht ausreichte. Im dritten und letzten Teil der Arbeit wurde eine Methode entwickelt, die die Analyse bekannter wie unbekannter Proteine in Gewebe-spezifischen Proben ermöglicht. Hierzu wurde zur Probennahme mittels mechanischer Mikrodissektion eine alternative Methode zur Laser Capture Microdissection verwendet, um aus eingebetteten Gewebeschnitten distinkte Bereiche herauszuschneiden und somit homogenes Gewebe anzureichern. Aus diesem konnten die Proteine extrahiert und über Polyacrylamidgelelektrophorese separariert werden. Banden konnten ausgeschnitten, tryptisch verdaut und massenspektrometrisch die Primärsequenz der Peptidfragmente bestimmt werden. So konnten als Hauptproteine im Mesophyll die große Untereinheit von Rubisco sowie ein Chlorophyll bindendes Protein gefunden werden. Die in dieser Arbeit entwickelten und auf die Modellpflanze Arabidopsis thaliana angewandten Einzelzellanalysetechniken erlauben es in Zukunft, physiologische Prozesse besser sowohl räumlich als auch zeitlich aufzulösen. Dies wird zu einem detaillierteren Verständnis mannigfaltiger Vorgänge wie Zell-Zell-Kommunikation, Signalweiterleitung oder Pflanzen-Pathogen-Interaktionen führen. N2 - The subject of this thesis was the analysis of single plant cells in respect to their contents of i) transcripts, ii) inorganic cations and anions, iii) metabolites like amino acids and carbohydrates as well as iv) proteins. One task was the transfer of existing methods to single cell analysis on leaf tissues of the model plant Arabisopsis thaliana L., the second one was the refinement and the development, respectively, of new protocols for the analysis of such picoliter samples. For cell type specific sampling two different complimentary methods were applied: Using micro glass capillaries specific single cell contents could be harvested from intact plants, whereas typical sample volumes were in the picoliter range. Even the sampling of inner cell types such as companion cells could be demonstrated. Using mechanical micro dissection of embedded tissue a larger amount of homogenous tissue could be collected. Because single cell samples contain only femtogram amounts of mRNA, direct detection of transcripts is impossible. Therefore, two amplification protocols were applied to the cell samples: The first procedure makes use of specifically primed RT-PCR for amplification. Several genes derived from different plants and tissues could be detected after successful RT-PCR, including high as well as low expressed genes. The second method was developed to monitor the activity of many genes in parallel using array hybridisation with filters containing the cDNA of as many as 16.000 ESTs. For this purpose, unspecific RT-PCR as it is applied in the differential display was used to amplify different transcripts in just one reaction. However, in these tissue specific array hybridisations the expression patterns of several hundreds genes could be monitored. These included known tissue specific expression patterns (of mainly photosynthesis related genes) as well as a couple of unknown expression patterns. To verify the tissue specificity of gene activity some results were reconsidered using tissue specific northern blot hybridisations and real time RT-PCR, respectively. Secondly, metabolites (including inorganic ions) were investigated: Because gas chromatography-mass spectrometry does not reveal the sensitivity which in necessary for the analysis of even multiple pooled single cell samples capillary electrophoresis was applied for these studies. This method has a high potential as it needs only small amounts of starting material, has uncomparable low detection limits and exhibits a high number of theoretical plates. The analysis of inorganic anions and carbohydrates needs further optimisations. Using UV absorption-detection potassium could be detected in different cell types whereas the concentrations in mesophyll and epidermis were found around 25 mM each. These concentrations are lower than in other species as Solanum tuberosum or Hordeum vulgare. For investigations of amino acids the cell samples were derivatized to make the use of laser induced fluorescence-detection capable. In samples derived from pumpkin (Cucurbita maxima) mesophyll twelve amino acids could be detected and identified. The transfer of this method to A. thaliana derived samples exhibited no results which may be due to the low concentration of free amino acids in these plants. Finally, a method was developed with which the existence of known and unknown proteins in tissue specific samples could be monitored. For this, mechanical micro dissection was used to: After embedding and sectioning the tissue of interest was cut out by an vibrating steel chisel to get homogenous samples. The proteins contained in these tissue pieces were extracted and separated by one dimensional SDS polyacrylamid gel electrophoresis. Several protein bands could be detected after staining with either silver or coomassie blue stain. These bands were cut out and sequenced by mass spectrometry. The large subunit of rubisco as well as one chlorophyll binding protein could be identified as the major proteins within the mesophyll. The single cell analysis methods which were developed and applied to the model plant A. thaliana in this thesis allow a better spatial as well as temporal resolution of analysis. This will lead to a more detailed understanding of physiological processes like cell to cell communication, signalling or plant-pathogen interactions. KW - Einzelzellanalytik KW - minimal invasive Probennahme KW - Array Hybridisierung KW - RT-PCR KW - Kapillarelektrophorese KW - Fluoreszeinisothiocyanat KW - mechanische Mikrodis KW - single cell analysis KW - minimal invasive sampling KW - single cell sammpling and analysis (SCSA) KW - array hybridisation KW - RT-PCR KW - capillary electrophoresis KW - fl Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0000410 ER - TY - JOUR A1 - Grönke, Ottokar A1 - Klepel, Gert T1 - Zelle, Einzeller, Vielzeller Y1 - 2000 SN - 3-06-010768-8 ER - TY - THES A1 - Pacholsky, Dirk T1 - Zell-Zell- und Zell-Matrix-Kontakte während der Muskelentwicklung N2 - Im Rahmen dieser Arbeit wurden zwei humane Varianten des von Wang et al., 1999, erstmals beschriebenen muskelspezifischen Proteins Xin (Huhn und Maus) über Sequenzanalyse, Immunofluoreszenzmikroskopie, Transfektionsstudien und biochemischer Analyse näher charakterisiert. Die Proteine wurden mit human Xin related proteins 1 und 2 – hXirp1 und 2 –bezeichnet. Die Xin-Proteine enthielten bisher unbekannte, sowie spezifische, repetitive Motive, die aus jeweils mindestens 16 Aminosäuren bestanden. Ihre Aminosäuresequenz, mit einer Vielzahl weiterer putativer Motivsequenzen, verwies auf eine potentielle Funktion von hXirp als Adapterprotein in Muskelzellen. Das hier näher untersuchte hXirp1 lokalisierte an den Zell-Matrix-Verbindungen der Muskel-Sehnen-Übergangszone im Skelettmuskel, sowie an den Zell-Zell-Verbindungen der Glanzstreifen im Herzmuskel. Während der Muskelentwicklung zeigte hXirp1 eine sehr frühe Expression, zusammen mit einer prägnanten Lokalisation an den Prämyofibrillen und deren Verankerungsstrukturen, die auf eine Funktion des Proteins in der Myofibrillogenese deuten. Ektopische Expressionen von hXirp1 in einer Vielzahl von Nichtmuskel-Kulturzellen zeigten wiederum eine Lokalisation des Proteins an den Zell-Matrix-Kontakten dieser Zellen. Am Beispiel von hXirp1 und 2 wurde stellvertretend für die Familie der Xin-Proteine gezeigt, daß es sich bei den repetitiven Motiven um neuartige, F-Aktin bindende Sequenzmotive handelte. Die Xin-Proteine können somit als muskelspezifische, aktinbindende, potentielle Adapterproteine bezeichnet werden, denen eine strukturelle und funktionelle Beteiligung an der Verankerung der Myofibrillen im adulten Muskel, wie auch während der Myofibrillogenese zukommt. N2 - The scope of this work was a further characterization of two human variants of the protein Xin which was reported for chicken and mouse in 1999 by Wang et al. Therefor sequence analysis, immunofluorescence microscopy, transfection studies and biochemical approaches were utilized. The proteins were named human Xin related proteins 1 und 2 – hXirp1 und 2. Xin-proteins possess specific repetitive motives consisting of a minimum of 16 amino acids each. Concerning further putative motive sequences hXirp is a potential adapter protein in the muscle cell. hXirp1 localized within the cell-matrix-contacts of the myotendinous junction in skeletal muscle as well as within the cell-cell-contacts of the intercalated disc in the cardiac muscle. During the development of muscle cells hXirp1 showed early expression as well as concise localization to premyofibrils and their anchorage structures indicating a potential role for this protein in myofibrillogenesis. Ectopic expression of hXirp1 in several non-muscle cells again revealed localization of this protein to cell-matrix contacts. Considering hXirp1 and 2 as an example for all Xin-proteins it was shown that the repetitive motives are new actin binding motives. The data indicated the Xin-proteins as muscle specific, actin binding and potential adapter proteins with implications in structure and function of anchorage of myofibrils in adult muscle and myofibrillogenesis. KW - Muskel KW - Muskel-Sehnen-Verbindung KW - Glanzstreifen KW - Xin KW - muscle KW - myotendinous junction KW - intercalated disc KW - Xin Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0001161 ER - TY - JOUR A1 - Cui, Xiao A1 - Lv, Yang A1 - Chen, Miaolin A1 - Nikoloski, Zoran A1 - Twell, David A1 - Zhang, Dabing T1 - Young Genes out of the Male: An Insight from Evolutionary Age Analysis of the Pollen Transcriptome JF - Molecular plant N2 - The birth of new genes in genomes is an important evolutionary event. Several studies reveal that new genes in animals tend to be preferentially expressed in male reproductive tissues such as testis (Betran et al., 2002; Begun et al., 2007; Dubruille et al., 2012), and thus an "out of testis' hypothesis for the emergence of new genes has been proposed (Vinckenbosch et al., 2006; Kaessmann, 2010). However, such phenomena have not been examined in plant species. Here, by employing a phylostratigraphic method, we dated the origin of protein-coding genes in rice and Arabidopsis thaliana and observed a number of young genes in both species. These young genes tend to encode short extracellular proteins, which may be involved in rapid evolving processes, such as reproductive barriers, species specification, and antimicrobial processes. Further analysis of transcriptome age indexes across different tissues revealed that male reproductive cells express a phylogenetically younger transcriptome than other plant tissues. Compared with sporophytic tissues, the young transcriptomes of the male gametophyte displayed greater complexity and diversity, which included a higher ratio of anti-sense and inter-genic transcripts, reflecting a pervasive transcription state that facilitated the emergence of new genes. Here, we propose that pollen may act as an "innovation incubator' for the birth of de novo genes. With cases of male-biased expression of young genes reported in animals, the "new genes out of the male' model revealed a common evolutionary force that drives reproductive barriers, species specification, and the upgrading of defensive mechanisms against pathogens. KW - pollen KW - evolution KW - young genes KW - transcriptome Y1 - 2015 U6 - https://doi.org/10.1016/j.molp.2014.12.008 SN - 1674-2052 SN - 1752-9867 VL - 8 IS - 6 SP - 935 EP - 945 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Mirhaj, M. A1 - Boit, Alice A1 - Razzak, M. A. A1 - Wahab, M. A. T1 - Yield performance comparison between cultures of rice cum prawn (Macrobrachium rosenbergii) and rice cum fish (Cyprinus carpio, Oreochromis niloticus) in North-Eastern Bangladesh JF - Aquaculture : an international journal devoted to research on the exploration and improvement of all aquatic food resources, both floristic and faunistic, from freshwater, brackish and marine environment, related directly or indirectly to human consumption N2 - Integrated and concurrent cultures in rice fields are a promising approach to sustainable farming as the demand for aquacultural and agricultural products continues to grow while land and water resources become increasingly scarce. Prawn farming mainly takes place in coastal regions in improved extensive to semi-intensive aquacultures but a trend to shift the industry to inland regions has been noticed. This inland study in Northern Bangladesh used different input regimes such as fertilizer and additional feed to compare the performance of prawn and fish in flooded paddy fields in regard to water quality measurements. Maximal net yields and body weight gain with minimized negative impact on water quality were found when initial body weights of prawn were optimized. Regarding yield factors in reference to the reduction of costs due to the avoidance of expensive fertilizer/feed and effort, prawn performed better than integrated fish cultures considering a higher market value of prawn with net yields of up to 97 +/- 55 kg ha(-1) for unfed and 151 +/- 61 kg ha(-1) for fed treatments. Rice yields of up to 4.7 +/- 0.1 t ha(-1) for unfed and 4.4 +/- 0.1 t ha(-1) were achieved for fed treatments. The findings suggest that for small scale farmers, prawn cum rice cultures are an economically profitable and comparatively easily manageable alternative to rice cum fish cultures. KW - Rice cum prawn culture KW - Macrobrachium rosenbergii KW - Sustainable aquaculture KW - Polyculture Y1 - 2013 U6 - https://doi.org/10.1016/j.aquaculture.2013.01.038 SN - 0044-8486 VL - 392 IS - 5 SP - 26 EP - 33 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Lilie, Hauke A1 - Baer, Dorit A1 - Kettner, Karina A1 - Weininger, Ulrich A1 - Balbach, Jochen A1 - Naumann, Manfred A1 - Mueller, Eva-Christina A1 - Otto, Albrecht A1 - Gast, Klaus A1 - Golbik, Ralph A1 - Kriegel, Thomas T1 - Yeast hexokinase isoenzyme ScHxk2 stability of a two-domain protein with discontinuous domains JF - Protein engineering design & selection N2 - The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional H-1 NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about Delta G = -22 kJ mol(-1). KW - dynamic light scattering KW - NMR KW - ScHxk2 KW - stability KW - transition intermediate Y1 - 2011 U6 - https://doi.org/10.1093/protein/gzq098 SN - 1741-0126 VL - 24 IS - 1-2 SP - 79 EP - 87 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Lilie, Hauke A1 - Bär, Dorit A1 - Kettner, Karina A1 - Weininger, Ulrich A1 - Balbach, Jochen A1 - Naumann, Manfred A1 - Müller, Eva-Christina A1 - Otto, Albrecht A1 - Gast, Klaus A1 - Golbik, Ralph T1 - Yeast hexokinase isoenzyme ScHxk2 : stability of a two-domain protein with discontinuous domains N2 - The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional 1H NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about ;G = ;22 kJ mol;1. Y1 - 2011 UR - http://peds.oxfordjournals.org/content/24/1-2/79.long SN - 0269-2139 ER - TY - JOUR A1 - Albrecht, Tanja A1 - Haebel, Sophie A1 - Koch, Anke A1 - Krause, Ulrike A1 - Eckermann, Nora A1 - Steup, Martin T1 - Yeast glycogenin (Glg2p) produced in Escherichia coli is simultaneously glucosylated at two vicinal tyrosin residues but results in a reduced bacterial glycogen accumulation N2 - Saccharomyces cerevisiae possesses two glycogenin isoforms (designated as Glg1p and Glg2p) that both contain a conserved tyrosine residue, Tyr232. However, Glg2p possesses an additional tyrosine residue, Tyr230 and therefore two potential autoglucosylation sites. Glucosylation of Glg2p was studied using both matrix-assisted laser desorption ionization and electrospray quadrupole time of flight mass spectrometry. Glg2p, carrying a C-terminal (His(6)) tag, was produced in Escherichia coli and purified. By tryptic digestion and reversed phase chromatography a peptide (residues 219-246 of the complete Glg2p sequence) was isolated that contained 4-25 glucosyl residues. Following incubation of Glg2p with UDPglucose, more than 36 glucosyl residues were covalently bound to this peptide. Using a combination of cyanogen bromide cleavage of the protein backbone, enzymatic hydrolysis of glycosidic bonds and reversed phase chromatography, mono- and diglucosylated peptides having the sequence PNYGYQSSPAM were generated. MS/MS spectra revealed that glucosyl residues were attached to both Tyr232 and Tyr230 within the same peptide. The formation of the highly glucosylated eukaryotic Glg2p did not favour the bacterial glycogen accumulation. Under various experimental conditions Glg2p-producing cells accumulated approximately 30% less glycogen than a control transformed with a Glg2p lacking plasmid. The size distribution of the glycogen and extractable activities of several glycogen-related enzymes were essentially unchanged. As revealed by high performance anion exchange chromatography, the intracellular maltooligosaccharide pattern of the bacterial cells expressing the functional eukaryotic transgene was significantly altered. Thus, the eukaryotic glycogenin appears to be incompatible with the bacterial initiation of glycogen biosynthesis Y1 - 2004 ER - TY - JOUR A1 - Redelberger, David A1 - Seduk, Farida A1 - Genest, Olivier A1 - Mejean, Vincent A1 - Leimkühler, Silke A1 - Iobbi-Nivol, Chantal T1 - YcdY Protein of Escherichia coli, an Atypical Member of the TorD Chaperone Family JF - Journal of bacteriology N2 - The TorD family of specific chaperones is divided into four subfamilies dedicated to molybdoenzyme biogenesis and a fifth one, exemplified by YcdY of Escherichia coli, for which no defined partner has been identified so far. We propose that YcdY is the chaperone of YcdX, a zinc protein involved in the swarming motility process of E. coli, since YcdY interacts with YcdX and increases its activity in vitro. Y1 - 2011 U6 - https://doi.org/10.1128/JB.05927-11 SN - 0021-9193 VL - 193 IS - 23 SP - 6512 EP - 6516 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Pacholsky, Dirk A1 - Vakeel, Padmanabhan A1 - Himmel, Mirko A1 - Lowe, T. A1 - Stradal, T. A1 - Rottner, K. A1 - Fürst, Dieter Oswald A1 - vanderVen, Peter F. M. T1 - Xin repeats define a novel actin-binding motif N2 - Xin is a protein that is expressed during early developmental stages of cardiac and skeletal muscles. Immunolocalization studies indicated a peripheral localization in embryonic mouse heart, where Xin localizes with beta- catenin and N-cadherin. In adult tissues, Xin is found primarily in the intercalated discs of cardiomyocytes and the myotendinous junctions of skeletal muscle cells, both specialized attachment sites of the myofibrillar ends to the sarcolemma. A large part of the Xin protein consists of unique 16 amino acid repeats with unknown function. We have investigated the characteristics of the Xin repeats by transfection experiments and actin-binding assays and ascertained that, upon expression in cultured cells, these repeats bind to and stabilize the actin-based cytoskeleton. In vitro co- sedimentation assays with skeletal muscle actin indicated that they not only directly bind actin filaments, but also have the capability of arranging microfilaments into networks that sediment upon low-speed centrifugation. Very similar repeats were also found in Xin-repeat protein 2' (XIRP2), a novel protein that seems to be expressed mainly in striated muscles. Human XIRP2 contains 28 Xin repeats with properties identical to those of Xin. We conclude that the Xin repeats define a novel, repetitive actin-binding motif present in at least two different muscle proteins. These Xin- repeat proteins therefore constitute the first two members of a novel family of actin-binding proteins Y1 - 2004 SN - 0021-9533 ER - TY - JOUR A1 - Kalimuthu, Palraj A1 - Leimkühler, Silke A1 - Bernhardt, Paul V. T1 - Xanthine dehydrogenase electrocatalysis autocatalysis and novel activity JF - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry N2 - The enzyme xanthine dehydrogenase (XDH) from the purple photosynthetic bacterium Rhodobacter capsulatus catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid as part of purine metabolism. The native electron acceptor is NAD(+) but herein we show that uric acid in its 2-electron oxidized form is able to act as an artificial electron acceptor from XDH in an electrochemically driven catalytic system. Hypoxanthine oxidation is also observed with the novel production of uric acid in a series of two consecutive 2-electron oxidation reactions via xanthine. XDH exhibits native activity in terms of its pH optimum and inhibition by allopurinol. Y1 - 2011 U6 - https://doi.org/10.1021/jp111809f SN - 1520-6106 VL - 115 IS - 11 SP - 2655 EP - 2662 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schubert, Dieter A1 - Schluckebier, Gerd A1 - Backmann, Jan A1 - Granzien, Joachim A1 - Kisker, Caroline A1 - Choe, Hui-Woog A1 - Hahn, Ulrich A1 - Pfeil, Wolfgang A1 - Saenger, Wolfram T1 - X-ray crystallographic and calorimetric studies of the effects of the mutation Trp59Tyr in ribonuclease T1 Y1 - 1994 ER - TY - GEN A1 - Prát, Tomáš A1 - Hajny ́, Jakub A1 - Grunewald, Wim A1 - Vasileva, Mina A1 - Molnár, Gergely A1 - Tejos, Ricardo A1 - Schmid, Markus A1 - Sauer, Michael A1 - Friml, Jiří T1 - WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1123 KW - apical-basal axis KW - arabidopsis-thaliana KW - root gravitropism KW - DNA-binding KW - gene-expression KW - transport KW - efflux KW - canalization KW - plants KW - phosphorylation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446331 SN - 1866-8372 IS - 1123 ER - TY - JOUR A1 - Prat, Tomas A1 - Hajny, Jakub A1 - Grunewald, Wim A1 - Vasileva, Mina A1 - Molnar, Gergely A1 - Tejos, Ricardo A1 - Schmid, Markus A1 - Sauer, Michael A1 - Friml, Jiří T1 - WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity JF - PLoS Genetics : a peer-reviewed, open-access journal N2 - Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development. Y1 - 2018 U6 - https://doi.org/10.1371/journal.pgen.1007177 SN - 1553-7404 VL - 14 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Klingstrom, Tomas A1 - Soldatova, Larissa A1 - Stevens, Robert A1 - Roos, T. Erik A1 - Swertz, Morris A. A1 - Müller, Kristian M. A1 - Kalas, Matus A1 - Lambrix, Patrick A1 - Taussig, Michael J. A1 - Litton, Jan-Eric A1 - Landegren, Ulf A1 - Bongcam-Rudloff, Erik T1 - Workshop on laboratory protocol standards for the molecular methods database JF - New biotechnology N2 - Management of data to produce scientific knowledge is a key challenge for biological research in the 21st century. Emerging high-throughput technologies allow life science researchers to produce big data at speeds and in amounts that were unthinkable just a few years ago. This places high demands on all aspects of the workflow: from data capture (including the experimental constraints of the experiment), analysis and preservation, to peer-reviewed publication of results. Failure to recognise the issues at each level can lead to serious conflicts and mistakes; research may then be compromised as a result of the publication of non-coherent protocols, or the misinterpretation of published data. In this report, we present the results from a workshop that was organised to create an ontological data-modelling framework for Laboratory Protocol Standards for the Molecular Methods Database (MolMeth). The workshop provided a set of short- and long-term goals for the MolMeth database, the most important being the decision to use the established EXACT description of biomedical ontologies as a starting point. Y1 - 2013 U6 - https://doi.org/10.1016/j.nbt.2012.05.019 SN - 1871-6784 VL - 30 IS - 2 SP - 109 EP - 113 PB - Elsevier CY - Amsterdam ER -