@article{KonigJakubiczkaWieackeretal.1993, author = {Konig, Anja and Jakubiczka, Sybille and Wieacker, Peter and Schl{\"o}sser, Hans W. and Gessler, Manfred}, title = {Further evidence that imbalance of WT1 isoforms may be involved in Denys-Drash syndrome}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59167}, year = {1993}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{GesslerBruns1988, author = {Gessler, Manfred and Bruns, Gail A. P.}, title = {Molecular mapping and cloning of the breakpoints of a chromosome 11p14.1-p13 deletion associated with the AGR syndrome}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59264}, year = {1988}, abstract = {Chromosome 11p13 is frequently rearranged in individuals with the WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) or parts of this syndrome. To map the cytogenetic aberrations molecularly, we screened DNA from cell Unes with known WAGR-related chromosome abnormalities for rearrangements with pulsed fleld gel (PFG) analysis using probes deleted from one chromosome 11 homolog of a WAGR patient. The first alteration was detected in a cell line from an individual with aniridia, genitourinary anomalies, mental retardation, and a deletion described as 11p14.1-p13. We have located one breakpoint close to probe HU11-164B and we have cloned both breakpoint sites as well as the junctional fragment. The breakpoints subdivide current intervals on the genetic map, and the probes for both sides will serve as important additional markers for a long-range restriction map of this region. Further characterization and sequencing of the breakpoints may yield insight into the mechanisms by which these deletions occur.}, subject = {Biochemie}, language = {en} } @article{BarnekowGessler1986, author = {Barnekow, Angelika and Gessler, Manfred}, title = {Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59278}, year = {1986}, abstract = {Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60c-src tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60c-src kinase.}, subject = {Biochemie}, language = {en} } @article{GesslerBarnekow1984, author = {Gessler, Manfred and Barnekow, Angelika}, title = {Differential expression of the cellular oncogenes c-src and c-yes in embryonal and adult chicken tissues}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59289}, year = {1984}, abstract = {The cellular onc-genes c-src and c-yes are expressed very differently during chicken embryonic development. The c-src mRNA and its translational product are detectable at high levels in brain extracts of chicken embryos and adult chickens, whereas muscle extracts show an age-dependent decrease in the amounts of c-src-specific mRNA and pp60c-src kinase activity. In contrast, the Ievels of c-yes mRNA in brain, heart, and muscle are relatively low in early embryonic stages and increase later on to values comparable to those found for liver, while in adult animals the pattern of c-yes expression is similar to that of the c-src gene. From the close correlation between the Ievels of pp60c-src, its enzymatic activity, and its corresponding mRNA at a given stage of development and in given tissues, it appears that the expression of pp60c-src is primarily controlled at the level of transcription. It is suggested that because of the different patterns of expression, the two cellular oncogenes, c-src and c-yes, play different roles in cell proliferation during early embryonic stages as weil as in ensuing differentiation processes.}, subject = {Biochemie}, language = {en} } @article{SchwartzNeveEisenmanetal.1994, author = {Schwartz, Faina and Neve, Rachel and Eisenman, Robert and Gessler, Manfred and Bruns, Gail}, title = {A WAGR region gene between PAX-6 and FSHB expressed in fetal brain}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59125}, year = {1994}, abstract = {Developmental delay or mental retardation is a frequent component of multi-system anomaly syndromes associated with chromosomal deletions. Isolation of genes involved in the mental dysfunction in these disorders should define loci important in brain formation or function. We have identified a highly conserved locus in the distal part of 11 p 13 that is prominently expressed in fetal brain. Minimal expression is observed in a number of other fetal tissues. The gene maps distal to PAX-6 but proximal to the loci for brain-derived neurotrophic factor (BDNF) and the beta subunit of follicle stimulating hormone (FSHB), within a region previously implicated in the mental retardation component of some WAGR syndrome patients. Within fetal brain, the corresponding transcript is prominent in frontal, motor and primary visual cortex as weil as in the caudate-putamen. The characteristics of this gene, including the striking evolutionary conservation at the locus, suggest that the encoded protein may function in brain development.}, subject = {Biochemie}, language = {en} } @phdthesis{Dippacher2011, author = {Dippacher, Sonja}, title = {Morphologische und molekularbiologische Untersuchungen zur Bedeutung der Serin-Threonin-Proteinkinase SRPK79D in Drosophila melanogaster}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70937}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Die intakte Signal{\"u}bertragung im animalischen Nervensystem erfordert eine an richtiger Stelle ausgebildete funktionsf{\"a}hige Synapse zwischen zwei Nervenzellen bzw. zwischen Nerv und Muskel. In der vorliegenden Arbeit wurde eine Mutante von Drosophila melanogaster untersucht, bei der es zu Ver{\"a}nderungen der Verteilung eines wichtigen Organisationsproteins der synaptischen aktiven Zone kommt. Ein wichtiges Ergebnis der Untersuchungen ist die Beobachtung, dass es in der Mutante zu einer ektopen Ausbildung von Elementen aktiver Zonen in Axonen kommt. In den Arbeitsgruppen von E. Buchner und S. Sigrist ist bereits das Protein Bruchpilot (BRP) charakterisiert worden, das Bestandteil der pr{\"a}synaptischen Ribbons, bei Drosophila als T-bars bezeichnet, ist. Bei der Suche nach Interaktionspartnern von BRP, ist eine Serin-Arginin-Protein spezifische Kinase SRPK79D entdeckt worden, die offenbar an der Regulation des Aufbaus der Tbars beteiligt ist (Nieratschker et al., 2009). Es gibt vier verschiedene Isoformen der Kinase. Werden nur zwei Isoformen der Kinase (SRPK79D-RB und -RE) exprimiert bzw. das Gen der Kinase komplett ausgeschaltet, findet man Ansammlungen von BRP als immunreaktive Aggregate in der Immunfluoreszenz- F{\"a}rbung von larvalen Motoneuron-Axonen (Nieratschker, 2008). Es ist unser {\"u}bergeordnetes Ziel, die Funktion und den molekularen Signalweg der Kinase SRPK79D zu entschl{\"u}sseln. Ein Ziel der vorliegenden Arbeit war es, PB-Protein in Reinform f{\"u}r eine Affinit{\"a}tsreinigung eines PB-Antik{\"o}rpers zu gewinnen, um in nachfolgenden Untersuchungen die Lokalisation dieser Kinase-Isoform zu untersuchen. Die Proteinreinigung war erfolgreich, aber es gelang nicht, eine f{\"u}r eine Affinit{\"a}tsreinigung ausreichende Menge des Proteins zu isolieren. Ein weiterer Versuch, Lokalisationsuntersuchungen zur Expression der Kinase in Drosophila- Embryonen durchzuf{\"u}hren, war ebenfalls nicht erfolgreich. Obwohl die Herstellung einer f{\"u}r die SRPK79D mRNA spezifischen RNA Sonde f{\"u}r die in-Situ-Hybridisierung gelang, war die Sensitivit{\"a}t dieser Sonde nicht hoch genug, um die Lokalisation vornehmen zu k{\"o}nnen. Eindeutige und aufschlussreiche Ergebnisse dagegen ergab die Untersuchung der Ultrastruktur der BRP-Ansammlungen in den larvalen Motornerven. Als deren Korrelat fanden sich elektronenmikroskopisch charakteristische Ansammlungen elektronendichter intraaxonaler Strukturen, deren Form {\"A}hnlichkeiten zu T-bars aufwies und die von Vesikeln umgeben waren. Die elektronendichten Strukturen zeigten zahlreiche Formvariationen, die wie Ansammlungen von T-bars nebeneinander bzw. „miteinander verklebte" T-bars oder wie zerst{\"o}rte T-bars aussahen. In einer nachfolgenden Studie wurde durch eine immun-elektronenmikroskopische Untersuchung gezeigt, dass diese Strukturen in der Tat BRP enthalten (Nieratschker et al., 2009). Ergebnis der Untersuchungen der vorliegenden Arbeit war der Nachweis, dass prinzipiell {\"a}hnliche Aggregate auch im Wildtyp gelegentlich gefunden werden, dass sie aber in Mutanten signifikant h{\"a}ufiger vorkommen und auch einen signifikant h{\"o}heren Durchmesser aufweisen. Doppelimmunreaktionen mit Antik{\"o}rpern, die den C- bzw. N-terminalen Bereich von BRP erkennen, belegten dar{\"u}ber hinaus, dass in den Aggregaten das vollst{\"a}ndige BRP-Protein vorliegt. Angeregt durch die Ultrastrukturbefunde von mit den elektronendichten Strukturen in den Aggregaten assoziierten Vesikeln wurde in weiteren Doppelimmunreaktionen untersucht, ob ein typisches Protein synaptischer Vesikel neuromuskul{\"a}rer Synapsen in Drosophila, der vesikul{\"a}re Glutamattransporter (DVGlut), in den BRP-Ansammlungen nachweisbar ist. W{\"a}hrend Kolokalisation von BRP und DVGlut in aktiven Zonen pr{\"a}synaptischer Boutons nachgewiesen werden konnte, war der Vesikelmarker in BRP-Aggregaten nicht kolokalisiert. Die Ergebnisse belegen, dass die Kinase SRPK79D f{\"u}r die Vermeidung einer ektopen Bildung von BRP-enthaltenden, elektronenmikroskopisch atypischen aktiven Zonen {\"a}hnelnden Strukturen in larvalen Motoneuronaxonen notwendig ist. Die in diesen Aggregaten regelm{\"a}ßig zu beobachtenden Vesikel {\"a}hneln morphologisch synaptischen Vesikeln, besitzen aber keine daf{\"u}r typischen Vesikelmarker.}, subject = {Bruchpilot}, language = {de} } @phdthesis{Schuelein2011, author = {Sch{\"u}lein, Christina}, title = {Die Regulation von Fbw7 durch PI3K-abh{\"a}ngige Phosphorylierung und Charakterisierung eines konditionalen Usp28-Knockout-Mausmodells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70963}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Das Proto-Onkoprotein Myc ist an der Entstehung und Aufrechterhaltung einer Vielzahl humaner Tumore entscheidend beteiligt. In der vorliegenden Arbeit wurde Serin 227 in Fbw7 als Ziel f{\"u}r eine PI3K-abh{\"a}ngige Phosphorylierung identifiziert. Diese Phosphorylierung f{\"u}hrt zur Stabilisierung von Fbw7 und steigert die F{\"a}higkeit von Fbw7, Substratproteine zu ubiquitinieren und abzubauen. Um die Bedeutung von Usp28 in der Myc-induzierten Tumorentstehung und in der normalen Gewebehom{\"o}ostase zu untersuchen, wurde ein konditionales Knockout-Mausmodell f{\"u}r Usp28 charakterisiert. M{\"a}use mit einer Keimbahndeletion von Usp28 sind lebensf{\"a}hig, fertil und ph{\"a}notypisch unauff{\"a}llig. Weder in Organen der Usp28-negativen Tiere, noch in entsprechenden murinen embryonalen Fibroblasten kann eine Destabilisierung von Myc festgestellt werden. Allerdings zeigen Fibroblasten mit heterozygotem Usp28-Verlust einen Proliferationsdefekt und in Eμ-Myc-Lymphomen dieses Genotyps werden tendenziell niedrigere Myc-Proteinmengen gefunden. Das tumorfreie {\"U}berleben ist bei den Eμ-Myc; Usp28 +/- Tieren verl{\"a}ngert.}, subject = {Myc}, language = {de} } @phdthesis{Homola2011, author = {Homola, Gy{\"o}rgy {\´A}d{\´a}m}, title = {Functional and Microstructural MRI of the Human Brain Revealing a Cerebral Network Processing the Age of Faces}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-56740}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Although age is one of the most salient and fundamental aspects of human faces, its processing in the brain has not yet been studied by any neuroimaging experiment. Automatic assessment of temporal changes across faces is a prerequisite to identifying persons over their life-span, and age per se is of biological and social relevance. Using a combination of evocative face morphs controlled for global optical flow and functional magnetic resonance imaging (fMRI), we segregate two areas that process changes of facial age in both hemispheres. These areas extend beyond the previously established face-sensitive network and are centered on the posterior inferior temporal sulcus (pITS) and the posterior angular gyrus (pANG), an evolutionarily new formation of the human brain. Using probabilistic tractography and by calculating spatial cross-correlations as well as creating minimum intersection maps between activation and connectivity patterns we demonstrate a hitherto unrecognized link between structure and function in the human brain on the basis of cognitive age processing. According to our results, implicit age processing involves the inferior temporal sulci and is, at the same time, closely tied to quantity decoding by the presumed neural systems devoted to magnitudes in the human parietal lobes. The ventral portion of Wernicke's largely forgotten perpendicular association fasciculus is shown not only to interconnect these two areas but to relate to their activations, i.e. to transmit age-relevant information. In particular, post-hoc age-rating competence is shown to be associated with high response levels in the left angular gyrus. Cortical activation patterns related to changes of facial age differ from those previously elicited by other fixed as well as changeable face aspects such as gender (used for comparison), ethnicity and identity as well as eye gaze or facial expressions. We argue that this may be due to the fact that individual changes of facial age occur ontogenetically, unlike the instant changes of gaze direction or expressive content in faces that can be "mirrored" and require constant cognitive monitoring to follow. Discussing the ample evidence for distinct representations of quantitative age as opposed to categorical gender varied over continuous androgyny levels, we suggest that particular face-sensitive regions interact with additional object-unselective quantification modules to obtain individual estimates of facial age.}, subject = {Gesicht}, language = {en} } @phdthesis{Dwertmann2012, author = {Dwertmann, Anne}, title = {Impact of the Tumor Suppressor Arf on Miz1 and Sumoylation of Myc and Miz1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71876}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Upon oncogenic stress, the tumor suppressor Arf can induce irreversible cell cycle arrest or apoptosis, depending on the oncogenic insult. In this study, it could be shown that Arf interacts with Myc and the Myc-associated zinc-finger protein Miz1 to facilitate repression of genes involved in cell adhesion. Formation of a DNA-binding Arf/Myc/Miz1 complex disrupts interaction of Miz1 with its coactivator nucleophosmin and induces local heterochromatinisation, causing cells to lose attachment and undergo anoikis. The assembly of the complex relies on Myc, which might explain why high Myc levels trigger apoptosis and not cell cycle arrest in the Arf response. This mechanism could play an important role in eliminating cells harboring an oncogenic mutation. Arf furthermore induces sumoylation of Miz1 at a specific lysine by repressing the desumoylating enzyme Senp3. A sumoylation-deficient mutant of Miz1 however does not show phenotypic differences under the chosen experimental conditions. Myc can also be modified by Sumo by multisumoylation at many different lysines, which is unaffected by Arf. The exact mechanism and effect of this modification however stays unsolved.}, subject = {Apoptosis}, language = {en} } @phdthesis{Karunakaran2012, author = {Karunakaran, Karthika}, title = {Mechanisms of apoptosis regulation in human cells infected with Simkania negevensis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72098}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Chlamydiales are obligate intracellular gram-negative bacteria that have gained high medical relevance. These important human pathogens cause diverse diseases including trachoma and wide spread sexually transmitted diseases. Chlamydia establishes membrane bound inclusions in the host cell and loots the host for nutritional requirements. Infections are usually recognized by the host immune system and eliminated systematically, by triggering apoptosis. However, the pathogen Chlamydia has evolved various strategies to prevent the detection as well as protect the invaded cell against apoptosis or any other form of cell death. The evolutionary conservation of cell death regulation has not been investigated in the order Chlamydiales, which also includes Chlamydia-like organisms with a broader host spectrum. The present study was aimed at investigating the apoptotic response of human cells infected with the Chlamydia-like organism Simkania negevensis (Sn). Simkania infected cells exhibited strong resistance to apoptosis induced by intrinsic stress or by the activation of cell death receptors. Apoptotic signaling was blocked upstream of mitochondria since Bax translocation, Bax and Bak oligomerisation and cytochrome c release were absent in these cells. Caspases were differentially regulated upon Sn infection. Caspase-3 and -9 were not activated upon Sn infection and apoptosis induction; whereas caspases-8 was activated in Sn infected cells even without apoptosis induction. This indicates that, Sn utilizes death receptor association independent caspase activation for thriving in the host environment. Infected cells turned on pro-survival pathways like cellular Inhibitor of Apoptosis Proteins (IAP-1/2 and XIAP) and the Akt/PI3K pathway. Sn infection also 20 activated the pro-survival transcription factor NF-кB. Blocking any of these survival pathways sensitized the infected host cell towards apoptosis induction, demonstrating their role in infection-induced apoptosis resistance. The NF-кB mutant cells also showed reduced infectivity of Sn, which indicated an essential role of NF-кB in Sn infection. It was interesting to observe that, Acanthamoeba castellanii, a natural host of Sn, survived maintaining its trophozoite forms after infection with Sn upon starvation. The metacaspases, responsible for encystment could be regulated by Sn upon infection. This suggests an early level of gene regulation indicating how the pathogen evolved its ability to inhibit apoptosis in higher organisms. The resistance to apoptosis pathways subverted in Sn-infected cells was similar but not identical to those modulated by Chlamydia. Together, the data supports the hypothesis of evolutionary conserved signaling pathways to apoptosis resistance as common denominators in the order Chlamydiales.}, subject = {Apoptosis}, language = {en} } @phdthesis{Vogel2011, author = {Vogel, Benjamin}, title = {Organisation von Chromatin durch HMGA1 Proteine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65295}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {HMGA1 Proteine sind kleine, basische, Nicht-Histon Proteine, die in L{\"o}sung keine Struktur aufweisen, durch drei AT-Haken, als DNA-Bindungsmotive, gekennzeichnet sind und pr{\"a}ferentiell an die kleine Furche der DNA binden. Als differenziell exprimierte Architekturelemente des Chromatins erf{\"u}llen sie wichtige Funktionen bei der Regulation DNA abh{\"a}ngiger Prozesse in Zellen und w{\"a}hrend Entwicklungsprozessen. Aberrante Expressionen f{\"u}hren zu Entwicklungsdefekten und Krebs. In dieser Arbeit wurde der Einfluss von HMGA1 Proteinen auf die Organisation des Chromatins untersucht. Als Modell diente dabei zun{\"a}chst die Differenzierung von C2C12 Muskelvorl{\"a}uferzellen. Wie in einer fr{\"u}heren Arbeit gezeigt wurde, ist die Herunterregulation von HMGA1a essentiell f{\"u}r den Eintritt von C2C12 Zellen in die Myogenese. Eine konstante {\"U}berexpression von HMGA1a-eGFP hingegen verhindert die Muskeldifferenzierung durch Beeinflussung der Expression myogenesespezifischer Gene und Etablierung einer stabilen Chromatinstruktur. Wie in der vorliegenden Arbeit herausgefunden wurde, nimmt die differenzielle HMGA1a Expression nicht nur Einfluss auf die Expression muskelspezifischer Gene, sondern auch auf die globale Zusammensetzung des Chromatins durch eine reduzierte Expression von H1 Histonen und einer aberranten Expression von HMGB1, HMGN1 und HP1 Proteinen. HMGA1a wurde zusammen mit ORC Proteinen eine Funktion bei der Definition von Replikationsurspr{\"u}ngen in eukaryotischen Zellen zugesprochen. ORC Proteine wurden auch als Komponenten des Heterochromatins und als Interaktionspartner von HP1α identifiziert. Hier konnte mit Hilfe von Co-Immunpr{\"a}zipitationen, Pull-down Assays und Verdr{\"a}ngungsexperimenten gezeigt werden, dass HMGA1 ein weiterer, direkter Interaktionspartner von ORC Proteinen im Heterochromatin ist und zusammen mit HP1α kooperiert. Pull-down-, Verdr{\"a}ngungs- und siRNA-Experimente zeigten zudem, dass HMGA1 zwar nicht direkt mit HP1α interagiert, die Kooperation der Proteine {\"u}ber ORC aber dennoch wichtig f{\"u}r die Aufrechterhaltung der Heterochromatinsstruktur ist. Damit erweisen sich HMGA1 Proteine als wichtige Stabilisierungsfaktoren des Heterochromatins. Bislang ging man davon aus, dass HMGA1 Molek{\"u}le linear, also eindimensional, an ein DNA Molek{\"u}l binden. Das Vorhandensein von drei DNA-Bindungsmotiven und die eher struktur- als sequenzabh{\"a}ngige Bindung an die DNA lassen vermuten, dass HMGA1 Proteine auch gleichzeitig an benachbarte DNA-Str{\"a}nge, also auch dreidimensional, binden k{\"o}nnten. Bekr{\"a}ftigt wurde diese Vermutung durch die Bildung von Chromatinaggregaten in Zellen die HMGA1a-eGFP {\"u}berexprimierten. Dies wurde mittels konfokaler und hochaufl{\"o}sender Mikroskopie (dSTORM) analysiert. Um das Potential einer DNA-Quervernetzung durch HMGA1 Proteine nachzuweisen, wurde eine neue Methode entwickelt. Mit Hilfe eines neuartigen DNA Cross-linking Assays wurde nachgewiesen, dass HMGA1 Proteine in der Lage sind, zwei individuelle DNA Str{\"a}nge zu vernetzen. Zudem wurde eine neue Dom{\"a}ne in HMGA1 entdeckt die maßgeblich zum Cross-linking beitr{\"a}gt. Elektronenmikroskopische Analysen best{\"a}tigten, dass HMGA1 Proteine in der Lage sind Kreuzungen und Schleifen in DNA Molek{\"u}len zu erzeugen. Diese Ergebnisse unterst{\"u}tzen die Vermutung, dass HMGA1 Proteine im Zellkern ein DNA Ger{\"u}st bilden k{\"o}nnen, das Einfluss auf die zelltypische Chromatinorganisation nimmt und dadurch DNA abh{\"a}ngige Prozesse beeinflusst. In wie weit eine HMGA1 induzierte DNA Quervernetzung in vivo zum Beispiel in Chromozentren von C2C12 Zellen oder in Krebszellen, in denen HMGA1 Proteine stark {\"u}berexprimiert sind, eine Rolle spielen, m{\"u}ssen k{\"u}nftige Untersuchungen zeigen. In dieser Arbeit konnte also gezeigt werden, dass HMGA1 Proteine die Chromatinstruktur auf drei Ebenen organisieren k{\"o}nnen: Durch Beeinflussung der Chromatinzusammensetzung durch Ver{\"a}nderung der Expression von Chromatinproteinen, durch Interaktion mit anderen Architekturelementen des Chromatins und durch Organisation eines potentiellen DNA Ger{\"u}sts.}, subject = {Chromatin}, language = {de} } @article{MerzFliednerLehrnbecheretal.1990, author = {Merz, H. and Fliedner, A. and Lehrnbecher, T. and Sebald, Walter and M{\"u}ller-Hermelink, H. K. and Feller, A. C.}, title = {Cytokine expression in B-cell non-Hodgkin lymphomas}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62539}, year = {1990}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{WeigelMeyerSebald1989, author = {Weigel, U. and Meyer, M. and Sebald, Walter}, title = {Mutant proteins of human interleukin 2. Renaturation yield, proliferative activity and receptor binding}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62543}, year = {1989}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{FlueggeFischerGrossetal.1989, author = {Fl{\"u}gge, U. I. and Fischer, K. and Gross, A. and Sebald, Walter and Lottspeich, F. and Eckerskorn, C.}, title = {The triose phosphate-3-phosphoglycerate-phosphate translocator from spinach chloroplasts: nucleotide sequence of a full-length cDNA clone and import of the in vitro synthesized precursor protein into chloroplasts}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62559}, year = {1989}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{KleenePfannerPfalleretal.1987, author = {Kleene, R. and Pfanner, N. and Pfaller, R. and Link, T. A. and Sebald, Walter and Neupert, W. and Tropschug, M.}, title = {Mitochondrial porin of Neurospora crassa: cDNA cloning, in vitro expression and import into mitochondria}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62566}, year = {1987}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{RoemischTropschugSebaldetal.1987, author = {R{\"o}misch, J. and Tropschug, M. and Sebald, Walter and Weiss, H.}, title = {The primary structure of cytochrome c\(_1\) from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62578}, year = {1987}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @phdthesis{Kubisch2012, author = {Kubisch, Alexander}, title = {Range border formation in the light of dispersal evolution}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70639}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Understanding the emergence of species' ranges is one of the most fundamental challenges in ecology. Early on, geographical barriers were identified as obvious natural constraints to the spread of species. However, many range borders occur along gradually changing landscapes, where no sharp barriers are obvious. Mechanistic explanations for this seeming contradiction incorporate environmental gradients that either affect the spatio-temporal variability of conditions or the increasing fragmentation of habitat. Additionally, biological mechanisms like Allee effects (i.e. decreased growth rates at low population sizes or densities), condition-dependent dispersal, and biological interactions with other species have been shown to severely affect the location of range margins. The role of dispersal has been in the focus of many studies dealing with range border formation. Dispersal is known to be highly plastic and evolvable, even over short ecological time-scales. However, only few studies concentrated on the impact of evolving dispersal on range dynamics. This thesis aims at filling this gap. I study the influence of evolving dispersal rates on the persistence of spatially structured populations in environmental gradients and its consequences for the establishment of range borders. More specially I investigate scenarios of range formation in equilibrium, periods of range expansion, and range shifts under global climate change ...}, subject = {Areal}, language = {en} } @article{WeichSebaldSchaireretal.1986, author = {Weich, H. A. and Sebald, Walter and Schairer, H. U. and Hoppe, J.}, title = {The human osteosarcoma cell line U-2 OS expresses a 3.8 kilobase mRNA which codes for the sequence of the PDGF-B chain}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62588}, year = {1986}, abstract = {A cDNA clone of about 2500 basepairswas prepared from the human osteosarcoma cellline U-2 OS by hybridizing with a v-sis probe. Sequence analysis showed that this cDNA contains the coding region for the PDGF-B chain. Here we report that the mitogen secreted by these osteosarcoma cells contains the PDGF-B chain and is probably a homodimer of two B-chains.}, subject = {Biochemie}, language = {en} } @article{SchrammFrauneNaumannetal.2011, author = {Schramm, Sabine and Fraune, Johanna and Naumann, Ronald and Hernandez-Hernandez, Abrahan and H{\"o}{\"o}g, Christer and Cooke, Howard J. and Alsheimer, Manfred and Benavente, Ricardo}, title = {A Novel Mouse Synaptonemal Complex Protein Is Essential for Loading of Central Element Proteins, Recombination, and Fertility}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68895}, year = {2011}, abstract = {The synaptonemal complex (SC) is a proteinaceous, meiosis-specific structure that is highly conserved in evolution. During meiosis, the SC mediates synapsis of homologous chromosomes. It is essential for proper recombination and segregation of homologous chromosomes, and therefore for genome haploidization. Mutations in human SC genes can cause infertility. In order to gain a better understanding of the process of SC assembly in a model system that would be relevant for humans, we are investigating meiosis in mice. Here, we report on a newly identified component of the murine SC, which we named SYCE3. SYCE3 is strongly conserved among mammals and localizes to the central element (CE) of the SC. By generating a Syce3 knockout mouse, we found that SYCE3 is required for fertility in both sexes. Loss of SYCE3 blocks synapsis initiation and results in meiotic arrest. In the absence of SYCE3, initiation of meiotic recombination appears to be normal, but its progression is severely impaired resulting in complete absence of MLH1 foci, which are presumed markers of crossovers in wild-type meiocytes. In the process of SC assembly, SYCE3 is required downstream of transverse filament protein SYCP1, but upstream of the other previously described CE-specific proteins. We conclude that SYCE3 enables chromosome loading of the other CE-specific proteins, which in turn would promote synapsis between homologous chromosomes.}, subject = {Maus}, language = {en} } @article{ArendsSebald1984, author = {Arends, H. and Sebald, Walter}, title = {Nucleotide sequence of the cloned mRNA and gene of the ADP/ATP carrier from Neurospora crassa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62684}, year = {1984}, abstract = {A cDNA complementary to the mRNA of the ADPIATP carrier from Neurospora crassa was identified among ordered cDNA clones by hybridizing total polyadenylated RNA to pools of 96 cDNA recombinant plasmids and subsequent cellfree translation of hybridization-selected mRNA. Further carrier cDNAs were found by colony fdter hybridization at a frequency of 0.2-0.3\%. The gene of the carrier was cloned and isolated on a 4.6-kbp EcoRl fragment of total Neurospora DNA, and the start of the mRNA was determined by Sl nuclease mapping. From the nucleotide sequence of the cDNA and the genomic DNA, the primary structure of the gene, of the mRNA and of the ADP I ATP carrier protein could be deduced. The gene occurs in a single copy in the genome and related genes are absent. It contains two short introns, and a pyrimidine-rieb promoter region. The mRNA has a 46-bp 5 1 end and a 219-bp 3 1 end. There is an open reading frame coding for the 313 amino acid residues of the Neurospora carrier protein. The amino acid sequence is homologous in 148 positions with the established primary structure of the beef heart carrier.}, subject = {Biochemie}, language = {en} }