@phdthesis{Vershenya2010,
  author    = {Vershenya, Stanislav},
  title     = {Quantitative and qualitative analyses of in-paralogs},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51358},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {In our analysis I was interested in the gene duplications, with focus on in-paralogs. In-paralogs are gene duplicates which arose after species split. Here I analysed the in-paralogs quantitatively, as well as qualitatively. For quantitative analysis genomes of 21 species were taken. Most of them have vastly different lifestyles with maximum evolutionary distance between them 1100 million years. Species included mammals, fish, insects and worm, plus some other chordates. All the species were pairwised analysed by the Inparanoid software, and in-paralogs matrix were built representing number of in-paralogs in all vs. all manner. Based on the in-paralogs matrix I tried to reconstruct the evolutionary tree using in-paralog numbers as evolutionary distance. If all 21 species were used the resulting tree was very far from real one: a lot of species were misplaced. However if the number was reduced to 12, all of the species were placed correctly with only difference being wrong insect and fish clusters switched. Then to in-paralogs matrix the neighbour-net algorithm was applied. The resulting "net" tree showed the species with fast or slow duplications rates compared to the others. We could identify species with very high or very low duplications frequencies and it correlates with known occurrences of the whole genome duplications. As the next step I built the graphs for every single species showing the correlation between their in-paralogs number and evolutionary distance. As we have 21 species, graph for every species is built using 20 points. Coordinates of the points are set using the evolutionary distance to that particular species and in-paralogs number. In mammals with increasing the distance from speciation the in-paralogs number also increased, however not in linear fashion. In fish and insects the graph close to zero is just the same in mammals' case. However, after reaching the evolutionary distances more than 800 million years the number of inparalogs is beginning to decrease. We also made a simulation of gene duplications for all 21 species and all the splits according to the fossil and molecular clock data from literature. In our simulation duplication frequency was minimal closer to the past and maximum in the near-present time. Resulting curves had the same shape the experimental data ones. In case of fish and insect for simulation the duplication rate coefficient even had to be set negative in order to repeat experimental curve shape. To the duplication rate coefficient in our simulation contribute 2 criteria: gene duplications and gene losses. As gene duplication is stochastical process it should always be a constant. So the changing in the coefficient should be solely explained by the increasing gene loss of old genes. The processes are explained by the evolution model with high gene duplication and loss ratio. The drop in number of in-paralogs is probably due to the BLAST algorithm. It is observed in comparing highly divergent species and BLAST cannot find the orthologs so precisely anymore. In the second part of my work I concentrated more on the specific function of inparalogs. Because such analysis is time-consuming it could be done on the limited number species. Here I used three insects: Drosophila melanogaster (fruit y), Anopheles gambiae (mosquito) and Apis mellifera (honeybee). After Inparnoid analyses and I listed the cluster of orthologs. Functional analyses of all listed genes were done using GO annotations and also KEGG PATHWAY database. We found, that the gene duplication pattern is unique for each species and that this uniqueness is rejected through the differences in functional classes of duplicated genes. The preferences for some classes reject the evolutionary trends of the last 350 million years and allow assumptions on the role of those genes duplications in the lifestyle of species. Furthermore, the observed gene duplications allowed me to find connections between genomic changes and their phenotypic manifestations. For example I found duplications within carbohydrate metabolism rejecting feed pattern adaptation, within photo- and olfactory-receptors indicating sensing adaptation and within troponin indicating adaptations in the development. Despite these species specific differences, found high correlations between the independently duplicated genes between the species. This might hint for a "pool" of genes preferentially duplicated. Taken together, the observed duplication patterns reject the adaptational process and provide us another link to the field of genomic zoology.},
  subject      = {Duplikation},
  language  = {en}
}
@article{HeisswolfUlmannObermaieretal.2007,
  author    = {Heisswolf, Annette and Ulmann, Sandra and Obermaier, Elisabeth and Mitesser, Oliver and Poethke, Hans J.},
  title     = {Host plant finding in the specialised leaf beetle Cassida canaliculata: an analysis of small-scale movement behaviour},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49485},
  year      = {2007},
  abstract  = {1. Host plant finding in walking herbivorous beetles is still poorly understood. Analysis of small-scale movement patterns under semi-natural conditions can be a useful tool to detect behavioural responses towards host plant cues. 2. In this study, the small-scale movement behaviour of the monophagous leaf beetle Cassida canaliculata Laich. (Coleoptera: Chrysomelidae) was studied in a semi-natural arena (r = 1 m). In three different settings, a host (Salvia pratensis L., Lamiales: Lamiaceae), a non-host (Rumex conglomeratus Murr., Caryophyllales: Polygonaceae), or no plant was presented in the centre of the arena. 3. The beetles showed no differences in the absolute movement variables, straightness and mean walking speed, between the three settings. However, the relative movement variables, mean distance to the centre and mean angular deviation from walking straight to the centre, were significantly smaller when a host plant was offered. Likewise, the angular deviation from walking straight to the centre tended to decline with decreasing distance from the centre. Finally, significantly more beetles were found on the host than on the non-host at the end of all the trials. 4. It is concluded that C. canaliculata is able to recognise its host plant from a distance. Whether olfactory or visual cues (or a combination of both) are used to find the host plant remains to be elucidated by further studies.},
  subject      = {K{\"a}fer},
  language  = {en}
}
@article{BonteLanckackerWiersmaetal.2008,
  author    = {Bonte, Dries and Lanckacker, Kjell and Wiersma, Elisabeth and Lens, Luc},
  title     = {Web building flexibility of an orb-web spider in a heterogeneous agricultural landscape},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48262},
  year      = {2008},
  abstract  = {Abstract: Intensification of land-use in agricultural landscapes is responsible for a decline of biodiversity which provide important ecosystem services like pest-control. Changes in landscape composition may also induce behavioural changes of predators in response to variation in the biotic or abiotic environment. By controlling for environmentally confounding factors, we here demonstrate that the orb web spider Araneus diadematus alters its web building behaviour in response to changes in the composition of agricultural landscapes. Thereby, the species increases its foraging efficiency (i.e. investments in silk and web asymmetry) with an increase of agricultural land-use at intermediate spatial scales. This intensification is also related to a decrease in the abundance of larger prey. A negative effect of landscape properties at similar spatial scales on spider fitness was recorded when controlling for relative investments in capture thread length. This study consequently documents the web building flexibility in response to changes in landscape composition, possibly due to changes in prey availability.},
  language  = {en}
}
@article{LambeetsVandegehuchteMaelfaitetal.2009,
  author    = {Lambeets, Kevin and Vandegehuchte, Martijn L. and Maelfait, Jean-Pierre and Bonte, Dries},
  title     = {Integrating environmental conditions and functional life-history traits for riparian arthropod conservation planning},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-50148},
  year      = {2009},
  abstract  = {River banks are naturally disturbed habitats, in which local flood events and the landscape structure are expected to govern riparian species assemblages. Not solely effects of flooding per se, but also related changes in vegetation structure will affect species' distribution. By elucidating the relationships between species' occurrence and multivariate habitat conditions on a restricted spatial scale, insight into conservation strategies to preserve riparian species is gained. Ordination and grouping methods revealed important environmental and functional trait constraints on species composition of predatory riparian arthropod assemblages. Mainly flooding disturbance appeared to affect spider and carabid beetle species composition. Habitat affinity and dispersal ability were retained as important traits explaining similarity between arthropod assemblages. River banks similar in species composition differed in absolute and functional group species richness. Furthermore, Poisson regressions demonstrated the importance of variation in discharge regime, sediment composition and vegetation structure for the preservation of rare riparian arthropods. Whereas hygrophilic species benefited from increased vegetation cover, xerothermophilic specialists were favoured by increased flooding disturbance. In contrast to flight-active riparian carabids occurring throughout the river system, especially cursorial spiders are expected to go extinct under increased anthropogenic alterations of discharge regimes. We show the importance of a dynamic and evidence-based approach of river management on a local scale to preserve vulnerable riparian arthropods. In general, river restoration should generate the required heterogeneity in environmental conditions (e.g. dynamic processes) at the river bank level, thereby increasing the sustainability of riverine landscapes. More-over, we argue that the understanding of functional responses towards environmental factors results in general and widely applicable guiding concepts for species conservation.},
  subject      = {Laufk{\"a}fer},
  language  = {de}
}
@article{LambeetsVandegehuchteMaelfaitetal.2008,
  author    = {Lambeets, Kevin and Vandegehuchte, Martijn L. and Maelfait, Jean-Pierre and Bonte, Dries},
  title     = {Understanding the impact of flooding on trait-displacements and shifts in assemblage structure of predatory arthropods on river banks},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49580},
  year      = {2008},
  abstract  = {1. Species assemblages of naturally disturbed habitats are governed by the prevailing disturbance regime. Consequently, stochastic flood events affect river banks and the inhabiting biota. Predatory arthropods occupy predominantly river banks in relation to specific habitat conditions. Therefore, species sorting and stochastic processes as induced by flooding are supposed to play important roles in structuring riparian arthropod assemblages in relation to their habitat preference and dispersal ability. 2. To ascertain whether assemblages of spiders and carabid beetles from disturbed river banks are structured by stochastic or sorting mechanisms, diversity patterns and assemblage-wide trait-displacements were assessed based on pitfall sampling data. We tested if flooding disturbance within a lowland river reach affects diversity patterns and trait distribution in both groups. 3. Whereas the number of riparian spider species decreased considerably with increased flooding, carabid beetle diversity benefited from intermediate degrees of flooding. Moreover, regression analyses revealed trait-displacements, reflecting sorting mechanisms particularly for spiders. Increased flooding disturbance was associated with assemblage-wide increases of niche breadth, shading and hygrophilic preference and ballooning propensity for spider (sub)families. Trait patterns were comparable for Bembidiini carabids, but were less univocal for Pterostichini species. Body size decreased for lycosid spiders and Bembidiini carabids with increased flooding, but increased in linyphiid spiders and Pterostichini carabids. 4. Our results indicate that mainly riparian species are disfavoured by either too high or too low degrees of disturbance, whereas eurytopic species benefit from increased flooding. Anthropogenic alterations of flooding disturbance constrain the distribution of common hygrophilous species and/or species with high dispersal ability, inducing shifts towards less specialized arthropod assemblages. River banks with divergent degrees of flooding impact should be maintained throughout dynamic lowland river reaches in order to preserve typical riparian arthropod assemblages.},
  subject      = {Flussufer},
  language  = {en}
}
@article{RandlkoferJordanMitesseretal.2009,
  author    = {Randlkofer, Barbara and Jordan, Florian and Mitesser, Oliver and Meiners, Torsten and Obermaier, Elisabeth},
  title     = {Effect of vegetation density, height, and connectivity on the oviposition pattern of the leaf beetle Galeruca tanaceti},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49665},
  year      = {2009},
  abstract  = {Vegetation structure can profoundly influence patterns of abundance, distribution, and reproduction of herbivorous insects and their susceptibility to natural enemies. The three main structural traits of herbaceous vegetation are density, height, and connectivity. This study determined the herbivore response to each of these three parameters by analysing oviposition patterns in the field and studying the underlying mechanisms in laboratory bioassays. The generalist leaf beetle, Galeruca tanaceti L. (Coleoptera: Chrysomelidae), preferentially deposits its egg clutches on non-host plants such as grasses. Earlier studies revealed that oviposition within structurally complex vegetation reduces the risk of egg parasitism. Consequently, leaf beetle females should prefer patches with dense, tall, or connected vegetation for oviposition in order to increase their reproductive success. In the present study, we tested the following three hypotheses on the effect of stem density, height, and connectivity on oviposition: (1) Within habitats, the number of egg clutches in areas with high stem densities is disproportionately higher than in low-density areas. The number of egg clutches on (2) tall stems or (3) in vegetation with high connectivity is higher than expected for a random distribution. In the field, stem density and height were positively correlated with egg clutch presence. Moreover, a disproportionately high presence of egg clutches was determined in patches with high stem densities. Stem height had a positive influence on oviposition, also in a laboratory two-choice bioassay, whereas stem density and connectivity did not affect oviposition preferences in the laboratory. Therefore, stem height and, potentially, density, but not connectivity, seem to trigger oviposition site selection of the herbivore. This study made evident that certain, but not all traits of the vegetation structure can impose a strong influence on oviposition patterns of herbivorous insects. The results were finally compared with data on the movement patterns of the specialised egg parasitoid of the herbivore in comparable types of vegetation structure.},
  subject      = {Blattk{\"a}fer},
  language  = {en}
}
@phdthesis{Kay2018,
  author    = {Kay, Janina},
  title     = {The circadian clock of the carpenter ant \(Camponotus\) \(floridanus\)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158061},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Due to the earth´s rotation around itself and the sun, rhythmic daily and seasonal changes in illumination, temperature and many other environmental factors occur. Adaptation to these environmental rhythms presents a considerable advantage to survival. Thus, almost all living beings have developed a mechanism to time their behavior in accordance. This mechanism is the endogenous clock. If it fulfills the criteria of (1) entraining to zeitgebers (2) free-running behavior with a period of ~ 24 hours (3) temperature compensation, it is also referred to as "circadian clock". Well-timed behavior is crucial for eusocial insects, which divide their tasks among different behavioral castes and need to respond to changes in the environment quickly and in an orchestrated fashion. Circadian rhythms have thus been studied and observed in many eusocial species, from ants to bees. The underlying mechanism of this clock is a molecular feedback loop that generates rhythmic changes in gene expression and protein levels with a phase length of approximately 24 hours. The properties of this feedback loop are well characterized in many insects, from the fruit fly Drosophila melanogaster, to the honeybee Apis mellifera. Though the basic principles and components of this loop are seem similar at first glance, there are important differences between the Drosophila feedback loop and that of hymenopteran insects, whose loop resembles the mammalian clock loop. The protein PERIOD (PER) is thought to be a part of the negative limb of the hymenopteran clock, partnering with CRYPTOCHROME (CRY). The anatomical location of the clock-related neurons and the PDF-network (a putative in- and output mediator of the clock) is also well characterized in Drosophila, the eusocial honeybee as well as the nocturnal cockroach Leucophea maderae. The circadian behavior, anatomy of the clock and its molecular underpinnings were studied in the carpenter ant Camponotus floridanus, a eusocial insect Locomotor activity recordings in social isolation proved that the majority of ants could entrain to different LD cycles, free-ran in constant darkness and had a temperature-compensated clock with a period slightly shorter than 24 hours. Most individuals proved to be nocturnal, but different types of activity like diurnality, crepuscularity, rhythmic activity during both phases of the LD, or arrhythmicity were also observed. The LD cycle had a slight influence on the distribution of these activities among individuals, with more diurnal ants at shorter light phases. The PDF-network of C. floridanus was revealed with the anti-PDH antibody, and partly resembled that of other eusocial or nocturnal insects. A comparison of minor and major worker brains, only revealed slight differences in the number of somata and fibers crossing the posterior midline. All in all, most PDF-structures that are conserved in other insects where found, with numerous fibers in the optic lobes, a putative accessory medulla, somata located near the proximal medulla and many fibers in the protocerebrum. A putative connection between the mushroom bodies, the optic lobes and the antennal lobes was found, indicating an influence of the clock on olfactory learning. Lastly, the location and intensity of PER-positive cell bodies at different times of a 24 hour day was established with an antibody raised against Apis mellifera PER. Four distinct clusters, which resemble those found in A. mellifera, were detected. The clusters could be grouped in dorsal and lateral neurons, and the PER-levels cycled in all examined clusters with peaks around lights on and lowest levels after lights off. In summary, first data on circadian behavior and the anatomy and workings of the clock of C. floridanus was obtained. Firstly, it´s behavior fulfills all criteria for the presence of a circadian clock. Secondly, the PDF-network is very similar to those of other insects. Lastly, the location of the PER cell bodies seems conserved among hymenoptera. Cycling of PER levels within 24 hours confirms the suspicion of its role in the circadian feedback loop.},
  subject      = {Chronobiologie},
  language  = {en}
}
@phdthesis{Keidel2011,
  author    = {Keidel, Kristina},
  title     = {Charakterisierung des Hfq-Regulons in Bordetella pertussis und Bordetella bronchiseptica},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66677},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Bordetellen sind Gram-negative Kokkobazillen, die phylogenetisch zu den β-Proteobakterien z{\"a}hlen und in der Familie der Alcaligenaceae eingeordnet sind. Der bedeutendste Vertreter der Gattung, die nach heutigem Kenntnisstand neun Arten umfasst, ist Bordetella pertussis, der Erreger des Keuchhustens. Der Keim ist obligat humanpathogen und besitzt zahlreiche Virulenzfaktoren, um die Epithelzellen des Respirationstraktes zu besiedeln und zu zerst{\"o}ren, wodurch es zu dem charakteristischen Krankheitsverlauf kommt. Neben B. pertussis werden noch B. bronchiseptica und B. parapertussis dem sogenannten B. bronchiseptica-Cluster zugeteilt. Alle Vertreter des B. bronchiseptica-Clusters sind in der Lage, bei verschiedenen Wirtsspezies respiratorische Erkrankungen mit unterschiedlichem Schweregrad auszul{\"o}sen. Dabei weist B. bronchiseptica ein breiteres Wirtsspektrum auf und kann Atemwegserkrankungen in einer Vielzahl von S{\"a}ugetieren ausl{\"o}sen, wohingegen B. parapertussis vornehmlich Schafe und Menschen infiziert und bei letzteren eine schw{\"a}chere Form des Keuchhustens bewirkt. Das Hfq-Protein wurde urspr{\"u}nglich als Wirtsfaktor identifiziert, welcher f{\"u}r die Replikation des RNA-Phagen Qβ in Escherichia coli ben{\"o}tigt wird (host factor for Qβ oder HF-1). Es ist in Struktur und Funktion homolog zu den Sm-Proteinen aus Eukaryoten, die am Splicing von mRNAs involviert sind. Die Beteiligung des Hfq-Proteins an regulatorischen Vorg{\"a}ngen, die durch kleine nicht-kodierende RNAs (sRNAs) vermittelt werden, wurde erstmals in einer Studie zum Mechanismus der rpoS-Regulation durch die kleine regulatorische RNA OxyS ersichtlich. Seitdem konnte f{\"u}r eine Vielzahl an sRNAs gezeigt werden, dass sie an Hfq gebunden vorliegen und die Hilfe des Proteins bei der post-transkriptionellen Kontrolle ihrer Ziel-mRNAs ben{\"o}tigen. In dieser Hinsicht {\"u}bernimmt Hfq die Rolle eines RNA-Chaperons, indem es trans-kodierte sRNAs stabilisiert und die Basenpaarung mit ihren Ziel-mRNAs f{\"o}rdert. Dabei beeinflusst die Bindung der sRNA-Regulatoren an ihre Ziel-mRNAs deren Translation, sowohl aktivierend als auch inhibierend. Bislang wurden Hfq-Homologe in der H{\"a}lfte aller sequenzierten Gram-positiven und Gram-negativen Bakterienarten gefunden. Eine BLAST-Analyse ergab, dass B. pertussis und B. bronchiseptica Homologe zum Hfq-Protein aufweisen und diese in der ver{\"o}ffentlichten Genomsequenz bereits als Hfq-Protein annotiert sind. Fokus dieser Arbeit war weitestgehend, die Funktion des Hfq-Proteins in B. pertussis und vergleichend in B. bronchiseptica zu charakterisieren. Mittels Primer Extension-Analyse konnte zun{\"a}chst der Startpunkt des hfq-Transkripts in B. pertussis und B. bronchiseptica unter logarithmischen Wachstumsbedingungen bestimmt werden. Dieser Startpunkt war zudem unter station{\"a}ren Wachstumsbedingungen und nach Hitzestress aktiv, was in Diskrepanz zur Beobachtung in E. coli steht. Ferner konnte festgestellt werden, dass die hfq-Transkription nach Induktion verschiedener Stressformen in beiden Organismen erh{\"o}ht war. Nach Generierung der jeweiligen Δhfq-Mutanten in beiden Organismen wurden diese charakterisiert. Die B. pertussis Δhfq-Mutante zeigte ein deutliches Wachstumsdefizit gegen{\"u}ber dem Wildtyp, im Gegensatz zu B. bronchiseptica Δhfq, die sich im Wachstum wie der Wildtyp verhielt. Beide Mutanten zeigten sich sensitiver gegen{\"u}ber H2O2-Stress als der Wildtyp, nicht jedoch gegen{\"u}ber weiteren oxidativen Stressbedingungen oder Membranstress induzierenden Substanzen. Die Δhfq-Mutante in B. pertussis war zudem in ihrer F{\"a}higkeit zur Biofilmbildung beeintr{\"a}chtigt, was jedoch nicht f{\"u}r B. bronchiseptica Δhfq galt. Da Hfq an sRNA-mRNA-Interaktionen, welche die Translation der mRNAs beeinflussen, beteiligt ist, sollte {\"u}ber 2D-Gelelektrophorese das Hfq-regulierte Proteom in B. pertussis und B. bronchiseptica bestimmt werden. Auff{\"a}llig war, dass viele periplasmatische Transport-bindeproteine von der Δhfq-Mutation betroffen waren. Es zeigten sich aber auch Stoffwechselenzyme und wichtige Housekeeping-Faktoren, wie z. B. der Elongationsfaktor EF-Tu und das Chaperon GroEL, in der Δhfq-Mutante dereguliert. Generell scheint das Hfq-regulierte Proteom in B. pertussis und B. bronchiseptica nur einen kleinen Teil des gesamten Proteoms auszumachen. Zudem ist das Hfq-regulierte Proteom variabel zwischen verschiedenen Wachstumsbedingungen, aber auch zwischen den beiden Organismen trotz der engen Verwandtschaft. Die Expression ausgew{\"a}hlter Virulenzfaktoren zeigte keinen Unterschied zwischen Δhfq-Mutante und B. pertussis-Wildtyp.},
  subject      = {Bordetella pertussis},
  language  = {de}
}
@phdthesis{Mishra2011,
  author    = {Mishra, Dushyant},
  title     = {The content of olfactory memory in larval Drosophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66316},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {An animal depends heavily on its sense of smell and its ability to form olfactory associations as this is crucial for its survival. This thesis studies in two parts about such associative olfactory learning in larval Drosophila. The first part deals with different aspects of odour processing while the second part is concerned with aspects related to memory and learning. Chapter I.1 highlights how odour intensities could be integrated into the olfactory percept of larval Drosophila. I first describe the dose-effect curves of learnability across odour intensities for different odours and then choose odour intensities from these curves such that larvae are trained at intermediate odour intensity, but are tested for retention with either that trained intermediate odour intensity, or with respectively HIGHer or LOWer intensities. I observe a specificity of retention for the trained intensity for all the odours used. Further I compare these findings with the case of adult Drosophila and propose a circuit level model of how such intensity coding comes about. Such intensity specificity of learning adds to appreciate the richness in 'content' of olfactory memory traces, and to define the demands on computational models of olfaction and olfactory learning. Chapter I.2 provides a behaviour-based estimate of odour similarity using four different types of experiments to yield a combined, task-independent estimate of perceived difference between odour-pairs. Further comparison of these perceived differences to published measures of physico- chemical difference reveals a weak correlation. Notable exceptions to this correlation are 3-octanol and benzaldehyde. Chapter I.3 shows for two odours (3-octanol and 1-octene-3-ol) that perceptual differences between these odours can either be ignored after non-discriminative training (generalization), or accentuated by odour-specific reinforcement (discrimination). Anosmic Or83b1 mutants have lost these faculties, indicating that this adaptive adjustment is taking place downstream of Or83b expressing sensory neurons. Chapter II.1 of this thesis deals with food supplementation with dried roots of Rhodiola rosea. This dose-dependently improves odour- reward associative function in larval Drosophila. Supplementing fly food with commercially available tablets or extracts, however, does not have a 'cognitive enhancing' effect, potentially enabling us to differentiate between the effective substances in the root versus these preparations. Thus Drosophila as a genetically tractable study case should now allow accelerated analyses of the molecular mechanism(s) that underlie this 'cognitive enhancement' conveyed by Rhodiola rosea. Chapter II.2 describes the role of Synapsin, an evolutionarily conserved presynaptic phosphoprotein using a combined behavioural and genetic approach and asks where and how, this protein affects functions in associative plasticity of larval Drosophila. This study shows that a Synapsin-dependent memory trace can be pinpointed to the mushroom bodies, a 'cortical' brain region of the insects. On the molecular level, data in this study assign Synapsin as a behaviourally- relevant effector of the AC-cAMP-PKA cascade.},
  subject      = {Drosophila},
  language  = {en}
}
@phdthesis{Schmitt2010,
  author    = {Schmitt, Kathrin},
  title     = {Identification and Characterization of GAS2L3 as a Novel Mitotic Regulator in Human Cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-52704},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Precise control of mitotic progression is vital for the maintenance of genomic integrity. Since the loss of genomic integrity is known to promote tumorigenesis, the identification of knew G2/M regulatory genes attracts great attention. LINC, a human multiprotein complex, is a transcriptional activator of a set of G2/M specific genes. By depleting LIN9 in MEFs, a core subunit of LINC, Gas2l3 was identified as a novel LINC target gene. The so far uncharacterized Gas2l3 gene encodes for a member of the family of growth arrest specific 2 (GAS2) proteins, which share a highly conserved putative actin binding CH and a putative microtubule binding GAS2 domain. In the present study GAS2L3 was identified as a LINC target gene also in human cells. Gene expression analysis revealed that GAS2L3 transcription, in contrast to all other GAS2 family members, is highly regulated during the cell cycle with highest expression in G2/M. The GAS2L3 protein showed a specific localization pattern during the M phase: In metaphase, GAS2L3 localized to the mitotic spindle, relocated to the spindle midzone microtubules in late anaphase and concentrated at the midbody in telophase where it persisted until the end of cytokinesis. Overexpression of a set of different GAS2L3 deletion mutants demonstrated that the localization to the mitotic microtubule network is dependent on the C-terminus, whereas the midbody localization is dependent on full length GAS2L3 protein. Additionally, exclusive overexpression of the CH domain induced the formation of actin stress fibers, suggesting that the CH domain is an actin binding domain. In contrast, the GAS2 domain was neither needed nor sufficient for microtubule binding, indicating that there must be an additional so far unknown microtubule binding domain in the C-terminus. Interestingly, immunoblot analysis also identified the C-terminus as the domain responsible for GAS2L3 protein instability, partially dependent on proteasomal degradation. Consistent with its specific localization pattern, GAS2L3 depletion by RNAi demonstrated its responsibility for proper mitosis and cytokinesis. GAS2L3 depletion in HeLa cells resulted in the accumulation of multinucleated cells, an indicator for chromosome mis-segregation during mitosis. Also the amount of cells in cytokinesis was enriched, indicating failures in completing the last step of cytokinesis, the abscission. Strikingly, treatment with microtubule poisons that lead to the activation of the spindle assembly checkpoint (SAC) indicated that the SAC was weakened in GAS2L3 depleted cells. Although the exact molecular mechanism is still unknown, fist experiments support the hypothesis that GAS2L3 might be a regulator of the SAC master kinase BUBR1. In conclusion, this study provides first evidence for GAS2L3 as a novel regulator of mitosis and cytokinesis and it might therefore be an important guardian against tumorigenesis.},
  subject      = {Mensch},
  language  = {en}
}
@phdthesis{Duraphe2010,
  author    = {Duraphe, Prashant},
  title     = {Identification and characterization of AUM, a novel human tyrosine phosphatase},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-44256},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Protein Phosphatasen werden aufgrund der Aminos{\"a}uresequenzen ihrer aktiven Zentren in drei große Familien unterteilt. In einer neu entdeckten Familie von Phosphatasen ist das aktive Zentrum durch die Sequenz DXDX(T/V) charakterisiert. Diese Aspartat-abh{\"a}ngigen Phosphatasen geh{\"o}ren zu der Superfamilie der Hydrolasen vom Haloazid Dehalogenase(HAD)-Typ, einer evolution{\"a}r konservierten und ubiquit{\"a}r verbreiteten Enzymfamilie. Bislang konnten 58 menschliche HAD Enzyme durch Datenbankanalysen identifiziert werden. Ihre Funktionen sind jedoch nach wie vor nur rudiment{\"a}r verstanden. Im Rahmen dieser Arbeit wurde zun{\"a}chst das Komplement aller menschlichen HAD Phosphatasen durch Datenbank-Recherchen erfasst. Zusammen mit phylogenetischen Analysen gelang es, eine zum damaligen Zeitpunkt unbekannte, putative Phosphatase zu identifizieren, die eine vergleichsweise hohe Sequenz-Homologie zu der Zytoskelettregulierenden HAD Phosphatase Chronophin aufweist. Dieses neuartige Enzym wurde kloniert und mit biochemischen und zellbiologischen Methoden charakterisiert. Auf der Basis dieser Befunde bezeichnen wir dieses neuartige Protein als AUM (actin remodeling, ubiquitously expressed, magnesium-dependent HAD phosphatase).Mittels Northern blot, real-time PCR und Western blot Analysen konnte gezeigt werden, dass AUM in allen untersuchten menschlichen und murinen Geweben exprimiert wird. Die h{\"o}chste Expression konnte in Hodengewebe nachgewiesen werden. Durch immunohistochemische Untersuchungen konnte gezeigt werden, dass AUM spezifisch in reifenden Keimzellen mit einem Expressionsmaximum zum Zeitpunkt der Spermiogenese exprimiert wird. Um die Substratpr{\"a}ferenz von AUM zu charakterisieren, wurde zun{\"a}chst ein peptidbasierter in vitro Phosphatase-Substrat-Screen durchgef{\"u}hrt. Hierbei wurden 720 aus menschlichen Phosphoproteinen abgeleitete Phosphopeptide untersucht. Interessanterweise dephosphorylierte AUM ausschließlich Phosphotyrosin (pTyr)-enthaltende Peptide. Nur 17 pTyr-Peptide (~2\% aller untersuchten Peptide) fungierten als AUM-Substrate. Diese Daten legen eine hohe Substratspezifit{\"a}t von AUM nahe. Zu den putativen AUM Substraten geh{\"o}ren Proteine, die in die Dynamik der Zytoskelett-Reorganisation sowie in Tyrosin Kinasevermittelte Signalwege eingebunden sind. In {\"U}bereinstimmung mit den Ergebnissen dieses Phosphopeptid-Screens konnte mittels Phosphatase overlay assays sowie in Zellextrakten aus Pervanadat-behandelten HeLa Zellen demonstriert werden, dass AUM eine begrenzte Anzahl Tyrosin-phosphorylierter Proteinen dephosphorylieren kann.In zellul{\"a}ren Untersuchungen wurde die m{\"o}gliche Rolle von AUM im Rahmen der durch den epidermalen Wachstumsfaktor (EGF) ausgel{\"o}sten Tyrosin-Phosphorylierung in einer Spermatogonien Zelllinie (GC-1 spg-Zellen) analysiert. So konnte nachgewiesen werden, dass die {\"U}berexpression von AUM zu einer moderaten Abnahme Tyrosin phosphorylierter Proteine nach EGF-Stimulation f{\"u}hrte. Im Gegensatz dazu l{\"o}ste jedoch die durch RNAInterferenz vermittelte Depletion von endogenem AUM einen robusten Anstieg Tyrosinphosphorylierter Proteine aus, zu denen auch der EGF-Rezeptor selbst z{\"a}hlt. Zus{\"a}tzlich zu dem EGF-Rezeptor wurde die Src-Kinase im Zuge des Phosphopeptid- Screens als m{\"o}gliches AUM Substrat identifiziert. Daher wurden in vitro Kinase/Phosphatase-Assays mit gereinigtem Src und AUM durchgef{\"u}hrt. Mit diesem Ansatz konnte erstmals gezeigt werden, dass AUM in der Lage ist, die Src-Kinase zu aktivieren, w{\"a}hrend Src AUM phosphoryliert und die AUM Phosphatase-Aktivit{\"a}t blockiert. Diese Ergebnisse deuten auf eine gekoppelte, wechselseitige Regulation von AUM und Src hin. Obwohl die Details dieser Regulation derzeit noch unklar sind, zeigen unsere initialen Ergebnisse, dass AUM die Src-Aktivit{\"a}t unabh{\"a}ngig von seiner Phosphatase Aktivit{\"a}t steigert, w{\"a}hrend Src die AUM Phosphatase-Aktivit{\"a}t Kinase-abh{\"a}ngig vermindert. Auf zellul{\"a}rer Ebene sind AUM-depletierte Zellen durch Ver{\"a}nderungen der Aktin- Zytoskelett-Dynamik und der Zelladh{\"a}sion charakterisiert. So weisen AUM-defiziente Zellen stabilisierte Aktin Streßfasern und vergr{\"o}ßerte fokale Adh{\"a}sionen auf. Weiterhin sind AUMdepletierte Zellen durch ein beschleunigtes spreading auf Fibronektin gekennzeichnet. Wir haben mit AUM ein bisher nicht beschriebenes Mitglied der Familie Aspartat-abh{\"a}ngiger Phosphatasen entdeckt. In dieser Arbeit ist es gelungen, AUM phylogenetisch, biochemisch und zellbiologisch zu charakterisieren. Unsere Ergebnisse legen nahe, dass AUM einen wichtigen, neuartigen Regulator der Src-vermittelten Zytoskelett-Dynamik im Rahmen der Zelladh{\"a}sion und Migration darstellt.},
  subject      = {Tyrosin},
  language  = {en}
}
@phdthesis{Halder2011,
  author    = {Halder, Partho},
  title     = {Identification and characterization of synaptic proteins of Drosophila melanogaster using monoclonal antibodies of the Wuerzburg Hybridoma Library},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67325},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {For a large fraction of the proteins expressed in the human brain only the primary structure is known from the genome project. Proteins conserved in evolution can be studied in genetic models such as Drosophila. In this doctoral thesis monoclonal antibodies (mAbs) from the Wuerzburg Hybridoma library are produced and characterized with the aim to identify the target antigen. The mAb ab52 was found to be an IgM which recognized a cytosolic protein of Mr ~110 kDa on Western blots. The antigen was resolved by two-dimensional gel electrophoresis (2DE) as a single distinct spot. Mass spectrometric analysis of this spot revealed EPS-15 (epidermal growth factor receptor pathway substrate clone 15) to be a strong candidate. Another mAb from the library, aa2, was already found to recognize EPS-15, and comparison of the signal of both mAbs on Western blots of 1D and 2D electrophoretic separations revealed similar patterns, hence indicating that both antigens could represent the same protein. Finally absence of the wild-type signal in homozygous Eps15 mutants in a Western blot with ab52 confirmed the ab52 antigen to be EPS-15. Thus both the mAbs aa2 and ab52 recognize the Drosophila homologue of EPS-15. The mAb aa2, being an IgG, is more suitable for applications like immunoprecipitation (IP). It has already been submitted to the Developmental Studies Hybridoma Bank (DSHB) to be easily available for the entire research community. The mAb na21 was also found to be an IgM. It recognizes a membrane associated antigen of Mr ~10 kDa on Western blots. Due to the membrane associated nature of the protein, it was not possible to resolve it by 2DE and due to the IgM nature of the mAb it was not possible to enrich the antigen by IP. Preliminary attempts to biochemically purify the endogenously expressed protein from the tissue, gave promising results but could not be completed due to lack of time. Thus biochemical purification of the protein seems possible in order to facilitate its identification by mass spectrometry. Several other mAbs were studied for their staining pattern on cryosections and whole mounts of Drosophila brains. However, many of these mAbs stained very few structures in the brain, which indicated that only a very limited amount of protein would be available as starting material. Because these antibodies did not produce signals on Western blots, which made it impossible to enrich the antigens by electrophoretic methods, we did not attempt their purification. However, the specific localization of these proteins makes them highly interesting and calls for their further characterization, as they may play a highly specialized role in the development and/or function of the neural circuits they are present in. The purification and identification of such low expression proteins would need novel methods of enrichment of the stained structures.},
  subject      = {Taufliege},
  language  = {en}
}
@phdthesis{Keller2010,
  author    = {Keller, Alexander},
  title     = {Secondary (and tertiary) structure of the ITS2 and its application for phylogenetic tree reconstructions and species identification},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-56151},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Biodiversity may be investigated and explored by the means of genetic sequence information and molecular phylogenetics. Yet, with ribosomal genes, information for phylogenetic studies may not only be retained from the primary sequence, but also from the secondary structure. Software that is able to cope with two dimensional data and designed to answer taxonomic questions has been recently developed and published as a new scientific pipeline. This thesis is concerned with expanding this pipeline by a tool that facialiates the annotation of a ribosomal region, namely the ITS2. We were also able to show that this states a crucial step for secondary structure phylogenetics and for data allocation of the ITS2-database. This resulting freely available tool determines high quality annotations. In a further study, the complete phylogenetic pipeline has been evaluated on a theoretical basis in a comprehensive simulation study. We were able to show that both, the accuracy and the robustness of phylogenetic trees are largely improved by the approach. The second major part of this thesis concentrates on case studies that applied this pipeline to resolve questions in taxonomy and ecology. We were able to determine several independent phylogenies within the green algae that further corroborate the idea that secondary structures improve the obtainable phylogenetic signal, but now from a biological perspective. This approach was applicable in studies on the species and genus level, but due to the conservation of the secondary structure also for investigations on the deeper level of taxonomy. An additional case study with blue butterflies indicates that this approach is not restricted to plants, but may also be used for metazoan phylogenies. The importance of high quality phylogenetic trees is indicated by two ecological studies that have been conducted. By integrating secondary structure phylogenetics, we were able to answer questions about the evolution of ant-plant interactions and of communities of bacteria residing on different plant tissues. Finally, we speculate how phylogenetic methods with RNA may be further enhanced by integration of the third dimension. This has been a speculative idea that was supplemented with a small phylogenetic example, however it shows that the great potential of structural phylogenetics has not been fully exploited yet. Altogether, this thesis comprises aspects of several different biological disciplines, which are evolutionary biology and biodiversity research, community and invasion ecology as well as molecular and structural biology. Further, it is complemented by statistical approaches and development of informatical software. All these different research areas are combined by the means of bioinformatics as the central connective link into one comprehensive thesis.},
  subject      = {Phylogenie},
  language  = {en}
}
@article{VainshteinSanchezBrazmaetal.2010,
  author    = {Vainshtein, Yevhen and Sanchez, Mayka and Brazma, Alvis and Hentze, Matthias W. and Dandekar, Thomas and Muckenthaler, Martina U.},
  title     = {The IronChip evaluation package: a package of perl modules for robust analysis of custom microarrays},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67869},
  year      = {2010},
  abstract  = {Background: Gene expression studies greatly contribute to our understanding of complex relationships in gene regulatory networks. However, the complexity of array design, production and manipulations are limiting factors, affecting data quality. The use of customized DNA microarrays improves overall data quality in many situations, however, only if for these specifically designed microarrays analysis tools are available. Results: The IronChip Evaluation Package (ICEP) is a collection of Perl utilities and an easy to use data evaluation pipeline for the analysis of microarray data with a focus on data quality of custom-designed microarrays. The package has been developed for the statistical and bioinformatical analysis of the custom cDNA microarray IronChip but can be easily adapted for other cDNA or oligonucleotide-based designed microarray platforms. ICEP uses decision tree-based algorithms to assign quality flags and performs robust analysis based on chip design properties regarding multiple repetitions, ratio cut-off, background and negative controls. Conclusions: ICEP is a stand-alone Windows application to obtain optimal data quality from custom-designed microarrays and is freely available here (see "Additional Files" section) and at: http://www.alice-dsl.net/evgeniy. vainshtein/ICEP/},
  subject      = {Microarray},
  language  = {en}
}
@article{TeutschbeinHaydnSamansetal.2010,
  author    = {Teutschbein, Janka and Haydn, Johannes M. and Samans, Birgit and Krause, Michael and Eilers, Martin and Schartl, Manfred and Meierjohann, Svenja},
  title     = {Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67900},
  year      = {2010},
  abstract  = {Background: Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods: Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results: Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion: Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development. Specifically, a role of FOSL1 in melanomagenic processes is demonstrated. These data are the basis for future detailed analyses of the investigated target genes.},
  language  = {en}
}
@article{BrocherVogelHock2010,
  author    = {Brocher, Jan and Vogel, Benjamin and Hock, Robert},
  title     = {HMGA1 down-regulation is crucial for chromatin composition and a gene expression profile permitting myogenic differentiation},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67914},
  year      = {2010},
  abstract  = {Background: High mobility group A (HMGA) proteins regulate gene transcription through architectural modulation of chromatin and the formation of multi-protein complexes on promoter/enhancer regions. Differential expression of HMGA variants has been found to be important for distinct differentiation processes and deregulated expression was linked to several disorders. Here we used mouse C2C12 myoblasts and C2C12 cells stably over-expressing HMGA1a-eGFP to study the impact of deregulated HMGA1 expression levels on cellular differentiation. Results: We found that induction of the myogenic or osteogenic program of C2C12 cells caused an immediate down-regulation of HMGA1. In contrast to wild type C2C12 cells, an engineered cell line with stable overexpression of HMGA1a-eGFP failed to differentiate into myotubes. Immunolocalization studies demonstrated that sustained HMGA1a-eGFP expression prevented myotube formation and chromatin reorganization that normally accompanies differentiation. Western Blot analyses showed that elevated HMGA1a-eGFP levels affected chromatin composition through either down-regulation of histone H1 or premature expression of MeCP2. RT-PCR analyses further revealed that sustained HMGA1a expression also affected myogenic gene expression and caused either down-regulation of genes such as MyoD, myogenin, Igf1, Igf2, Igfbp1-3 or up-regulation of the transcriptional repressor Msx1. Interestingly, siRNA experiments demonstrated that knock-down of HMGA1a was required and sufficient to reactivate the myogenic program in induced HMGA1a over-expressing cells. Conclusions: Our data demonstrate that HMGA1 down-regulation after induction is required to initiate the myogenic program in C2C12 cells. Sustained HMGA1a expression after induction prevents expression of key myogenic factors. This may be due to specific gene regulation and/or global effects on chromatin. Our data further corroborate that altered HMGA1 levels influence the expression of other chromatin proteins. Thus, HMGA1 is able to establish a specific chromatin composition. This work contributes to the understanding of how differential HMGA1 expression is involved in chromatin organization during cellular differentiation processes and it may help to comprehend effects of HMGA1 over-expression occurring in malign or benign tumours.},
  subject      = {HMG-Proteine},
  language  = {en}
}
@article{LaisneyBraaschWalteretal.2010,
  author    = {Laisney, Juliette A. G. C. and Braasch, Ingo and Walter, Ronald B. and Meierjohann, Svenja and Schartl, Manfred},
  title     = {Lineage-specific co-evolution of the Egf receptor/ligand signaling system},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67922},
  year      = {2010},
  abstract  = {Background: The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. Results: We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Conclusions: Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed with different subsets of Egfr ligands. This fish-specific occurrence of Egf receptor specialization offers unique opportunities to study the functions of different Egf receptor-ligand combinations and their biological outputs in vertebrates. Furthermore, our results strongly support the use of homologous ligands in future studies, as sufficient cross-specificity is very unlikely for this ligand/receptor system.},
  subject      = {Epidermaler Wachstumsfaktor-Rezeptor},
  language  = {en}
}
@article{FriedrichRahmannWeigeletal.2010,
  author    = {Friedrich, Torben and Rahmann, Sven and Weigel, Wilfried and Rabsch, Wolfgang and Fruth, Angelika and Ron, Eliora and Gunzer, Florian and Dandekar, Thomas and Hacker, Joerg and Mueller, Tobias and Dobrindt, Ulrich},
  title     = {High-throughput microarray technology in diagnostics of enterobacteria based on genome-wide probe selection and regression analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67936},
  year      = {2010},
  abstract  = {The Enterobacteriaceae comprise a large number of clinically relevant species with several individual subspecies. Overlapping virulence-associated gene pools and the high overall genome plasticity often interferes with correct enterobacterial strain typing and risk assessment. Array technology offers a fast, reproducible and standardisable means for bacterial typing and thus provides many advantages for bacterial diagnostics, risk assessment and surveillance. The development of highly discriminative broad-range microbial diagnostic microarrays remains a challenge, because of marked genome plasticity of many bacterial pathogens. Results: We developed a DNA microarray for strain typing and detection of major antimicrobial resistance genes of clinically relevant enterobacteria. For this purpose, we applied a global genome-wide probe selection strategy on 32 available complete enterobacterial genomes combined with a regression model for pathogen classification. The discriminative power of the probe set was further tested in silico on 15 additional complete enterobacterial genome sequences. DNA microarrays based on the selected probes were used to type 92 clinical enterobacterial isolates. Phenotypic tests confirmed the array-based typing results and corroborate that the selected probes allowed correct typing and prediction of major antibiotic resistances of clinically relevant Enterobacteriaceae, including the subspecies level, e.g. the reliable distinction of different E. coli pathotypes. Conclusions: Our results demonstrate that the global probe selection approach based on longest common factor statistics as well as the design of a DNA microarray with a restricted set of discriminative probes enables robust discrimination of different enterobacterial variants and represents a proof of concept that can be adopted for diagnostics of a wide range of microbial pathogens. Our approach circumvents misclassifications arising from the application of virulence markers, which are highly affected by horizontal gene transfer. Moreover, a broad range of pathogens have been covered by an efficient probe set size enabling the design of high-throughput diagnostics.},
  subject      = {Mikroarray},
  language  = {en}
}
@phdthesis{Kapustjansky2011,
  author    = {Kapustjansky, Alexander},
  title     = {In vivo imaging and optogenetic approach to study the formation of olfactory memory and locomotor behaviour in Drosophila melanogaster},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69535},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Understanding of complex interactions and events in a nervous system, leading from the molecular level up to certain behavioural patterns calls for interdisciplinary interactions of various research areas. The goal of the presented work is to achieve such an interdisciplinary approach to study and manipulate animal behaviour and its underlying mechanisms. Optical in vivo imaging is a new constantly evolving method, allowing one to study not only the local but also wide reaching activity in the nervous system. Due to ease of its genetic accessibility Drosophila melanogaster represents an extraordinary experimental organism to utilize not only imaging but also various optogenetic techniques to study the neuronal underpinnings of behaviour. In this study four genetically encoded sensors were used to investigate the temporal dynamics of cAMP concentration changes in the horizontal lobes of the mushroom body, a brain area important for learning and memory, in response to various physiological and pharmacological stimuli. Several transgenic lines with various genomic insertion sites for the sensor constructs Epac1, Epac2, Epac2K390E and HCN2 were screened for the best signal quality, one line was selected for further experiments. The in vivo functionality of the sensor was assessed via pharmacological application of 8-bromo-cAMP as well as Forskolin, a substance stimulating cAMP producing adenylyl cyclases. This was followed by recording of the cAMP dynamics in response to the application of dopamine and octopamine, as well as to the presentation of electric shock, odorants or a simulated olfactory signal, induced by acetylcholine application to the observed brain area. In addition the interaction between the shock and the simulated olfactory signal by simultaneous presentation of both stimuli was studied. Preliminary results are supporting a coincidence detection mechanism at the level of the adenylyl cyclase as postulated by the present model for classical olfactory conditioning. In a second series of experiments an effort was made to selecticvely activate a subset of neurons via the optogenetic tool Channelrhodopsin (ChR2). This was achieved by recording the behaviour of the fly in a walking ball paradigm. A new method was developed to analyse the walking behaviour of the animal whose brain was made optically accessible via a dissection technique, as used for imaging, thus allowing one to target selected brain areas. Using the Gal4-UAS system the protocerebral bridge, a substructure of the central complex, was highlighted by expressing the ChR2 tagged by fluorescent protein EYFP. First behavioural recordings of such specially prepared animals were made. Lastly a new experimental paradigm for single animal conditioning was developed (Shock Box). Its design is based on the established Heat Box paradigm, however in addition to spatial and operant conditioning available in the Heat Box, the design of the new paradigm allows one to set up experiments to study classical and semioperant olfactory conditioning, as well as semioperant place learning and operant no idleness experiments. First experiments involving place learning were successfully performed in the new apparatus.},
  subject      = {Taufliege},
  language  = {en}
}
@article{MuellerDieckmannSebaldetal.1994,
  author    = {M{\"u}ller, T. and Dieckmann, T. and Sebald, Walter and Oschkinat, H.},
  title     = {Aspects of receptor binding and signalling of interleukin-4 investigated by site-directed mutagenesis and NMR spectroscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62444},
  year      = {1994},
  abstract  = {Cytokines are hormones that carry information from ceJI to ceH. This information is read from their surface upon binding to transmembrane receptors and by the subsequent initiation of receptor oligomerization. An inftuence on this process through mutagenesis on the hormone surface is highly desirab)e for medical reasons. However, an understanding of hormone-receptor interactions requires insight into the structural changes introduced by the mutations. In this line structural studies on human TL-4 and the medically important IL-4 antagonists YI24D and Y124G are presented. The site a.round YI24 is an important epitope responsible for the a.bility of 11-4 t.o ca.use a signal in the target cells. It is shown that the local main-chain structure around residue 124 in the variants remains unchanged. A strategy is presented here which allows the study of these types of proteins and their variants by NMR which does not require carbon Iabeiied sa.mples.},
  subject      = {Biochemie},
  language  = {en}
}
@article{KruseShenArnoldetal.1993,
  author    = {Kruse, N. and Shen, B. J. and Arnold, S. and Tony, H. P. and M{\"u}ller, T. and Sebald, Walter},
  title     = {Two distinct functional sites of human interleukin 4 are identified by variants impaired in either receptor binding or receptor activation},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62451},
  year      = {1993},
  abstract  = {Interleukin 4 (IL-4) exerts a decisive role in the coord.ination of proteelive immune responses against parasites, particularly helminths. A disregulation of ll.r4 function is possibly involved in the genesis of allergic disease states. The search for important amino acid residues in human ll.r4 by mutational analysis of charged invariant amino acid positions identified two distinct functional sites in the 4-helix-bundle protein. Site 1 was marked by amino acid substitutions of the glutamic acid at position 9 in helix A and arginine at position 88 in helix C. Exchanges at both positions led to IL-4 variants deficient in binding to the extracellular domain of the ll.r4 receptor (IL-4ReJ. In parallel, up to 1000-fold increased concentrations of this type of variant were required to induce T -cell proliferation and B-eeil CD23 expression. Site 2 was marked by amino acid exchanges in helix D at positions 121, 124 and 125 (arginine, tyrosine and serine respectively in the wild-type).ß.A variants affected at site 2 exhibited partial agonist activity during T -cell proliferation; however, they still bound with high affinity to IL-4Rex. [The generation of an IL-4 antagonist by replacing tyrosine 124 with aspartic acid has been described before by Kruse et al. (1992) (EMBO }., 11, 3237-3244)]. These findings indicate that IL-4 functions by bind.ing IL-4Rex via site 1 which is constituted by residues on helices A and C. They further suggest that the association of a second, still undetined receptor protein with site 2 in helix D activates the receptor system and generates a transmembrane signal.},
  subject      = {Biochemie},
  language  = {en}
}
@article{KruseTonySebald1992,
  author    = {Kruse, N. and Tony, H. P. and Sebald, Walter},
  title     = {Conversion of human interleukin-4 into a high affinity antagonist by a single amino acid replacement},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62469},
  year      = {1992},
  abstract  = {lnterleukin-4 (IL-4) represents a prototypic lymphokine (for a recent review see Paul, 1991). It promotes differentiation of B-cells and the proliferation of T- and B-cell, and other cell types of the lymphoid system. An antagonist of human IL-4 was discovered during the studies presented here after Tyr124 of the recombinant proteinbad been substituted by an aspartic acid residue. This IL-4 variant, Y124D, bound with high affinity to the IL-4 receptor (K\(_D\) = 310 pM), but retained no detectable proliferative activity for T -<:ells and inhibited IL-4-dependent T -cell proliferation competitively (K\(_i\) = 620 pM). The loss of efficacy in variant Y124D was estimated to be > 100-fold on the basis of a weak partial agonist activity for the very sensitive induction of CD23 positive B-cells. The subsitution of Tyr124 by either phenylalanine, histidine, asparagine, Iysine or glycine resulted in partial agonist variants with unaltered receptor binding atTmity and relatively small deficiencies in efficacy. These results demoostrate that high affinity binding and signal generation can be uncoupled efticiently in a Iigand of a receptor betonging to the recently identified hematopoietin receptor family. In addition we show for the first time, that a powerful antagonist acting on the IL-4 receptor system can be derived from the IL-4 protein.},
  subject      = {Biochemie},
  language  = {en}
}
@article{LehrnbecherMerzSebaldetal.1991,
  author    = {Lehrnbecher, T. and Merz, H. and Sebald, Walter and Poot, M.},
  title     = {Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62491},
  year      = {1991},
  abstract  = {Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.},
  subject      = {Biochemie},
  language  = {en}
}
@phdthesis{Batzilla2011,
  author    = {Batzilla, Julia},
  title     = {Complete genome sequence of Yersinia enterocolitica subspecies palearctica serotype O:3: Identification of novel virulence-associated genes and evolutionary aspects},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69668},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Yersinia enterocolitica subsp. palearctica Serobiotyp O:3/4 ist verantwortlich f{\"u}r 80-90 \% aller Yersiniosen beim Menschen in Deutschland und Europa. Y. enterocolitica Infektionen zeigen vielf{\"a}ltige Krankheitsbilder wie Gastroenteritis, Lymphadenitis und verschiedene Sp{\"a}tkomplikationen wie reaktive Arthritis. Das wichtigste Tierreservoir stellt das Hausschwein dar. Rohes Schweinefleisch in Metzgereien in Deutschland und anderen Regionen in Nord-Ost Europa ist h{\"a}ufig mit Yersinien kontaminiert (Bayern: 25 \%). Da sich Serobiotyp O:3/4-St{\"a}mme geografisch und phylogenetisch deutlich von dem bisher sequenzierten Serobiotyp O:8/1B Stamm 8081 unterscheiden, wurde eine komplette Genomsequenzierung des europ{\"a}ischen Serobiotyp O:3/4 DSMZ Referenzstammes Y11 (aus Patientenstuhl isoliert) durchgef{\"u}hrt. Um einen genaueren Einblick in die Y. enterocolitica subsp. palearctica Gruppe zu erhalten, wurden zus{\"a}tzlich zwei weitere Serobiotyp O:3/4 Isolate (Stamm Y8265, Patientenisolat, und Stamm Y5307, mit reaktiver Arthritis assoziiertes Patientenisolat), sowie ein eng verwandtes Y. enterocolitica subsp. palearctica Serobiotyp O:5,27/3 Isolat, Stamm Y527P, und zwei Biotyp 1A Isolate (ein Isolat nosokomialer Herkunft (Serogruppe O:5) und ein Umwelt-Isolat (O:36)) unvollst{\"a}ndig sequenziert. Die nicht mausvirulenten St{\"a}mme wurden mit dem mausvirulenten Y. enterocolitica subsp. enterocolitica Serobiotyp O:8/1B Stamm 8081 verglichen, um genetische Besonderheiten von Stamm Y11 und der Y. enterocolitica subsp. palearctica Gruppe zu identifizieren. Besonderer Fokus lag hierbei auf dem pathogenen Potential von Stamm Y11, um neue potentielle Virulenz Faktoren und Fitnessfaktoren zu identifizieren, darunter vor allem solche, die eine Rolle bei der Wirtsspezifit{\"a}t von Serobiotyp O:3/4 spielen k{\"o}nnten. Y. enterocolitica subsp. palearctica Serobiotyp O:3/4 St{\"a}mmen fehlen einige der Charakteristika der mausvirulenten Gruppe Y. enterocolitica subsp. enterocolitica, beispielsweise die Yersiniabactin kodierende‚ High-Pathogenicity Island (HPI), das Yts1 Typ 2 Sekretionssystem und das Ysa Typ 3 Sekretionssystem. Die Serobiotyp O:3/4-St{\"a}mme haben ein anderes Repertoir von Virulenz Faktoren erworben, darunter Gene bzw. genomische Inseln f{\"u}r das Ysp Typ 3 Sekretionssystem, Rtx-{\"a}hnliches putatives Toxin, Insektizid-Toxine und ein funktionelles PTS System f{\"u}r die Aufnahme von N-acetyl-galactosamin, dem aga-Operon. Nach dem Transfer des aga-Operons in Y. enterocolitica subsp. enterocolitica O:8/1B konnte Wachstum auf N-acetyl-galactosamin festgestellt werden. Neben diesen Genen k{\"o}nnen m{\"o}glicherweise auch zwei Prophagen (PhiYep-2 und PhiYep-3) und eine asn tRNA assoziierte genomische Insel (GIYep-01) zur Pathoadaptation von Y. enterocolitica subsp. palearctica Serobiotyp O:3/4 beitragen. Der PhiYep-3 Prophage und die GIYep-01 Insel weisen Rekombinationsaktivit{\"a}t auf, und PhiYep-3 wurde nicht in allen untersuchten Serobiotyp O:3/4 St{\"a}mmen gefunden. Y. enterocolitica subsp. palearctica Serobiotyp O:5,27/3 Stamm Y527P ist genetisch eng verwandt zu allen Serobiotyp O:3/4 Isolaten, wohingegen die Biotyp 1A Isolate ein mehr Mosaik-artiges Genom aufweisen und potentielle Virulenzgene sowohl mit Serobiotyp O:8/1B als auch O:3/4 gemeinsam haben, was einen gemeinsamen Vorfahren impliziert. Neben dem pYV Virulenz-Plasmid fehlen den Biotyp 1A Isolaten klassische Virulenzmarker wie das Ail Adhesin, das YstA Enterotoxin und das Virulenz-assoziierte Protein C (VapC). Interessanterweise gibt es keine betr{\"a}chtlichen Unterschiede zwischen den bekannten Virulenzfaktoren des nosokomialen Isolats und dem Umweltisolat der Biotyp 1A-Gruppe, abgesehen von einem verk{\"u}rzten Rtx Toxin-{\"a}hnlichem Genkluster und {\"U}berresten eines P2-{\"a}hnlichen Phagen im Krankenhausisolat der Serogruppe O:5.},
  subject      = {Genanalyse},
  language  = {en}
}
@article{GoebSchmittBenaventeetal.2010,
  author    = {Goeb, Eva and Schmitt, Johannes and Benavente, Ricardo and Alsheimer, Manfred},
  title     = {Mammalian Sperm Head Formation Involves Different Polarization of Two Novel LINC Complexes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68449},
  year      = {2010},
  abstract  = {Background: LINC complexes are nuclear envelope bridging protein structures formed by interaction of SUN and KASH proteins. They physically connect the nucleus with the peripheral cytoskeleton and are critically involved in a variety of dynamic processes, such as nuclear anchorage, movement and positioning and meiotic chromosome dynamics. Moreover, they are shown to be essential for maintaining nuclear shape. Findings: Based on detailed expression analysis and biochemical approaches, we show here that during mouse sperm development, a terminal cell differentiation process characterized by profound morphogenic restructuring, two novel distinctive LINC complexes are established. They consist either of spermiogenesis-specific Sun3 and Nesprin1 or Sun1g, a novel non-nuclear Sun1 isoform, and Nesprin3. We could find that these two LINC complexes specifically polarize to opposite spermatid poles likely linking to sperm-specific cytoskeletal structures. Although, as shown in co-transfection / immunoprecipitation experiments, SUN proteins appear to arbitrarily interact with various KASH partners, our study demonstrates that they actually are able to confine their binding to form distinct LINC complexes. Conclusions: Formation of the mammalian sperm head involves assembly and different polarization of two novel spermiogenesis-specific LINC complexes. Together, our findings suggest that theses LINC complexes connect the differentiating spermatid nucleus to surrounding cytoskeletal structures to enable its well-directed shaping and elongation, which in turn is a critical parameter for male fertility.},
  subject      = {Sperma},
  language  = {en}
}
@article{DummerPosseckertNestleetal.1992,
  author    = {Dummer, R. and Posseckert, G. and Nestle, F. and Witzgall, R. and Burger, M. and Becker, J. C. and Sch{\"a}fer, E. and Wiede, J. and Sebald, Walter and Burg, G.},
  title     = {Soluble interleukin-2 receptors inhibit interleukin 2-dependent proliferation and cytotoxicity: explanation for diminished natural killer cell activity in cutaneous T-cell lymphomas in vivo?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62473},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{MerzFliednerOrschescheketal.1991,
  author    = {Merz, H. and Fliedner, A. and Orscheschek, K. and Binder, T. and Sebald, Walter and M{\"u}ller-Hermelink, H. K. and Feller, A. C.},
  title     = {Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62483},
  year      = {1991},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{KruseLehrnbecherSebald1991,
  author    = {Kruse, N. and Lehrnbecher, T. and Sebald, Walter},
  title     = {Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62505},
  year      = {1991},
  abstract  = {Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.},
  subject      = {Biochemie},
  language  = {en}
}
@article{GoetzEylertEisenreichetal.2010,
  author    = {Goetz, Andreas and Eylert, Eva and Eisenreich, Wolfgang and Goebel, Werner},
  title     = {Carbon Metabolism of Enterobacterial Human Pathogens Growing in Epithelial Colorectal Adenocarcinoma (Caco-2) Cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68555},
  year      = {2010},
  abstract  = {Analysis of the genome sequences of the major human bacterial pathogens has provided a large amount of information concerning their metabolic potential. However, our knowledge of the actual metabolic pathways and metabolite fluxes occurring in these pathogens under infection conditions is still limited. In this study, we analysed the intracellular carbon metabolism of enteroinvasive Escherichia coli (EIEC HN280 and EIEC 4608-58) and Salmonella enterica Serovar Typhimurium (Stm 14028) replicating in epithelial colorectal adenocarcinoma cells (Caco-2). To this aim, we supplied [U-13C6]glucose to Caco-2 cells infected with the bacterial strains or mutants thereof impaired in the uptake of glucose, mannose and/or glucose 6-phosphate. The 13C-isotopologue patterns of protein-derived amino acids from the bacteria and the host cells were then determined by mass spectrometry. The data showed that EIEC HN280 growing in the cytosol of the host cells, as well as Stm 14028 replicating in the Salmonella-containing vacuole (SCV) utilised glucose, but not glucose 6-phosphate, other phosphorylated carbohydrates, gluconate or fatty acids as major carbon substrates. EIEC 4608-58 used C3-compound(s) in addition to glucose as carbon source. The labelling patterns reflected strain-dependent carbon flux via glycolysis and/or the Entner-Doudoroff pathway, the pentose phosphate pathway, the TCA cycle and anapleurotic reactions between PEP and oxaloacetate. Mutants of all three strains impaired in the uptake of glucose switched to C3-substrate(s) accompanied by an increased uptake of amino acids (and possibly also other anabolic monomers) from the host cell. Surprisingly, the metabolism of the host cells, as judged by the efficiency of 13C-incorporation into host cell amino acids, was not significantly affected by the infection with either of these intracellular pathogens.},
  subject      = {Metabolismus},
  language  = {en}
}
@article{DrescherBluethgenSchmittetal.2010,
  author    = {Drescher, Jochen and Bluethgen, Nico and Schmitt, Thomas and Buehler, Jana and Feldhaar, Heike},
  title     = {Societies Drifting Apart? Behavioural, Genetic and Chemical Differentiation between Supercolonies in the Yellow Crazy Ant Anoplolepis gracilipes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68573},
  year      = {2010},
  abstract  = {Background: In populations of most social insects, gene flow is maintained through mating between reproductive individuals from different colonies in periodic nuptial flights followed by dispersal of the fertilized foundresses. Some ant species, however, form large polygynous supercolonies, in which mating takes place within the maternal nest (intranidal mating) and fertilized queens disperse within or along the boundary of the supercolony, leading to supercolony growth (colony budding). As a consequence, gene flow is largely confined within supercolonies. Over time, such supercolonies may diverge genetically and, thus, also in recognition cues (cuticular hydrocarbons, CHC's) by a combination of genetic drift and accumulation of colony-specific, neutral mutations. Methodology/Principal Findings: We tested this hypothesis for six supercolonies of the invasive ant Anoplolepis gracilipes in north-east Borneo. Within supercolonies, workers from different nests tolerated each other, were closely related and showed highly similar CHC profiles. Between supercolonies, aggression ranged from tolerance to mortal encounters and was negatively correlated with relatedness and CHC profile similarity. Supercolonies were genetically and chemically distinct, with mutually aggressive supercolony pairs sharing only 33.1\%617.5\% (mean 6 SD) of their alleles across six microsatellite loci and 73.8\%611.6\% of the compounds in their CHC profile. Moreover, the proportion of alleles that differed between supercolony pairs was positively correlated to the proportion of qualitatively different CHC compounds. These qualitatively differing CHC compounds were found across various substance classes including alkanes, alkenes and mono-, di- and trimethyl-branched alkanes. Conclusions: We conclude that positive feedback between genetic, chemical and behavioural traits may further enhance supercolony differentiation through genetic drift and neutral evolution, and may drive colonies towards different evolutionary pathways, possibly including speciation.},
  subject      = {Ameisen},
  language  = {en}
}
@article{SieversBilligGottschalketal.2010,
  author    = {Sievers, Claudia and Billig, Gwendolyn and Gottschalk, Kathleen and Rudel, Thomas},
  title     = {Prohibitins Are Required for Cancer Cell Proliferation and Adhesion},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68548},
  year      = {2010},
  abstract  = {Prohibitin 1 (PHB1) is a highly conserved protein that together with its homologue prohibitin 2 (PHB2) mainly localizes to the inner mitochondrial membrane. Although it was originally identified by its ability to inhibit G1/S progression in human fibroblasts, its role as tumor suppressor is debated. To determine the function of prohibitins in maintaining cell homeostasis, we generated cancer cell lines expressing prohibitin-directed shRNAs. We show that prohibitin proteins are necessary for the proliferation of cancer cells. Down-regulation of prohibitin expression drastically reduced the rate of cell division. Furthermore, mitochondrial morphology was not affected, but loss of prohibitins did lead to the degradation of the fusion protein OPA1 and, in certain cancer cell lines, to a reduced capability to exhibit anchorage-independent growth. These cancer cells also exhibited reduced adhesion to the extracellular matrix. Taken together, these observations suggest prohibitins play a crucial role in adhesion processes in the cell and thereby sustaining cancer cell propagation and survival.},
  subject      = {Krebs <Medizin>},
  language  = {en}
}
@article{MuellerSebaldOschkinat1994,
  author    = {M{\"u}ller, T. and Sebald, Walter and Oschkinat, H.},
  title     = {Antagonist design through forced electrostatic mismatch},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62408},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{ReuschArnoldHeusseretal.1994,
  author    = {Reusch, P. and Arnold, S. and Heusser, C. and Wagner, K. and Weston, B. and Sebald, Walter},
  title     = {Neutralizing monoclonal antibodies define two different functional sites in human interleukin-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62418},
  year      = {1994},
  abstract  = {Human interleukin-4 (IL-4) is a small four-helix-bundle protein which is essential for organizing defense reactions against macroparasites, in particular helminths. Human IL-4 also appears to exert a pathophysiological role during various IgE-mediated allergic diseases. Seven different monoclonal antibodies neutralizing the activity of human IL-4 were studied in order to identify functionally important epitopes. A collection of 41 purified IL-4 variants was used to analyse how defined amino acid replacements affect binding affinity for each individual mAb. Specific amino acid positions could be assigned to four different epitopes. mAbs recognizing epitopes on helix A and/or C interfered with IL-4 receptor binding and thus inhibited IL-4 function. However, other mAbs also inhibiting IL-4 function recognized an epitope on helix D of IL-4 and did not inhibit IL-4 binding to the receptor protein. One mAb, recognizing N-terminal and C-terminal residues, partially competed for binding to the receptor. The results of these mAb epitope analyses confirm and extend previous data on the functional consequences of the amino acid replacements which showed that amino acid residues in helices A and C of IL-4 provide a binding site for the cloned IL-4 receptor and that a signalling site in helix D interacts with a further receptor protein.},
  subject      = {Biochemie},
  language  = {en}
}
@article{DemchukMuellerOschkinatetal.1994,
  author    = {Demchuk, E. and Mueller, T. and Oschkinat, H. and Sebald, Walter and Wade, R. C.},
  title     = {Receptor binding properties of four-helix-bundle growth factors deduced from electrostatic analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62424},
  year      = {1994},
  abstract  = {Hormones of the hematopoietin class mediate signal transduction by binding to specific transmembrane receptors. Structural data show that the human growth hormone (hGH) forms a complex with a homodimeric receptor and that hGH is a member of a class of hematopoietins possessing an antiparallel 4-a-helix bundle fold. Mutagenesis experiments suggest that electrostatic interactions may have an important influence on hormonereceptor recognition. In order to examine the specificity of hormone-receptor complexation, an analysis was made of the electrostatic potentials of hGH, interleukin-2 (IL-2), interleukin-4 (IL-4), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and the hGH and IL-4 receptors. The binding surfaces of hGH and its receptor, and of IL-4 and its receptor, show complementary electrostatic potentials. The potentials of the hGH and its receptor display approximately 2-fold rotational symmetry because the receptor subunits are identical. In contrast, the potentials of GM-CSF and IL-2 Iack such symmetry, consistent with their known high affinity for hetero-oligomeric receptors. Analysis of the electrostatic potentials supports a recently proposed hetero-oligomeric model for a high-affinity IL-4 receptor and suggests a possible new receptor binding mode for G-CSF; it also provides valuable information for guiding structural and mutagenesis studies of signal-transducing proteins and their receptors.},
  subject      = {Biochemie},
  language  = {en}
}
@article{LehrnbecherPootOrschescheketal.1994,
  author    = {Lehrnbecher, T. and Poot, M. and Orscheschek, K. and Sebald, Walter and Feller, A. C. and Merz, H.},
  title     = {Interleukin 7 as interleukin 9 drives phytohemagglutinin-activated T cells through several cell cycles; no synergism between interleukin 7, interleukin 9 and interleukin 4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62438},
  year      = {1994},
  abstract  = {The effects of the interlenkins IL-7 and IL-9 on cell cycle progression were investigated by conventional [3H]thymidine incorporation and by the bivariate BrdU/Hoechst technique. 8oth IL· 7 and IL-9 drive phytohemagglutinin-activated T cells through more than one cell cycle, but IL-7 wasmorepotent on cell cycle progression than IL-9. Neither synergistic nor inhibitory effects were seen between various combinations of the lymphokines IL-7, IL-9 and IL-4 compared to each lymphokine alone. When T cells are activated with phytohemagglutinin for 3 days, all or most IL-4 responsive cells respond to IL-7 as weil, whereas only a part of IL-7 responders are IL-4 responders. In contrast, when T cells are activated with phytohemagglutinin for 7 days, the quantitative data of the cell cycle distribution soggest that the population of IL-7 responders is at least an overlapping, if not a real subset of the population of the IL-4 responders.},
  subject      = {Biochemie},
  language  = {en}
}
@article{PreiserSchmartzVanderLindenetal.1991,
  author    = {Preiser, J. C. and Schmartz, D. and Van der Linden, P. and Content, J. and Vanden Bussche, P. and Buurman, W. and Sebald, Werner and Dupont, E. and Pinsky, M. R. and Vincent, J. L.},
  title     = {Interleukin-6 administration has no acute hemodynamic or hematologic effect in the dog},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62511},
  year      = {1991},
  abstract  = {To investigate the possible hemodynamic efl'ects of interleukin-6 (IL-6), a single dose of 15 mcg/kg of recombinant IL-6 isolated from Escherichia coli was injected intravenously in six pentobarbital-anesthetized dogs. After 30 min, saline infusion was performed to maintain the - pulmonary artery balloon-occluded pressure at baseline Ievel. The animals were observed for up to 5 hours. No other hemodynamic alteration was observed than a gradual decline in cardiac output attributed to anesthesia. Hematologic variables, blood glucose, and total serum proteins were also constant. IL-6 levels were markedly elevated in the blood, bot no tumor necrosis factor activity was detected. Thus a primary role for IL-6 in the early cardiovascular alterations associated with septic shock seems unlikely.},
  subject      = {Biochemie},
  language  = {en}
}
@article{TonyLehrnbecherMerzetal.1991,
  author    = {Tony, H. P. and Lehrnbecher, T. and Merz, H. and Sebald, Werner and Wilhelm, M.},
  title     = {Regulation of IL-4 responsiveness in lymphoma B cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62520},
  year      = {1991},
  abstract  = {The responsiveness to IL-4 with and without costimulation with anti-IgM antibodies or phorbolester was studied in 35 cases of low grade non-Hodgkin Iymphoma by analyzing enhancement of CD23 and HLA dass li expression. The predominant phenotype responds directly to IL-4. Separate differentiation states can be distinguished according to coordinate or differential upregulation of CD23 and HLA dass II molecules by IL-4 alone, and differences in responsiveness to anti-IgM antibodies. A particular subgroup of B-lymphoma cells defines a separate stage of B-eeil differentiation. They fail to express high affinity binding sites for IL-4 and accordingly do not respond to IL-4- mediated signals. Cross-linking membrane lgM receptors or direct activation of protein kinase C via phorbolester induces IL-4 receptor expression and subsequent IL-4 reactivity.},
  subject      = {Biochemie},
  language  = {en}
}
@phdthesis{Beisser2011,
  author    = {Beisser, Daniela},
  title     = {Integrated functional analysis of biological networks},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70150},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {In recent years high-throughput experiments provided a vast amount of data from all areas of molecular biology, including genomics, transcriptomics, proteomics and metabolomics. Its analysis using bioinformatics methods has developed accordingly, towards a systematic approach to understand how genes and their resulting proteins give rise to biological form and function. They interact with each other and with other molecules in highly complex structures, which are explored in network biology. The in-depth knowledge of genes and proteins obtained from high-throughput experiments can be complemented by the architecture of molecular networks to gain a deeper understanding of biological processes. This thesis provides methods and statistical analyses for the integration of molecular data into biological networks and the identification of functional modules, as well as its application to distinct biological data. The integrated network approach is implemented as a software package, termed BioNet, for the statistical language R. The package includes the statistics for the integration of transcriptomic and functional data with biological networks, the scoring of nodes and edges of these networks as well as methods for subnetwork search and visualisation. The exact algorithm is extensively tested in a simulation study and outperforms existing heuristic methods for the calculation of this NP-hard problem in accuracy and robustness. The variability of the resulting solutions is assessed on perturbed data, mimicking random or biased factors that obscure the biological signal, generated for the integrated data and the network. An optimal, robust module can be calculated using a consensus approach, based on a resampling method. It summarizes optimally an ensemble of solutions in a robust consensus module with the estimated variability indicated by confidence values for the nodes and edges. The approach is subsequently applied to two gene expression data sets. The first application analyses gene expression data for acute lymphoblastic leukaemia (ALL) and differences between the subgroups with and without an oncogenic BCR/ABL gene fusion. In a second application gene expression and survival data from diffuse large B-cell lymphomas are examined. The identified modules include and extend already existing gene lists and signatures by further significant genes and their interactions. The most important novelty is that these genes are determined and visualised in the context of their interactions as a functional module and not as a list of independent and unrelated transcripts. In a third application the integrative network approach is used to trace changes in tardigrade metabolism to identify pathways responsible for their extreme resistance to environmental changes and endurance in an inactive tun state. For the first time a metabolic network approach is proposed to detect shifts in metabolic pathways, integrating transcriptome and metabolite data. Concluding, the presented integrated network approach is an adequate technique to unite high-throughput experimental data for single molecules and their intermolecular dependencies. It is flexible to apply on diverse data, ranging from gene expression changes over metabolite abundances to protein modifications in a combination with a suitable molecular network. The exact algorithm is accurate and robust in comparison to heuristic approaches and delivers an optimal, robust solution in form of a consensus module with confidence values. By the integration of diverse sources of information and a simultaneous inspection of a molecular event from different points of view, new and exhaustive insights into biological processes can be acquired.},
  subject      = {Bioinformatik},
  language  = {en}
}
@article{KueblerReutherKirchneretal.1994,
  author    = {K{\"u}bler, N. and Reuther, J. and Kirchner, T. and Pfaff, M. and M{\"u}ller-Hermelink, H. K. and Albert, R. and Sebald, Walter},
  title     = {IgG monoclonal antibodies that inhibit osteoinductivity of human bone matrix-derived proteins (hBMP/NCP)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62388},
  year      = {1994},
  abstract  = {Monoclonal hBMP/NCP (human bone morphogenetic protein anrl associaterl noncollagenous proteins) antiborlies of the lgG class were prorlucerl. In vitro, 12 of 19 hBMP/NCP antiborlies showerl functional inhibition of hBMP/ NCP-induced chondroneogenesis in a neonatal muscle tissue assay. Inducing factors were characterized by their inhibiting antibodies with immunoblotting. Several peptide factors seem to be involved in the cascade of inducerl chondro- and osteogenesis.},
  subject      = {Biochemie},
  language  = {en}
}
@article{TonyShenReuschetal.1994,
  author    = {Tony, H. P. and Shen, B. J. and Reusch, P. and Sebald, Walter},
  title     = {Design of human interleukin-4 antagonists inhibiting interleukin-4-dependent and interleukin-13-dependent responses in T-cells and B-cells with high efficiency},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62394},
  year      = {1994},
  abstract  = {Human interleukin-4 possesses two distinct sites for receptor activation. A signaHing site, comprising residues near the C-terminus on helix D, determines the efficacy of interleukin-4 signal transduction without affecting the binding to the interleukin-4 receptor a subunit. A complete antagonist and a series of low-efficacy agonist variants of human interleukin-4 could be generated by introducing combinations of two or three negatively charged aspartic acid residues in this site at positions 121, 124, and 125. One of the double variants, designated [R121D,Y124D]interleukin-4, with replacements of b{\"o}th Arg121 and Tyr124 by aspartic acid residues was completely inactive in all analysed cellular responses. The loss of efficacy in [R121D,Y124D]interleukin-4 is estimated to be larger than 2000-fold. Variant [R121D,Y124D]interleukin-4 was also a perfect antagonist for inhibition of interleukin-13-dependent responses in B-cells and the TF-1 cellline with a K\(_i\) value of approximately 100 pM. In addition, inhibition of both interleukin-4-induced and interleuk.in-13- induced responses could be obtained by monoclonal antibody X2/45 raised against interleukin-4Rm the extracellular domain of the interleuk.in-4 receptor a subunit. These results indicate that efficient interleukin-4 antagonists can be designed on the basis of a sequential two-step activation model. In addition, the experiments indicate the functional participation of the interleukin-4 receptor a subunit in the interleukin-13 receptor system.},
  subject      = {Biochemie},
  language  = {en}
}
@phdthesis{Schriefer2012,
  author    = {Schriefer, Eva-Maria},
  title     = {Molekulare und biochemische Charakterisierung der β-Laktamasen von Yersinia enterocolitica und deren Sekretionsverhalten},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69580},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {In dieser Arbeit wurden zwei Aspekte der Yersinia β-Laktamasen bearbeitet: (1) Charakterisierung der β-Laktamasen hinsichtlich β-Laktam-Antibiotikaresistenz, Sekretion und Thermostabilit{\"a}t. (2) Untersuchung der Sekretionsf{\"a}higkeit von verschiedenen thermostabilen β Laktamasen {\"u}ber das Yersinia T3SS. Im ersten Teil wurden β Laktamase-Deletionsmutanten im Y. enterocolitica Serotyp O:8 Stamm WA-314 hergestellt, um den Einfluss der chromosomalen β Laktamasen auf die in vitro-Resistenz zu untersuchen. Es konnte gezeigt werden, dass WA-314 konstitutiv BlaA produziert und BlaA somit - unter nicht-induzierbaren Bedingungen - der dominante Faktor in der in vitro-Resistenz gegen{\"u}ber Penicillinen mit erweitertem Wirkungsspektrum (z.B. Ampicillin) und Cephalosporinen der 1. Generation (z.B. Cefazolin) ist. Weiterhin konnte gezeigt werden, dass die zweite chromosomale β Laktamase AmpC (BlaB) unter Zugabe von subinhibitorischen Konzentrationen von Imipenem stark induziert wird. Keine der β Laktamasen ist in der Lage, in vitro-Resistenz gegen{\"u}ber Carbapenemen und Monobactamen zu vermitteln. Die Konstruktion und Bestimmung der in vitro Antibiotika-Empfindlichkeit der β Laktamase-Deletionsmutanten dient als Grundlage f{\"u}r nachfolgende Untersuchungen im Mausinfektionsmodell. Weiterhin wurden die Transporteigenschaften beider β Laktamasen untersucht. In Gram-negativen Bakterien sind reife β Laktamasen im Periplasma lokalisiert und m{\"u}ssen somit nach der Synthese im Cytosol {\"u}ber die Cytoplasmamembran transportiert werden. Bis auf drei Ausnahmen (β Laktamasen aus Mycobacterium smegmatis, M. tuberculosis und Stenotrophomonas maltophila) sind bisher nur Sec-abh{\"a}ngige β Laktamasen beschrieben worden. Mittels Fusionsproteinen bestehend aus β Laktamase-Signalpeptiden und GFP konnte in dieser Arbeit eindeutig gezeigt werden, dass es sich bei Yersinia BlaA um ein Tat-Substrat handelt, bei Yersinia AmpC hingegen um ein Sec-Substrat. Somit konnte im Rahmen dieser Arbeit zum ersten Mal eine Tat-abh{\"a}ngige β Laktamase bei einer Bakterienart aus der Familie der Enterobacteriaceae nachgewiesen werden. Außerdem konnte gezeigt werden, dass die β Laktamase BlaA nicht diffus im Periplasma, sondern auf bestimmte Bereiche im Periplasma lokalisiert verteilt ist. Allerdings konnte die Art der Lokalisierung bisher nicht genau spezifiziert werden. Die cytosolische Faltung und die Tat-abh{\"a}ngige Translokation von BlaA lassen vermuten, dass eine besondere Thermostabilit{\"a}t von BlaA vorliegt. Deshalb wurde das BlaA-Enzym hinsichtlich seiner Thermostabilit{\"a}t und temperaturabh{\"a}ngigen enzymatischen Aktivit{\"a}t untersucht. Im Vergleich zur E. coli β Laktamase TEM-1 und der hitzestabilen TEM-1-Variante MEGA zeigte BlaA eine erh{\"o}hte Thermostabilit{\"a}t und einen starken Anstieg der Aktivit{\"a}t in einem Temperaturbereich zwischen 30 °C und 45 °C. Im zweiten Teil dieser Arbeit wurde gepr{\"u}ft, ob die charakterisierten Yersinia β Laktamasen als Reporterkonstrukte zur Untersuchung des Typ III Sekretionssystems (T3SS) geeignet sind. Y. enterocolitica besitzt ein pYV Virulenzplasmid, auf dem der vollst{\"a}ndige Satz der Gene f{\"u}r das Ysc-T3SS und die Effektor-Yops (Yersinia outer protein) lokalisiert sind. Injektion der Yops in eukaryotische Zielzellen erm{\"o}glicht das extrazellul{\"a}re {\"U}berleben der Yersinien im Wirtsorganismus. Bei YopE handelt es sich um ein gut charakterisiertes Effektor-Yop, dessen N Terminus fusioniert an den reifen Teil der β Laktamase TEM-1 bereits vielfach als Reporterkonstrukt eingesetzt wurde. Unter Verwendung des fluoreszierenden β Laktamase-Substrats CCF4-AM kann die Translokation von YopEi-TEM-1 in Zielzellen in Zellkultur-Experimenten und im Mausinfektionsmodell visualisiert werden. In dieser Arbeit sollte deshalb die T3SS-Sekretionsf{\"a}higkeit von YopE-β Laktamase-Fusionsproteinen in Abh{\"a}ngigkeit von der „Schmelztemperatur" (temperaturabh{\"a}ngige Stabilit{\"a}t, TM) untersucht werden. Yop-Substrate werden im ungefalteten Zustand (YscN wirkt dabei vermutlich als ATP-abh{\"a}ngige „Unfoldase") {\"u}ber das Ysc-„Injektisom" transloziert. YopEi-TEM-1 wird effizient sekretiert und transloziert (TM (TEM-1) = 50,8 °C). YopE-Fusionsproteine mit thermostabilen TEM-1 Varianten, YopEi-RLT bzw. YopEi-MEGA (TM (RLT) = 60,4 °C; TM (MEGA) = 69,2 °C) werden hingegen nur schwach bzw. nicht sekretiert. Weiterhin konnte gezeigt werden, dass die Sec-abh{\"a}ngige β Laktamase AmpC als YopE-Fusionsprotein (YopEi-AmpC) effizient T3SS-abh{\"a}ngig sekretiert und transloziert werden kann; das native Tat-Substrat BlaA (YopEi-BlaA) kann jedoch weder sekretiert noch transloziert wird. Eine m{\"o}gliche Erkl{\"a}rung w{\"a}re, dass die ATPase YscN nicht in der Lage ist, BlaA und die thermostabilen TEM-1-Varianten zu entfalten und {\"u}ber das T3SS zu sekretieren und zu translozieren. RLT und MEGA k{\"o}nnen hingegen mithilfe ihrer nativen Signalsequenz {\"u}ber das Sec-System (und somit im ungefalteten Zustand) transloziert werden.},
  subject      = {Yersinia enterocolitica},
  language  = {de}
}
@misc{Wenzel2011,
  type      = {Master Thesis},
  author    = {Wenzel, Frank},
  title     = {Smell and repel: Resin based defense mechanisms and interactions between Australian ants and stingless bees},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65960},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Bees are subject to permanent threat from predators such as ants. Their nests with large quantities of brood, pollen and honey represent lucrative targets for attacks whereas foragers have to face rivalry at food sources. This thesis focused on the role of stingless bees as third party interactor on ant-aphid-associations as well as on the predatory potential represented by ants and defense mechanisms against this threat. Regular observations of an aphid infested Podocarpus for approaching stingless bees yielded no results. Another aim of this thesis was the observation of foraging habits of four native and one introduced ant species for assessment of their predatory potential to stingless bees. All species turned out to be dietary balanced generalists with one mostly carnivorous species and four species predominantly collecting nectar roughly according to optimal foraging theory. Two of the species monitored, Rhytidoponera metallica and Iridomyrmex rufoniger were considered potential nest robbers. As the name implies, stingless bees lack the powerful weapon of their distant relatives; hence they specialized on other defense strategies. Resin is an important, multipurpose resource for stingless bees that is used as material for nest construction, antibiotic and for defensive means. For the latter purpose highly viscous resin is either directly used to stick down aggressors or its terpenic compounds are included in the bees cuticular surface. In a feeding choice experiment, three ant species were confronted with the choice between two native bee species - Tetragonula carbonaria and Austroplebeia australis - with different cuticular profiles and resin collection habits. Two of the ant species, especially the introduced Tetramorium bicarinatum did not show any preferences. The carnivorous R. metallica predominantly took the less resinous A. australis as prey. The reluctance towards T. carbonaria disappeared when the resinous compounds on its cuticle had been washed off with hexane. To test whether the repulsive reactions were related to the stickiness of the resinous surface or to chemical substances, hexane extracts of bees' cuticles, propolis and three natural tree resins were prepared. In the following assay responses of ants towards extract treated surfaces were observed. Except for one of the resin extracts, all tested substances had repellent effects to the ants. Efficacy varied with the type of extract and species. Especially to the introduced T. bicarinatum the cuticular extract had no effect. GCMS-analyses showed that some of the resinous compounds were also found in the cuticular profile of T. carbonaria which featured reasonable analogies to the resin of Corymbia torelliana that is highly attractive for stingless bees. The results showed that repellent effects were only partially related to the sticky quality of resin but were rather caused by chemical substances, presumably sesqui- and diterpenes. Despite its efficacy this defense strategy only provides short time repellent effects sufficient for escape and warning of nest mates to initiate further preventive measures.},
  subject      = {Stachellose Biene},
  language  = {en}
}
@phdthesis{Heddergott2011,
  author    = {Heddergott, Niko},
  title     = {Zellbiologische Aspekte der Motilit{\"a}t von Trypanosoma brucei unter Ber{\"u}cksichtigung der Interaktion mit der Mikroumwelt},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-56791},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Trypanosomen sind Protozoen, die Krankheiten bei Mensch und Tier verursachen, die unbehandelt infaust verlaufen. Die Zellen sind hoch motil, angetrieben von einem einzelst{\"a}ndigen Flagellum, welches entlang des Zellk{\"o}rpers angeheftet ist. Selbst in Zellkultur h{\"o}ren Trypanosomen niemals auf sich zu bewegen und eine Ablation funktioneller Bestandteile des Flagellarapparates ist letal f{\"u}r Blutstromformen. Es wurde gezeigt, dass Motilit{\"a}t notwendig ist f{\"u}r die Zellteilung, Organellenpositionierung und Infektiosit{\"a}t. Dies macht Trypanosomen zu besonders geeigneten Modellorganismen f{\"u}r die Untersuchung der Motilit{\"a}t. Dennoch ist erstaunlich wenig {\"u}ber die Motilit{\"a}t bei Trypanosomen bekannt. Dies gilt auch noch genereller f{\"u}r die Protozoen. Unl{\"a}ngst ist dieses Gebiet allerdings in den Fokus vieler Arbeiten ger{\"u}ckt, was bereits erstaunliche, neue Erkenntnisse hervorgebracht hat. Doch Vieles ist noch nicht abschliessend gekl{\"a}rt, so z.B. wie der Flagellarschlag genau reguliert wird, oder wie sich der Schlag des Flagellums entlang des Zellk{\"o}rpers ausbreitet. Die vorliegende Arbeit befasst sich besonders mit den Einfl{\"u}ssen, die die Mikroumgebung auf die Motilit{\"a}t von Blutstromform-Trypanosomen aus{\"u}bt. In ihrem nat{\"u}rlichen Lebensraum finden sich Trypanosomen in einer hoch komplexen Umgebung wieder. Dies gilt sowohl f{\"u}r den Blutkreislauf, als auch f{\"u}r den Gewebezwischenraum in ihrem S{\"a}ugerwirt. Die hohe Konzentration von Zellen, Gewebeverb{\"a}nden und extrazellul{\"a}ren Netzwerken k{\"o}nnte man als Ansammlung von Hindernissen f{\"u}r die Fortbewegung auffassen. Diese Arbeit zeigt dagegen, dass der Mechanismus der Bewegung eine Adaptation an genau diese Umweltbedingungen darstellt, so z.B. an die Viskosit{\"a}t von Blut. Es wird auch ein Bewegungsmodell vorgestellt, das erl{\"a}utert, worin diese Adaption besteht. Dies erkl{\"a}rt auch, warum die Mehrheit der Zellen einer Trypanosomenkultur eine ungerichtete Taumel-Bewegung aufweist in nieder-viskosem Medium, das keine solchen "Hindernisse" enth{\"a}lt. Die Zugabe von Methylcellulose in einer Konzentration von ca. 0,5\% (w/v) erwies sich als geeigneter Ersatz von Blut, um optimale Bedingungen f{\"u}r gerichtetes Schwimmen von Blutstromform Trypanosomen zu erreichen. Zus{\"a}tzlich wurden in dieser Arbeit unterschiedliche Arten von Hindernissen, wie Mikroperlen (Beads) oder molekulare Netzwerke, sowie artifizielle, geordnete Mikrostrukturen verwendet, um die Interaktion mit einer festen Matrix zu untersuchen. In deren Anwesenheit war sowohl die Schwimmgeschwindigkeit, als auch der Anteil an persistent schwimmenden Trypanosomen erh{\"o}ht. Zellen, die frei schwimmend in Fl{\"u}ssigkeiten vorkommen (wie Euglena oder Chlamydomonas), werden effizient durch einen planaren Schlag des Flagellums angetrieben. Trypanosomen hingegen mussten sich evolution{\"a}r an eine komplexe Umgebung anpassen, die mit einer zu raumgreifenden Welle interferieren w{\"u}rde. Der dreidimensionale Flagellarschlag des, an die Zelloberfl{\"a}che angehefteten, Flagellums erlaubt den Trypanosomen eine effiziente Fortbewegung durch die Interaktion mit Objekten in jedweder Richtung gleichermassen. Trypanosomen erreichen dies durch eine hydrodynamisch verursachte Rotation ihres Zellk{\"o}rpers entlang ihrer L{\"a}ngsachse, entgegen dem Uhrzeigersinn. Der Einfluss der Mikroumgebung wurde in fr{\"u}heren Untersuchungen bisher vernachl{\"a}ssigt, ist zum Verst{\"a}ndnis der Motilit{\"a}t von T. brucei jedoch unerl{\"a}sslich. Ein weiterer, bisher nicht untersuchter Aspekt der Beeinflussung der Motilit{\"a}t durch die Umwelt sind hydrodynamische Str{\"o}mungseffekte, denen Trypanosomen im kardiovaskul{\"a}ren System ausgesetzt sind. Diese wurden in dieser Arbeit mittels Mikrofluidik untersucht. Um unser Verst{\"a}ndnis der Motilit{\"a}t von Trypanosomen von 2D, wie {\"u}blich in der Motilit{\"a}tsanalyse mittels Lebend-Zell-Mikroskopie, auf drei Dimensionen auszudehnen, wurde als bildgebendes Verfahren auch die Holographie eingesetzt. Mikrofluidik und Holographie sind beides aufkommende Techniken mit großem Anwendungspotential in der Biologie, die zuvor noch nie f{\"u}r die Motilit{\"a}tsanalyse von Trypanosomen eingesetzt worden waren. Dies erforderte daher interdisziplin{\"a}re Kooperationen. Zus{\"a}tzlich wurde in dieser Arbeit auch ein vollst{\"a}ndig automatisiertes und Software-gesteuertes Fluoreszenzmikroskopiesystem entwickelt, das in der Lage ist, einzelne Zellen durch entsprechende Steuerung des Mikroskoptisches autonom zu verfolgen und somit eine Bewegungsanalyse in Echtzeit erm{\"o}glicht, ohne weitere Benutzerinteraktion. Letztendlich konnte dadurch auch die Bewegung der schlagenden Flagelle und des gesamten Zellk{\"o}rpers mit hoher zeitlicher und r{\"a}umlicher Aufl{\"o}sung mittels Hochgeschwindigkeits-Fluoreszenzmikroskopie aufgekl{\"a}rt werden.},
  subject      = {Trypanosoma brucei},
  language  = {de}
}
@phdthesis{Schmull2011,
  author    = {Schmull, Sebastian},
  title     = {Charakterisierung der pathogenetisch-relevanten Rolle von SF1 beim Nebennierenrindenkarzinom},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66398},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Tumore der Nebennieren stellen h{\"a}ufige Tumore dar, welche bei mindestens 3 \% der Population {\"u}ber 50-J{\"a}hriger vorkommen. Im Gegensatz dazu ist das Nebennierenrindenkarzinom mit einer Inzidenz von 1-2 Einwohner pro Million ein sehr seltener Tumor. Da seine Prognose allerdings ung{\"u}nstig, und diese maßgeblich davon abh{\"a}ngt wie fortgeschritten der Tumor bei Diagnosestellung ist, ist es wichtig, dass die richtige Diagnose fr{\"u}hzeitig gestellt wird. Bis heute ist kein zuverl{\"a}ssiger immunhistochemischer Nebennierenrindenkarzinom-spezifischer Marker etabliert um das Nebennierenrindenkarzinom von anderen retroperitonealen Tumoren zu differenzieren. Sasano et al. schlug bereits 1995 erstmalig den Transkriptionsfaktor Steroidogenic Factor 1 (SF1) als Marker zur Differenzierung von Nebennierenrinden- und Nicht-Nebennierenrindentumoren vor. Allerdings wurde die diagnostische Wertigkeit bisher nur in sehr kleinen Fallserien mit insgesamt nur 17 Nebennierenrindenkarzinomen untersucht. In der vorliegenden Arbeit wurde die SF1 Protein-Expression bei 163 Nebennierenrindenkarzinomen, 52 Nebennierenrinden-Adenomen, 12 normalen steroidogenen Geweben (6 Nebennieren und 6 Ovare), sowie 73 Nicht-Steroidtumoren immunhistochemisch untersucht. Hierbei zeigte sich, das SF1 bei 158 von 161 evaluierbaren Nebennierenrindenkarzinomen und bei allen Proben von normalen und gutartigen Geweben (n=64) nachweisbar war. Im Gegensatz dazu war keine der 73 Nicht-Steroidgeweben SF1 positiv, so dass die diagnostische Genauigkeit extrem gut ist (Sensitivit{\"a}t: 98.6 \%, Spezifit{\"a}t: 100 \%, positive und negative predictive value jeweils 100 \% und 97.3 \%). In einem zweiten Schritt wurde untersucht ob die Protein-Expression von SF1 beim Nebennierenrindenkarzinom auch prognostische Bedeutung hat. Hierbei zeigte sich, dass Patienten mit Tumoren mit starker SF1 F{\"a}rbung (30 \%) ein deutlich schlechteres tumorstadium-adjustiertes Rezidiffreies- und Gesamt-{\"U}berleben haben als Patienten mit geringer SF1 Expression (hazard ratio: 2.45). Zus{\"a}tzlich zu den immunhistochemischen Untersuchungen wurden FISH Analysen durchgef{\"u}hrt. Hierbei zeigte sich allerdings keine signifikante Korrelation zwischen SF1 Gendosis und der SF1 Protein-Expression, so dass zu vermuten ist, dass SF1 maßgeblich auf Transkriptions- und Translationsebene reguliert wird. In einem Versuch diese Frage zu beantworten wurden zwei mutmaßliche SF1 Interaktionspartner, FATE1 und DAX1, genauer immunhistochemisch untersucht. Hierbei wurde deutlich, dass FATE1 bei 62 von 141 evaluierbaren Nebenierenrindenkarzinomen und 12 von 62 normalen und gutartigen Geweben nachweisbar war. Im Gegensatz hierzu waren alle 9 Nicht-Steroidgewebe FATE1 negativ. Dies zeigt, das FATE1 nicht zur Diagnostik nutzbar ist (Sensitivit{\"a}t: 61 \%, Spezifit{\"a}t: 100 \%, positive und negative predictive value 100 \% bzw. 14 \%). Die DAX1 Analyse zeigte, dass alle 20 normalen und gutartigen Gewebe eine positive DAX1 F{\"a}rbereaktion zeigten. Von 126 Nebennierenrindenkarzinomen waren 71 DAX1 positiv. Von den 8 untersuchten Nicht-Steroidgeweben waren 6 DAX1 positiv. Diese Ergebnisse belegen, dass auch DAX1 keine diagnostische Genauigkeit besitzt (Sensitivit{\"a}t: 56 \%, Spezifit{\"a}t: 25 \%, positive und negative predictive value 92 \% bzw. 4 \%). Die Untersuchung der prognostischen F{\"a}higkeiten von FATE1 und DAX1 zeigte, dass Patienten mit Tumoren mit starker FATE1 F{\"a}rbung (39 \%) ein schlechteres tumorstadium-adjustiertes Gesamt- aber nicht Rezidiffreies-{\"U}berleben haben als Patienten mit niedriger FATE1 Protein-Expression (hazard ratio: 2.01). Weiterhin wurde deutlich, dass DAX1 keine deutlichen prognostischen F{\"a}higkeiten besitzt. Zusammenfassend l{\"a}ßt sich aus der vorliegenden Arbeit folgern, das SF1 aktuell der beste diagnostische Marker zur Diagnose von Tumoren der Nebennierenrinde ist und damit Eingang in die histopathologische Routine-Diagnostik von Nebennierentumoren finden wird. Zus{\"a}tzlich ist die SF1 Expression ein sehr guter prognostischer Marker beim Nebennierenrindenkarzinom, wobei sich die prognostische Aussage durch zus{\"a}tzliche F{\"a}rbung von FATE1 und DAX1 nur unwesentlich verbessern l{\"a}ßt.},
  subject      = {Nebennierenrindenkrebs},
  language  = {de}
}
@phdthesis{Azzami2011,
  author    = {Azzami, Klara},
  title     = {Antibakterielle und antivirale Abwehrreaktionen in unterschiedlichen Entwicklungsstadien der Honigbiene (Apis mellifera)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66452},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Das angeborene Immunsystem von Insekten besteht aus einer humoralen Komponente, einer zellul{\"a}ren Komponente und dem Prophenoloxidase-aktivierenden System. Fast alle Erkenntnisse {\"u}ber das angeborene Immunsystem stammen von Arbeiten mit Modellorganismen wie z.B. Drosophila oder Anopheles gambiae. Wie genau das Immunsystem der Honigbiene (Apis mellifera) funktioniert, ist jedoch noch relativ unbekannt. In der vorliegenden Arbeit wurden die unterschiedlichen Immunreaktionen aller drei Entwicklungsstadien der Honigbiene nach artifizieller Infektion mit Gram-negativen und Gram-positiven Bakterien (Escherichia coli und Micrococcus flavus) und dem Akuten Bienen Paralyse Virus (ABPV) untersucht und verglichen. Eine E. coli-Injektion zeigt bei Larven und adulten Arbeiterinnen nur wenig Auswirkung auf das {\"a}ußere Erscheinungsbild und die {\"U}berlebensrate. In beiden Entwicklungsstadien wird die humorale Immunantwort stark induziert, erkennbar an der Expression der antimikrobiellen Peptide (AMPs) Hymenoptaecin, Defensin1 und Abaecin. Zus{\"a}tzlich werden allein in Jungbienen nach bakterieller Infektion vier weitere immunspezifische Proteine exprimiert. Unter anderem eine Carboxylesterase (CE1) und das Immune-Responsive Protein 30 (IRp30). Die Expression von CE1 und IRp30 zeigt dabei den gleichen zeitlichen Verlauf wie die der AMPs. In Jungbienen kommt es zudem nach E. coli-Injektion zu einer raschen Abnahme an lebenden Bakterien in der H{\"a}molymphe, was auf eine Aktivierung der zellul{\"a}ren Immunantwort schließen l{\"a}sst. {\"A}ltere Bienen und Winterbienen zeigen eine st{\"a}rkere Immunkompetenz als Jungbienen. Selbst nicht-infizierte Winterbienen exprimieren geringe Mengen der immunspezifischen Proteine IRp30 und CE1. Die Expression von IRp30 kann dabei durch Verwundung oder Injektion von E. coli noch gesteigert werden. Eine weitere Besonderheit ist die im Vergleich zu Jungbienen raschere Abnahme an lebenden Bakterien in der H{\"a}molymphe bis hin zur vollst{\"a}ndigen Eliminierung. Die Reaktion von Puppen auf eine bakterielle Infektion war v{\"o}llig unerwartet. Nach Injektion von E. coli-Zellen kommt es innerhalb von 24 h p.i. zu einem t{\"o}dlichen Kollaps, der sich in einer Grauf{\"a}rbung des gesamten Puppenk{\"o}rpers {\"a}ußert. Da keine Expression von AMPs nachzuweisen war, wird die humorale Immunantwort offensichtlich nicht induziert. Auch die zellul{\"a}re Immunantwort scheint nicht aktiviert zu werden, denn es konnte keine Abnahme an lebenden E. coli-Zellen beobachtet werden. Aufgrund dieser fehlenden Immunreaktionen vermehrt sich E. coli im H{\"a}mocoel infizierter Puppen und scheint damit deren Tod herbeizuf{\"u}hren. Nach viraler Infektion wurden in allen drei Entwicklungsstadien der Honigbiene g{\"a}nzlich andere Reaktionen beobachtet als nach bakterieller Infektion. Bei dem verwendeten Akuten Bienen Paralyse Virus (ABPV) handelt es sich um ein Picorna-{\"a}hnliches Virus, dessen Vermehrung in der H{\"a}molymphe {\"u}ber die massive Synthese der Capsidproteine verfolgt werden kann. Eine Injektion von sehr wenigen ABPV-Partikeln ins H{\"a}mocoel hat dramatische Auswirkungen auf Larven. Nach Virusinjektion kommt es innerhalb weniger Stunden zu einer raschen Virusvermehrung und schon 24 h p.i. zum Tod, h{\"a}ufig begleitet von einer Schwarzf{\"a}rbung der gesamten Larve. Kurz vor dem Ableben kommt es neben dem Abbau hochmolekularer Speicherproteine zur Expression zahlreicher Proteine, die u.a. an der Translation oder dem Schutz vor oxidativem Stress beteiligt sind. Auf Jungbienen hat eine ABPV-Infektion keine so dramatischen Auswirkungen wie auf Larven. Sie zeigen lediglich Zeichen von Paralyse, zudem {\"u}berleben sie l{\"a}nger bei h{\"o}heren injizierten Partikelzahlen, die Virusvermehrung ist langsamer und es kommt zu keiner starken Ver{\"a}nderung des H{\"a}molymph-Proteinmusters. Es konnte gezeigt werden, dass es in ABPV-infizierten Larven oder adulten Bienen zu keiner erkennbaren Aktivierung des humoralen Immunsystems in Form von exprimierten AMPs kommt. Zudem scheint die humorale Immunantwort auch nicht unterdr{\"u}ckt zu werden, denn nach gleichzeitiger Injektion von E. coli und ABPV kommt es neben der Expression viraler Capsidproteine auch zur Expression von AMPs. Zus{\"a}tzlich konnte in Jungbienen nach Infektion mit ABPV eine zellul{\"a}re Immunantwort in Form von Nodulation ausgeschlossen werden. {\"A}ltere Bienen scheinen nicht nur mit bakteriellen Infektionen, sondern auch mit einer ABPV-Infektion besser zurechtzukommen. Bei einer Menge an ABPV-Partikeln, die in Jungbienen sp{\"a}testens 72 h p.i. zum Tod f{\"u}hrt, ist in Winterbienen eine Virusvermehrung erst ab 96 h p.i. erkennbar und diese beeintr{\"a}chtigt die {\"U}berlebensrate kaum. Puppen sind einer Virusinfektion genauso schutzlos ausgeliefert wie einer Bakterieninfektion. Es kommt zwar zu keiner starken {\"A}nderung des {\"a}ußeren Erscheinungsbildes, jedoch bleiben Puppen in ihrer Entwicklung komplett stehen. Das Virus muss sich daher stark vermehren, allerdings nicht {\"u}berwiegend - wie bei Larven und adulten Bienen - in der H{\"a}molymphe.},
  subject      = {Biene},
  language  = {de}
}
@phdthesis{Niewalda2010,
  author    = {Niewalda, Thomas},
  title     = {Neurogenetic analyses of pain-relief learning in the fruit fly},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65035},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {All animals learn in order to cope with challenges imposed on them by their environment. This is true also for both larval and adult fruit flies as exemplified in pavlovian conditioning. The focus of this Thesis is on various aspects of the fruit flies learning ability. My main project deals with two types of learning which we call punishment-learning and pain-relief learning. Punishment learning happens when fruit flies are exposed to an odour which is followed by electric shock. After such training, flies have learned that that odour signals pain and consequently will avoid it in the future. If the sequence of the two stimuli is reversed such that odour follows shock, flies learn the odour as a signal for relief and will later on approach it. I first report a series of experiments investigating qualitative and parametric features of relief-learning; I find that (i) relief learning does result from true associative conditioning, (ii) it requires a relatively high number of training trials, (iii) context-shock training is ineffective for subsequent shock-odour learning. A further question is whether punishment-learning and pain-relief learning share genetic determinants. In terms of genetics, I test a synapsin mutant strain, which lacks all Synapsin protein, in punishment and relief-learning. Punishment learning is significantly reduced, and relief-learning is abolished. Pan-neuronal RNAi-mediated knock-down of Synapsin results in mutant-like phenotypes, confirming the attribution of the phenotype to lack of Synapsin. Also, a rescue of Synapsin in the mushroom body of syn97 mutants restores both punishment- and relief-learning fully, suggesting the sufficiency of Synapsin in the mushroom body for both these kinds of learning. I also elucidate the relationship between perception and physiology in adult fruit flies. I use odour-shock conditioning experiments to identify degrees of similarity between odours; I find that those similarity measures are consistent across generalization and discrimination tasks of diverse difficulty. Then, as collaborator of T. V{\"o}ller and A. Fiala, I investigate how such behavioural similarity/dissimilarity is reflected at the physiological level. I combine the behaviour data with calcium imaging data obtained by measuring the activity patterns of those odours in either the sensory neurons or the projection neurons at the antennal lobe. Our interpretation of the results is that the odours perceptual similarity is organized by antennal lobe interneurons. In another project I investigate the effect of gustatory stimuli on reflexive behaviour as well as their role as reinforcer in larval learning. Drosophila larvae greatly alter their behaviour in presence of sodium chloride. Increasing salt concentration modulates choice behaviour from weakly appetitive to strongly aversive. A similar concentration-behaviour function is also found for feeding: larval feeding is slightly enhanced in presence of low salt concentrations, and strongly decreased in the presence of high salt concentrations. Regarding learning, relatively weak salt concentrations function as appetitive reinforcer, whereas high salt concentrations function as aversive reinforcer. Interestingly, the behaviour-concentration curves are shifted towards higher concentrations from reflexive behaviour (choice behaviour, feeding) as compared to associative learning. This dissociation may reflect a different sensitivity in the respective sensory-motor circuitry.},
  subject      = {Taufliege},
  language  = {en}
}
@phdthesis{Saumweber2011,
  author    = {Saumweber, Timo},
  title     = {Mechanism of Learning and Plasticity in Larval Drosophila},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66354},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {According to a changing environment it is crucial for animals to make experience and learn about it. Sensing, integrating and learning to associate different kinds of modalities enables animals to expect future events and to adjust behavior in the way, expected as the most profitable. Complex processes as memory formation and storage make it necessary to investigate learning and memory on different levels. In this context Drosophila melanogaster represents a powerful model organism. As the adult brain of the fly is still quite complex, I chose the third instar larva as model - the more simple the system, the easier to isolate single, fundamental principles of learning. In this thesis I addressed several kinds of questions on different mechanism of olfactory associative and synaptic plasiticity in Drosophila larvae. I focused on short-term memory throughout my thesis. First, investigating larval learning on behavioral level, I developed a one-odor paradigm for olfactory associative conditioning. This enables to estimate the learnability of single odors, reduces the complexity of the task and simplify analyses of "learning mutants". It further allows to balance learnability of odors for generalization-type experiments to describe the olfactory "coding space". Furthermore I could show that innate attractiveness and learnability can be dissociated and found finally that paired presentation of a given odor with reward increase performance, whereas unpaired presentations of these two stimuli decrease performance, indicating that larva are able to learn about the presence as well as about the absence of a reward. Second, on behavioral level, together with Thomas Niewalda and colleagues we focussed on salt processing in the context of choice, feeding and learning. Salt is required in several physiological processes, but can neither be synthesized nor stored. Various salt concentrations shift the valence from attraction to repulsion in reflexive behaviour. Interestingly, the reinforcing effect of salt in learning is shifted by more than one order of magnitude toward higher concentrations. Thus, the input pathways for gustatory behavior appear to be more sensitive than the ones supporting gustatory reinforcement, which is may be due to the dissociation of the reflexive and the reinforcing signalling pathways of salt. Third, in cooperation with Michael Schleyer we performed a series of behavioral gustatory, olfactory preference tests and larval learning experiments. Based on the available neuroanatomical and behavioral data we propose a model regarding chemosensory processing, odor-tastant memory trace formation and the 'decision' like process. It incorporates putative sites of interaction between olfactory and gustatory pathways during the establishment as well as behavioral expression of odor-tastant memory. We claim that innate olfactory behavior is responsive in nature and suggest that associative conditioned behavior is not a simple substitution like process, but driven more likely by the expectation of its outcome. Fourth, together with Birgit Michels and colleagues we investigated the cellular site and molecular mode of Synapsin, an evolutionarily conserved, presynaptic vesicular phosphoprotein and its action in larval learning. We confirmed a previously described learning impairment upon loss of Synapsin. We localized this Synapsin dependent memory trace in the mushroom bodies, a third-order "cortical" brain region, and could further show on molecular level, that Synapsin is as a downstream element of the AC-cAMP-PKA signalling cascade. This study provides a comprehensive chain of explanation from the molecular level to an associative behavioral change. Fifth, in the main part of my thesis I focused on molecular level on another synaptic protein, the Synapse associated protein of 47kDa (Sap47) and its role in larval behavior. As a member of a phylogenetically conserved gene family of hitherto unknown function. It is localized throughout the whole neuropil of larval brains and associated with presynaptic vesicles. Upon loss of Sap47 larvae exhibit normal sensory detection of the to-be-associated stimuli as well as normal motor performance and basic synaptic transmission. Interestingly, short-term plasticity is distorted and odorant-tastant associative learning ability is reduced. This defect in associative function could be rescued by restoring Sap47 expression. Therefore, this report is the first to suggest a function for Sap47 and specifically argues that Sap47 is required for synaptic as well as for behavioral plasticity in Drosophila larva. This prompts the question whether its homologs are required for synaptic and behavioral plasticity also in other species. Further in the last part of my thesis I contributed to the study of Ayse Yarali. Her central topic was the role of the White protein in punishment and relief learning in adult flies. Whereas stimuli that precede shock during training are subsequently avoided as predictors for punishment, stimuli that follow shock during training are later on approached, as they predict relief. Concerning the loss of White we report that pain-relief learning as well as punishment learning is changed. My contribution was a comparison between wild type and the white1118 mutant larvae in odor-reward learning. It turned out that a loss of White has no effect on larval odorant-tastant learning. This study, regarding painrelief learning provides the very first hints concerning the genetic determinants of this form of learning.},
  subject      = {Taufliege},
  language  = {en}
}
@phdthesis{ElHajj2011,
  author    = {El Hajj, Nady},
  title     = {Epimutations in Germ-Cell and Embryo Development: Possible Consequences for Assisted Reproduction},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65995},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Assisted reproductive technologies (ART) emerged in the late 1970's as a therapy for human infertility. Up till now more than 3 million babies have been conceived through ART, demonstrating the safety and efficiency of the technique. Published reports showed an increase in the rate of imprinting disorders (Beckwith Wiedemann Syndrome, Angelman Syndrome, etc.) in babies born after ART. What are the effects imposed through ART and should researchers reassess its safety and implications on the future offspring? Throughout this thesis, I analyzed the methylation patterns of germ cells and embryos to determine whether in vitro maturation and in vitro fertilization have a negative impact on the epigenetic patterns. Furthermore, DNA methylation was compared between sperm of infertile and presumably fertile controls in order to understand whether epigenetic disturbances lead to infertility at the first place. The occurrence of methylation aberrations in germ cells of infertile patients could be transmitted to new-borns and then cause epigenetic disorders. In order to elucidate the imprinting status within single cells, I developed a new technique based on limiting dilution where bisulfite treated DNA is distributed across several wells before amplification. This allowed methylation measurement at the single allele level as well parent of origin detection. In a total of 141 sperm samples from couples undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) including 106 with male factor or combined infertility and 28 with female infertility, I detected a significant correlation between lower quality of semen parameters (sperm count, percentage of abnormal sperm, and percentage of motile sperm) and the rate of imprinting errors. ALU repeats displayed a higher methylation in sperm DNA of patients leading to a pregnancy and live birth, compared to patients in which pregnancy was not achieved or a spontaneous abortion occurred. A discriminant analysis based on ALU methylation allowed correct classification of >70\% of cases. Preliminary data from illumina methylation arrays where more than 27,000 CpGs were analyzed determined that only a single CpG site from the open reading frame C14orf93 was significantly different between the infertile and presumably fertile control group. However, further improvements on data normalization might permit detection of other differentially methylated regions. Comparison of embryos after natural conception, in vitro fertilized embryos from superovulated oocytes, and embryos achieved through fertilization of in vitro cultured oocytes revealed no dramatic effect on the imprinting patterns of Igf2r, H19, and Snrpn. Oocyte cryotop vitrification did not result in a dramatic increase of imprinting mutations in oocytes even though the rate of sporadic methylation errors in single Snrpn CpGs were higher within the in-vitrified group. Collectively, the results I will present within this thesis suggest an increase in the rate of imprinting errors within the germ cells of infertile patients, in addition to a decrease in genome wide methylation of ALU repetitive elements. I did not observe a detrimental effect on the methylation patterns of oocytes and the resulting embryos using in vitro maturation of oocytes and/or standard IVF with in vivo grown superovulated oocytes.},
  subject      = {Reproduktionsmedizin},
  language  = {en}
}
@article{GoetzKoesterWinkleretal.1994,
  author    = {G{\"o}tz, Rudolf and K{\"o}ster, Reinhard and Winkler, Christoph and Raulf, Friedrich and Lottspeich, Friedrich and Schartl, Manfred and Thoenen, Hans},
  title     = {Neurotrophin-6 is a new member of the nerve growth factor family},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61544},
  year      = {1994},
  abstract  = {DURING vertebrale development, many neurons depend for survival and differentiation on their target cells\(^{1-3}\). The best documented mediator of such a retrograde trophic action is the neurotrophin nerve growth factor (NGF)\(^1\). NGF and the other known members of tbe neurotrophin family, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT -3) and neurotrophin-4/5 (NT -4/5) are conserved as distinct genes over large evolutionary distances\(^{4 -6}\). Here we report the cloning of neurotrophin-6 (NT -6), a new member of this family from the teleost fish Xiphophorus. NT -6 distinguishes itself from the other known neurotrophins in that it is not found as a soluble protein in the medium of producing cells. The addition of heparin (but not chondroitin) effects the release of NT -6 from cell surface and extracellular matrix molecules. Recombinant purified NT -6 has a spectrum of actions similar to NGF on chick sympathetic and sensory neurons, albeit with a lower potency. NT -6 is expressed in tbe embryonie valvulla cerebelli; expression persists in some adult tissues. The interaction of NT-6 with heparin-binding molecuJes may modulate its action in the nervous system .},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{MalitschekWittbrodtFischeretal.1994,
  author    = {Malitschek, Barbara and Wittbrodt, Joachim and Fischer, Petra and Lammers, Reiner and Ullrich, Axel and Schartl, Manfred},
  title     = {Autocrine stimulation of the Xmrk receptor tyrosine kinase in Xiphophorus melanoma cells and identification of a source for the physiological ligand},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61551},
  year      = {1994},
  abstract  = {The melanoma·inducing gene of Xiphophorus fish encodes the Xmrk receptor tyrosine kinase. U sing a highly specific antiserum p~oduced against the recombinant receptor expressed with a baculovirus, it is shown that Xmrk is the most abundant phosphotyrosine protein in fish melanoma and thus highly activated in the tumors. Studies on a melanoma cellline revealed that these cells produce an activity that considerably stimulates receptor autophosphorylation. The stimulating activity induces receptor down-regulation and can be depleted from the melanoma cellsupernatant by the immobilized recombinant receptor protein. The fish melanoma cells can thus be considered autocrine tumor cells providing a source for future purification and characterization of the Xmrk ligand.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@phdthesis{Pahl2011,
  author    = {Pahl, Mario},
  title     = {Honeybee Cognition: Aspects of Learning, Memory and Navigation in a Social Insect},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66165},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Honeybees (Apis mellifera) forage on a great variety of plant species, navigate over large distances to crucial resources, and return to communicate the locations of food sources and potential new nest sites to nest mates using a symbolic dance language. In order to achieve this, honeybees have evolved a rich repertoire of adaptive behaviours, some of which were earlier believed to be restricted to vertebrates. In this thesis, I explore the mechanisms involved in honeybee learning, memory, numerical competence and navigation. The findings acquired in this thesis show that honeybees are not the simple reflex automats they were once believed to be. The level of sophistication I found in the bees' memory, their learning ability, their time sense, their numerical competence and their navigational abilities are surprisingly similar to the results obtained in comparable experiments with vertebrates. Thus, we should reconsider the notion that a bigger brain automatically indicates higher intelligence.},
  subject      = {Biene},
  language  = {en}
}
@article{SchmidSchindelinCardonaetal.2010,
  author    = {Schmid, Benjamin and Schindelin, Johannes and Cardona, Albert and Longair, Martin and Heisenberg, Martin},
  title     = {A high-level 3D visualization API for Java and ImageJ},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67851},
  year      = {2010},
  abstract  = {Background: Current imaging methods such as Magnetic Resonance Imaging (MRI), Confocal microscopy, Electron Microscopy (EM) or Selective Plane Illumination Microscopy (SPIM) yield three-dimensional (3D) data sets in need of appropriate computational methods for their analysis. The reconstruction, segmentation and registration are best approached from the 3D representation of the data set. Results: Here we present a platform-independent framework based on Java and Java 3D for accelerated rendering of biological images. Our framework is seamlessly integrated into ImageJ, a free image processing package with a vast collection of community-developed biological image analysis tools. Our framework enriches the ImageJ software libraries with methods that greatly reduce the complexity of developing image analysis tools in an interactive 3D visualization environment. In particular, we provide high-level access to volume rendering, volume editing, surface extraction, and image annotation. The ability to rely on a library that removes the low-level details enables concentrating software development efforts on the algorithm implementation parts. Conclusions: Our framework enables biomedical image software development to be built with 3D visualization capabilities with very little effort. We offer the source code and convenient binary packages along with extensive documentation at http://3dviewer.neurofly.de.},
  subject      = {Visualisierung},
  language  = {en}
}
@article{StollFeldhaarFraunholzetal.2010,
  author    = {Stoll, Sascha and Feldhaar, Heike and Fraunholz, Martin J. and Gross, Roy},
  title     = {Bacteriocyte dynamics during development of a holometabolous insect, the carpenter ant Camponotus floridanus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67950},
  year      = {2010},
  abstract  = {Background: The carpenter ant Camponotus floridanus harbors obligate intracellular mutualistic bacteria (Blochmannia floridanus) in specialized cells, the bacteriocytes, intercalated in their midgut tissue. The diffuse distribution of bacteriocytes over the midgut tissue is in contrast to many other insects carrying endosymbionts in specialized tissues which are often connected to the midgut but form a distinct organ, the bacteriome. C.floridanus is a holometabolous insect which undergoes a complete metamorphosis. During pupal stages a complete restructuring of the inner organs including the digestive tract takes place. So far, nothing was known about maintenance of endosymbionts during this life stage of a holometabolous insect. It was shown previously that the number of Blochmannia increases strongly during metamorphosis. This implicates an important function of Blochmannia in this developmental phase during which the animals are metabolically very active but do not have access to external food resources. Previous experiments have shown a nutritional contribution of the bacteria to host metabolism by production of essential amino acids and urease-mediated nitrogen recycling. In adult hosts the symbiosis appears to degenerate with increasing age of the animals. Results: We investigated the distribution and dynamics of endosymbiotic bacteria and bacteriocytes at different stages during development of the animals from larva to imago by confocal laser scanning microscopy. The number of bacteriocytes in relation to symbiont-free midgut cells varied strongly over different developmental stages. Especially during metamorphosis the relative number of bacteria-filled bacteriocytes increased strongly when the larval midgut epithelium is shed. During this developmental stage the midgut itself became a huge symbiotic organ consisting almost exclusively of cells harboring bacteria. In fact, during this phase some bacteria were also found in midgut cells other than bacteriocytes indicating a cell-invasive capacity of Blochmannia. In adult animals the number of bacteriocytes generally decreased. Conclusions: During the life cycle of the animals the distribution of bacteriocytes and of Blochmannia endosymbionts is remarkably dynamic. Our data show how the endosymbiont is retained within the midgut tissue during metamorphosis thereby ensuring the maintenance of the intracellular endosymbiosis despite a massive reorganization of the midgut tissue. The transformation of the entire midgut into a symbiotic organ during pupal stages underscores the important role of Blochmannia for its host in particular during metamorphosis.},
  subject      = {Camponotus floridanus},
  language  = {en}
}
@article{Helmreich2010,
  author    = {Helmreich, Ernst J. M.},
  title     = {Ways and means of coping with uncertainties of the relationship of the genetic blue print to protein structure and function in the cell},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68006},
  year      = {2010},
  abstract  = {As one of the disciplines of systems biology, proteomics is central to enabling the elucidation of protein function within the cell; furthermore, the question of how to deduce protein structure and function from the genetic readout has gained new significance. This problem is of particular relevance for proteins engaged in cell signalling. In dealing with this question, I shall critically comment on the reliability and predictability of transmission and translation of the genetic blue print into the phenotype, the protein. Based on this information, I will then evaluate the intentions and goals of today's proteomics and gene-networking and appraise their chances of success. Some of the themes commented on in this publication are explored in greater detail with particular emphasis on the historical roots of concepts and techniques in my forthcoming book, published in German: Von Molek{\"u}len zu Zellen. 100 Jahre experimentelle Biologie. Betrachtungen eines Biochemikers},
  subject      = {Genetik},
  language  = {en}
}
@article{LampidisGrossSokolovicetal.1994,
  author    = {Lampidis, Robert and Gross, Roy and Sokolovic, Zeljka and Goebel, Werner and Kreft, J{\"u}rgen},
  title     = {The virulence regulator protein of Listeria ivanovii is highly homologous to PrfA from Listeria monocytogenes and both belong to the Crp-Fnr family of transcription regulators},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60503},
  year      = {1994},
  abstract  = {No abstract available},
  subject      = {Biologie},
  language  = {en}
}
@article{BrehmHaasGoebeletal.1992,
  author    = {Brehm, Klaus and Haas, Albert and Goebel, Werner and Kreft, J{\"u}rgen},
  title     = {A gene encoding a superoxide dismutase of the facultative intracellular bacterium Listeria monocytogenes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60515},
  year      = {1992},
  abstract  = {A gene (Imsod) encoding superoxide dismutase (SOD; EC 1.15.1.1) of the facultative intracellular pathogen, Listeria monocytogenes, was cloned by functional complementation of an SOD-deficient Escherichia coli mutant. The nucleotide sequence was determined and the deduced amino acid (aa) sequence (202 aa) showed close similarity to manganese-containing SOD's from other organisms. Subunits of the recombinant L. monocytogenes SOD (re-SOD) and of both E. coli SODs formed enzymatically active hybrid enzymes in vivo. DNA/DNA-hybridization experiments showed that this type of recombinant re-sod gene is conserved within the genus Listeria.},
  subject      = {Biologie},
  language  = {en}
}
@article{HaasDumbskyKreft1992,
  author    = {Haas, Albert and Dumbsky, Martina and Kreft, J{\"u}rgen},
  title     = {Listeriolysin genes: complete sequence of ilo from Listeria ivanovii and of lso from Listeria seeligeri},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60529},
  year      = {1992},
  abstract  = {The completc DNA scqucnccs coding for thc thiol-activated cytolysins from Listeria ivanovii, ivanolysin 0 (ILO) and for sccligerolysin 0 (LSO) from Listeria seeligeri have been dctermined. Thc deduced amino acid scquences revealed that: (i) the primary translation products comprise 528 (ILO) and 530 (LSO) amino acids. respectively. (ii) ILO contains two cysteines. LSO has a substitution in the conserved cysteine motif.},
  subject      = {Biologie},
  language  = {en}
}
@article{HaasBrehmKreftetal.1991,
  author    = {Haas, Albert and Brehm, Klaus and Kreft, J{\"u}rgen and Goebel, Werner},
  title     = {Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60536},
  year      = {1991},
  abstract  = {A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the grain-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DHSa as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately SO times that of the combined E. coli catalases. The nucleutide sequence was determined, and the deduced amino acid sequence revealed 43.2\% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of tbe L. seeligeri catalase gene.},
  subject      = {Biologie},
  language  = {en}
}
@phdthesis{Winkel2009,
  author    = {Winkel, Karoline},
  title     = {Synaptonemalkomplexprotein SYCP1: Bindungspartner, Polymerisationseigenschaften und evolution{\"a}re Aspekte},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43955},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2009},
  abstract  = {Synaptonemal Komplexe (SC) sind evolution{\"a}r konservierte, meiosespezifische, protein{\"o}se Strukturen, die maßgeblich an Synapsis, Rekombination und Segregation der homologen Chromosomen beteiligt sind. Sie zeigen eine dreigliedrige strickleiter-artige Organisation, die sich aus i) zwei Lateralelementen (LE), an die das Chromatin der Homologen angelagert ist, ii) zahlreichen Transversalfilamenten (TF), welche die LE in einer reißverschlussartigen Weise miteinander verkn{\"u}pfen, und iii) einem zentralen Element (CE) zusammensetzt. Die Hauptproteinkomponenten der S{\"a}uger-SC sind das Transversalfilamentprotein SYCP1 und die Lateralelementproteine SYCP2 und SYCP3. Wie sich die SC-Struktur zusammenf{\"u}gt war bisher nur wenig verstanden; es war nicht bekannt wie die TF innerhalb der LE-Strukturen verankert sind und dabei die homologen Chromosomen verkn{\"u}pfen. Aufgrund dessen wurde die Interaktion zwischen den Proteinen SYCP1 und SYCP2 untersucht. Mit der Hilfe verschiedenster Interaktionssysteme konnte gezeigt werden, dass der C-Terminus von SYCP1 mit SYCP2 interagieren kann. Aufgrund der Bindungsf{\"a}higkeit zu beiden Proteinen, SYCP1 und SYCP3, kann angenommen werden, dass SYCP2 als Linker zwischen diesen Proteinen fungiert und somit m{\"o}glicherweise das fehlende Bindungsglied zwischen den Lateralelementen und Transversalfilamenten darstellt. Obwohl die SC-Struktur in der Evolution hochkonserviert ist, schien dies nicht f{\"u}r seine Protein-Untereinheiten zuzutreffen. Um die Struktur und Funktion des SC besser verstehen zu k{\"o}nnen, wurde ein Vergleich zwischen den orthologen SYCP1 Proteinen der evolution{\"a}r entfernten Spezies Ratte und Medaka erstellt. Abgesehen von den erheblichen Sequenzunterschieden die sich in 450 Millionen Jahren der Evolution angeh{\"a}uft haben, traten zwei bisher nicht identifizierte Sequenzmotive hervor, CM1 und CM2, die hochgradig konserviert sind. Anhand dieser Motive konnte in Datenbankanalysen erstmals ein Protein in Hydra vulgaris nachgewiesen werden, bei dem es sich um das orthologe Protein von SYCP1 handeln k{\"o}nnte. Im Vergleich mit dem SYCP1 der Ratte zeigten die Proteine aus Medaka und Hydra, neben den hoch konservierten CM1 und CM2, vergleichbare Dom{\"a}nenorganisationen und im heterologen System zudem sehr {\"a}hnliche Polymerisationseigenschaften. Diese Ergebnisse sprechen f{\"u}r eine evolution{\"a}re Konservierung von SYCP1.},
  subject      = {Meiose},
  language  = {de}
}
@article{KreftBurgerGoebel1983,
  author    = {Kreft, J{\"u}rgen and Burger, Klaus J. and Goebel, Werner},
  title     = {Expression of antibiotic resistance genes from Escherichia coli in Bacillus subtilis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60600},
  year      = {1983},
  abstract  = {Bifunctional recombinant plasmids were constructed, comprised of the E. coli vectors pBR322, pBR325 and pACYC184 and different plasmids from Gram-positive bacteria, e.g. pBSU161-1 of B. subtilis and pUB110 and pC221 of S. aureus. The beta-lactamase (bla) gene and the chloramphenicol acetyltransferase (cat) gene from the E. coli plasmids were not transcribed and therefore not expressed in B. subtilis. However, tetracycline resistance from the E. coli plasmids was expressed in B. subtilis. Transcription of the tetracycline resistance gene(s) started in B. subtilis at or near the original E. coli promoter, the sequence of which is almost identical with the sequence recognized by σ<sup>55</sup> of B. subtilis RNA polymerase.},
  subject      = {Biologie},
  language  = {en}
}
@article{KreftBergerHaertleinetal.1983,
  author    = {Kreft, J{\"u}rgen and Berger, Harald and H{\"a}rtlein, Michael and M{\"u}ller, Bodo and Weidinger, Gerhard and Goebel, Werner},
  title     = {Cloning and expression in Escherichia coli and Bacillus subtilis of the hemolysin (cereolysin) determinant from Bacillus cereus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60596},
  year      = {1983},
  abstract  = {From a cosmid gene bank of Bacillus cereus GP4 in Escherichia coli we isolated clones which, after several days of incubation, formed hemolysis zones on erythrocyte agar plates. These clones contained recombinant cosmids with B. cereus DNA insertions of varying lengths which shared some common restriction fragments. The smallest insertionwas recloned as aPstl fragment into pJKK3-1, a shuttle vector which rep{\"u}cates in Bacillus subtilis and E. coli. When this recombinant plasmid (pJKK3-1 hly-1) was transformed into E. coli, it caused hemolysis on erythrocyte agar plates, but in liquid assays no extemal or intemal hemolytic activity could be detected with the E. coli transformants. B. subtilis carrying the same plasmid exhibited hemolytic activity at Ievels comparable to those ofthe B. cereus donor strain. The hemolysin produced in B. subtilis seemed to be indistinguishable from cereolysin in its sensitivity to cholesterol, activation by dithiothreitol, and inactivation by antibodies raised against cereolysin. When the recombinant DNA carrying the cereolysin gene was used as a probe in hybridization experiments with chromosomal DNA from a streptolysin 0-producing strain of Streptococcus pyogenes or from {\"u}steriolysin-producing strains of Usteria monoeytogenes, no positive hybridization signals were obtained. These data soggest that the genes for these three SH-activated cytolysins do not have extended sequence homology.},
  subject      = {Biologie},
  language  = {en}
}
@article{GesslerHameisterHenryetal.1990,
  author    = {Gessler, Manfred and Hameister, H. and Henry, I. and Junien, C. and Braun, T. and Arnold, H. H.},
  title     = {The human MyoD1 (MYF3) gene maps on the short arm of chromosome 11 but is not associated with the WAGR locus or the region for the Beckwith-Wiedemann syndrome},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59221},
  year      = {1990},
  abstract  = {The human gene encoding the myogenic determination factor myf3 (mouse MyoD1) has been mapped to the short arm of chromosome 11. Analysis of several somatic cell hybrids containing various derivatives with deletions or translocations revealed that the human MyoD (MYF3) gene is not associated with the WAGR locus at chromosomal band 11pl3 nor with the loss of the heterozygosity region at 11p15.5 related to the Beckwith-Wiedemann syndrome. Subregional mapping by in situ hybridization with an myf3 specific probe shows that the gene resides at the chromosomal band llp14, possibly at llp14.3.},
  subject      = {Biochemie},
  language  = {en}
}
@article{vanHeyningenBickmoreSeawrightetal.1990,
  author    = {van Heyningen, V. and Bickmore, W. A. and Seawright, A. and Fletcher, J. M. and Maule, J. and Fekete, G. and Gessler, Manfred and Bruns, G. A. and Huerre-Jeanpierre, C. and Junien, C.},
  title     = {Role for the Wilms tumor gene in genital development?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59238},
  year      = {1990},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{GesslerBruns1989,
  author    = {Gessler, Manfred and Bruns, G. A. P.},
  title     = {A physical map around the WAGR complex on the short arm of chromosome 11},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59246},
  year      = {1989},
  abstract  = {A long-range restriction map of part of the short arm of ehromosome 11 including the WAGR region has been constructed using pulsed-field gel electrophoresis and a number of infrequently cutting restriction enzymes. A total of 15.4 Mbp has been mapped in detall, extending from proximal 11p14 to the distal part of 11p12. The map localizes 35 different DNA probes and reveals at least nine areas with features eharaeteristle of BTF islands, some of which may be candidates for the different loci underlying the phenotype of the WAGR syndrome. This map will furthermore allow screening of DNA from individuals with WAGR-related phenotypes and from Wilms tumors for associated chromosomal rearrangements.},
  subject      = {Biochemie},
  language  = {en}
}
@article{GesslerThomasCouillinetal.1989,
  author    = {Gessler, Manfred and Thomas, G. H. and Couillin, P. and Junien, C. and McGillivray, B. C. and Hayden, M. and Jaschek, G. and Bruns, G. A.},
  title     = {A deletion map of the WAGR region on chromosome II},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59255},
  year      = {1989},
  abstract  = {The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals. We have utilized 31 DNA probes which map to the WAGR deletion region, together with six reference loci and 13 WAGR-related deletions, to subdivide this area into 16 intervals. Specific intervals have been correlated with phenotypic features, leading to the identification of individual subregions for the aniridia and Wilms tumor loci. Delineation, by specific probes, of multiple intervals above and below the critical region and of five intervals within the overlap area provides a framework map for molecular characterization of WAGR gene loci and of deletion boundary regions.},
  subject      = {Biochemie},
  language  = {en}
}
@article{KreftFunkeHaasetal.1989,
  author    = {Kreft, J{\"u}rgen and Funke, Dorothee and Haas, Albert and Lottspeich, Friedrich and Goebel, Werner},
  title     = {Production, purification and characterization of hemolysins from Listeria ivanovii and Listeria monocytogenes Sv4b.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60545},
  year      = {1989},
  abstract  = {In culture supematants of both Listeria ivanovii and Listeria monocytogenes Sv4b, for the first time a hemolysin of molecular weight 58 kDa was identified, which had all the characteristics of an SH-activated cytolysin, and which was therefore identified as Iisteriolysin 0 (LLO). In the case of L. ivanovii a second major supematant protein of molecular weight 24 kDa co-purified with LLO. However, the function of this protein has to be determined. In culture supematants of L. ivanovii a sphingomyelinase and a Iecithinase activity could be detected, both enzymatic activities together contributing to the pronounced hemolysis caused by L. ivanovii. The N-tenninal amino acid sequences of LLO and the 24 kDa from L. ivanovii are shown.},
  subject      = {Biologie},
  language  = {en}
}
@article{GoebelChakrabortyKreft1988,
  author    = {Goebel, Werner and Chakraborty, T. and Kreft, J{\"u}rgen},
  title     = {Bacterial hemolysins as virulence factors},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60553},
  year      = {1988},
  abstract  = {No abstract available},
  subject      = {Biologie},
  language  = {en}
}
@article{GoebelKathariouKuhnetal.1988,
  author    = {Goebel, Werner and Kathariou, S. and Kuhn, M. and Sokolovic, Z. and Kreft, J{\"u}rgen and K{\"o}hler, S. and Funke, D. and Chakraborty, T. and Leimeister-W{\"a}chter, M.},
  title     = {Hemolysin from Listeria-biochemistry, genetics and function in pathogenesis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60563},
  year      = {1988},
  abstract  = {No abstract available},
  subject      = {Biologie},
  language  = {en}
}
@article{SchueleinKreftGonskietal.1991,
  author    = {Sch{\"u}lein, Ralf and Kreft, J{\"u}rgen and Gonski, Sigrid and Goebel, Werner},
  title     = {Preprosubtilisin Carlsberg processing and secretion is blocked after deletion of amino acids 97-101 in the mature part of the enzyme},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60577},
  year      = {1991},
  abstract  = {During an investigation into the substrate specificity and processing of subtilisin Carlsberg from Bacillus licheniformis, two major independent findings were made: (i) as has been shown previously, a stretch of five amino acids (residues 97-101 of the mature enzyme) that loops out into the binding cleft is involved in substrate binding by subtilisin Carlsberg. In order to see whether this loop element also determines substrate specificity, the coding region for these five amino acids was deleted from the cloned gene for subtilisin Carlsberg by site-directed mutagenesis. Unexpectedly the resulting mutant preproenzyme (P42c, M<sub>r</sub>=42 kDa) was not processed to the mature form (M<sub>r</sub> = 30 kDa) and was not released into the medium by a proteasedeficient B. subtilis host strain; rather, it accumulated in the cell membrane. This result demonstrates that the integrity of this loop element, which is very distant from the processing cleavage sites in the preproenzyme, is required for secretion of subtilisin Carlsberg. (ii) In culture supernatants from B. subtilis harbouring the cloned wild-type subtilisin Carlsberg gene the transient appearance (at 0-3 h after onset of stationary phase) of a processing intermediate (P38c, M<sub>r</sub> = 38 kDa) oftbis protease could be demonstrated. P38c very probably represents a genuine proform of subtilisin Carlsberg.},
  subject      = {Biologie},
  language  = {en}
}
@article{GilmoreCruzRodzLeimeisterWaechteretal.1989,
  author    = {Gilmore, Michael S. and Cruz-Rodz, Armando L. and Leimeister-W{\"a}chter, Michaela and Kreft, J{\"u}rgen and Goebel, Werner},
  title     = {A Bacillus cereus cytolytic determinant, cereolysin AB, which comprises the phospholipase C and sphingomyelinase genes: nucleotide sequence and genetic linkage},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60588},
  year      = {1989},
  abstract  = {A cloned cytolytic determinant from the genome of Bacillus cereus GP-4 has been characterized at the molecular Ievel. Nucleotide sequence determination revealed the presence of two open reading frames. 8oth open reading frames were found by deletion and complementation analysis to be necessary for expression of the hemolytic phenotype by Bacillus subtilis and Escherichia coli hosts. The 5' open reading frame was found to be nearly identical to a recently reported phospholipase C gene derived from a mutant B. cereus strain which overexpresses the respective protein, and it conferred a lecithinase-positive phenotype to the B. subtilis host. The 3' open reading frame encoded a sphingomyelinase. The two tandemly encoded activities, phospholipase C and sphingomyelinase, constitute a biologically functional cytolytic determinant of B. cereus termed cereolysin AB.},
  subject      = {Biologie},
  language  = {en}
}
@article{HaertleinSchiesslWagneretal.1983,
  author    = {H{\"a}rtlein, Michael and Schiessl, Sigrid and Wagner, Wilma and Rdest, Ursula and Kreft, J{\"u}rgen and Goebel, Werner},
  title     = {Transport of hemolysin by Escherichia coli},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60619},
  year      = {1983},
  abstract  = {No abstract available},
  subject      = {Biologie},
  language  = {en}
}
@article{GoebelKreft1972,
  author    = {Goebel, Werner and Kreft, J{\"u}rgen},
  title     = {Accumulation of replicative intermediates and catenated forms of the colicinogenic factor E\(_1\) in E. coli during the replication at elevated temperatures},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60625},
  year      = {1972},
  abstract  = {No abstract available},
  subject      = {Biologie},
  language  = {en}
}
@article{PoulatMorinKonigetal.1993,
  author    = {Poulat, F. and Morin, D. and Konig, A. and Brun, P. and Giltay, J. and Sultan, C. and Dumas, R. and Gessler, Manfred and Berta, P.},
  title     = {Distinct molecular origins for Denys-Drash and Frasier syndromes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59172},
  year      = {1993},
  abstract  = {The direct involvment of the Wilm's tumor suppressor gene (WTl) in Denys-Drash syndrome through mutations within exons 8 or 9 has recently been established. The absence of such alterations in three patients with Frasier syndrome provides a molecular basis for distinguishing these two syndromes that are associated with streak gonads, pseudohermaphroditism and renal failure.},
  subject      = {Biochemie},
  language  = {en}
}
@article{GesslerGrupeGrzeschiketal.1992,
  author    = {Gessler, Manfred and Grupe, Andrew and Grzeschik, Karl-Heinz and Pongs, Olaf},
  title     = {The potassium channel gene HK1 maps to human chromosome 11p14.1, close to the FSHB gene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59184},
  year      = {1992},
  abstract  = {Transiently activating (A-type) potassium (K) channels are important regulators of action potential and action potential firing frequencies. HK1 designates the firsthuman cDNA that is highly homologous to the rat RCK4 cDNA that codes for an A-type K-channel. The HK1 channel is expressed in heart. By somatic cell hybrid analysis, the HK1 gene has been assigned to human chromosome 11p13-pl4, the WAGR deletion region (Wilms tumor, aniridia, genito-urinary abnormalities and mental retardation). Subsequent pulsed field gel (PFG) analysis and comparison with the well-established PFG map of this region localized the gene to 11p14, 200-600 kb telomeric to the FSHB gene.},
  subject      = {Biochemie},
  language  = {en}
}
@article{GesslerKoenigBruns1992,
  author    = {Gessler, Manfred and K{\"o}nig, A. and Bruns, G. A. P.},
  title     = {The genomic organization and expression of the WT1 gene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59195},
  year      = {1992},
  abstract  = {The Wilms tumor gene WTl, a proposed tumor suppressor gene, has been identifled based on its location within a homozygous deletion found in tumor tissue. The gene encodes a putative transcription factor containing a Cys/His zinc finger domain. The critical homozygous deletions, however, are rarely seen, suggesting that in many cases the gene may be inactivated by more subtle alterations. To facilitate the seareh for smaller deletions and point mutations we have established the genomic organization of the WTl gene and have determined the sequence of all 10 exons and flanking intron DNA. The pattern of alternative splicing in two regions has been characterized in detail. These results will form the basis for future studies of mutant alleles at this locus.},
  subject      = {Biochemie},
  language  = {en}
}
@article{WolfKlugHackenbergetal.1992,
  author    = {Wolf, Markus and Klug, J{\"o}rg and Hackenberg, Reinhard and Gessler, Manfred and Grzeschik, Karl-Heinz and Beato, Miguel and Suske, Guntram},
  title     = {Human CC10, the homologue of rabbit uteroglobin: genomic cloning, chromosomal localization and expression in endometrial cell lines},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59206},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{VortkampThiasGessleretal.1991,
  author    = {Vortkamp, A. and Thias, U. and Gessler, Manfred and Rosenkranz, W. and Kroisel, P. M. and Tommerup, N. and Kruger, G. and Gotz, J. and Pelz, L. and Grzeschik, Karl-Heinz},
  title     = {A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59217},
  year      = {1991},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@phdthesis{Grohmann2010,
  author    = {Grohmann, Constanze},
  title     = {Termite mediated heterogeneity of soil and vegetation patternsin a semi-arid savanna ecosystem in Namibia},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-54318},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Termites are the most important soil ecosystem engineers of semi-arid and arid habitats. They enhance decomposition processes as well as the subsequent mineralisation of nutrients by bacteria and fungi. Through their construction of galleries, nests and mounds, they promote soil turnover and influence the distribution of nutrients and also alter texture and hydrological properties of soils, thereby affecting the heterogeneity of their ecosystem. The main aim of the present thesis was to define the impact of termites on ecosys-tem functioning in a semi-arid ecosystem. In a baseline study, I assessed the diversity of termite taxa in relation to the amount of precipitation, the vegetation patterns and the land use systems at several sites in Namibia. Subsequently, I focussed on a species that is highly abundant in many African savannas, the fungus growing and mound building species Macro-termes michaelseni (Sj{\"o}stedt, 1914). I asked how this species influences the spatial hetero-geneity of soil and vegetation patterns. From repeated samplings at 13 sites in Namibia, I obtained 17 termite taxa of 15 genera. While the type of land use seems to have a minor effect on the termite fauna, the mean annual precipitation explained 96\% and the Simpson index of vascular plant diversity 81\% of the variation in taxa diversity. The number of termite taxa increased with both of these explanation variables. In contrast to former studies on Macrotermes mounds in several regions of Africa that I reviewed, soil analyses from M. michaelseni mounds in the central Namibian savanna revealed that they contain much higher nitrogen contents when compared to their parent material. Further analyses revealed that nitrate forms a major component of the nitrogen content in termite mounds. As nitrate solves easily in water, evaporation processes are most probably responsible for the transport of solved nitrates to the mound surface and their accumulation there. The analysed mounds in central Namibia contained higher sand propor-tions compared to the mounds of the former studies. Through the higher percentage of coarse and middle sized pores, water moves more easily in sandy soils compared to more clayey soils. In consequence, evaporation-driven nitrate accumulation can occur in the studied mounds at high rates. Hochgerechnet auf den Gesamtumfang der H{\"u}gel bedeckte das pro Jahr von einem bewohnten H{\"u}gel erodierte Material theoretisch einen 1 m breiten Kreisring um den Schwemmkegel des H{\"u}gels 2,4 mm hoch. Der entsprechende Wert f{\"u}r unbewohnte H{\"u}gel betrug 1,0 mm. To assess the amount of soil that erodes from termite mounds, I fastened four strong, 65 cm wide plastic bags at 14 mounds each and collected the soil that eroded during five rainfall events. Projected to the total mound circumference, the amount of soil eroded covers theoretically a 1 m wide circular ring around the pediment of an inhabited mound up to a height of 2.4 mm per year. For uninhabited mounds, the height of this soil layer would be 1.0 mm. Per hectare, roughly 245 kg eroded per year from the mounds. However, as the erosion rate depends on several factors such as rainfall intensity, soil texture and point of time within the rainy season, this is only a vague estimate. In order to determine up to which distance the soil erosion from the mounds still influences the chemical characteristics of the adjacent topsoil, I took samples from depth of 0-10 cm at 1, 5 and 25 m distances, respectively, from four different mounds and from the mounds themselves. The non-metric multidimensional scaling of the soil properties showed strong differences between mound and off-mound samples. Soil characteristics within the samples from the mounds did not differ largely. Similarly, I found no strong differences between the samples taken from the different distances from the mound. From these results I conclude that through the construction of foraging galleries and sheetings (soil constructions with which some termite species cover their food items), the soil eroding from termite mounds is quickly mixed with deeper soil layers. In consequence, mound material does not accumulate in the mound's vicinity. In order to reveal how plant growth is influenced by termite mound material, we assessed the number of grass and herb individuals as well as the biomass of plants growing in situ on the base of mounds compared to adjacent sites. While the numbers of both grass and herb individuals were significantly lower compared to adjacent sites, the total biomass of plants growing on the base of mounds was significantly higher. Reverse results were obtained by pot experiments with radish (Raphanus sativus subsp. sativus) and sorghum (Sorghum sp.) growth. Both species grew significantly weaker on mound soil compared to adjacent soil. The contradictory results concerning the biomass of in situ and pot experi-ments are most probably caused by the disturbance of the original soil structure during the potting process. The material was subsequently compacted through watering the plants. In contrast, Macrotermes mounds are pervaded by many macropores which seem to be essential for the plant roots to penetrate the soil. In the last part of this thesis, I posed the question how mounds of M. michaelseni are distributed and what factors might be responsible for this pattern. Former studies showed that mound size is correlated with the size of its inhabiting colony. With several multi-scale analyses, I revealed that larger inhabited mounds were regularly distributed. Additionally, mounds which were closer together tended to be smaller than on average. This indicates that intraspecific competition controls the distribution and size of colonies and their mounds. Former studies concerning Odontotermes mounds substantiated that they are local hotspots of primary productivity and animal abundance. Based on these findings, simulations revealed that a regular distribution of these mounds leads to a greater ecosystem-wide productivity compared to a random arrangement. As in the present study, plant biomass was higher at the mounds compared to off-mound sites, this might hold true for M. michaelseni mounds. From the results of this thesis, I draw the conclusion that through their mound building activities, M. michaelseni strongly influences the distribution patterns of soil nutrients within the central Namibian savanna. These termites create sharp contrasts in nutrient levels and vegetation patterns between mound soils and off-mound soils and enhance the heterogeneity of their habitats. Former studies revealed that habitat hetero-geneity is important in generating species diversity and species richness in turn is correlated positively with biomass production and positively affects ecosystem services. In conclusion, the present thesis underlines the importance of M. michaelseni for ecosystem functioning of the central Namibian savanna.},
  subject      = {Termiten},
  language  = {en}
}
@phdthesis{Fischer2014,
  author    = {Fischer, Peter},
  title     = {Untersuchungen zum Einfluss der Anzahl primordialer Keimzellen auf die Geschlechtsbestimmung von Medaka, Oryzias latipes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-106846},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Die primordialen Keimzellen (PGCs) sind die einzigen Zellen des Embryos, die die genetische Information von einer Generation an die n{\"a}chste weiter geben k{\"o}nnen. Es wurde gezeigt, dass in allen bislang untersuchten Knochenfischen die Anzahl der Urgeschlechtszellen w{\"a}hrend der Embryonalentwicklung der erste sichtbare Unterschied zwischen M{\"a}nnchen und Weibchen ist. Daraus ergibt sich die Frage, ob die Anzahl der primordialen Keimzellen das Geschlecht bestimmt, oder ob die somatischen Zellen je nach sexueller Identit{\"a}t die Urgeschlechtszellen zur Proliferation anregen. Um zu untersuchen, wie die Anzahl der Urgeschlechtszellen mit der Geschlechtsdetermination zusammenh{\"a}ngt, habe ich in dieser Arbeit die Anzahl der Urgeschlechtszellen manipuliert und deren Schicksal im Verlauf der Embryonalentwicklung verfolgt. Weiterhin untersuchte ich, in wieweit die Temperatur einen Einfluss auf die Geschlechtsbestimmung hat und ob sie Auswirkungen auf die Anzahl und die Wanderung der Urgeschlechtszellen hat beim Medaka hat. Durch meine Experimente, in denen ich die Fische w{\"a}hrend der Embryonalentwicklung bei verschiedenen Temperaturen hielt, konnte ich zeigen, dass beim Medaka der genetische Geschlechtsbestimmungsmechanismus durch erh{\"o}hte Temperatur {\"u}berschrieben werden kann. Die Temperaturerh{\"o}hung in der Embryonalentwicklung f{\"u}hrt zu einer Weibchen­-zu­-M{\"a}nnchen Geschlechtsumkehr. Dabei wird die Anzahl der primordialen Keimzellen im Vergleich zu den Kontrollen reduziert. Zudem wird durch die h{\"o}here Temperatur das autosomale dmrt1a viel fr{\"u}her angeschaltet, wa sauf einen alternativenSignalweg deutet, der die m{\"a}nnliche Geschlechtsentwicklung in XX geschlechtsumgewandelten Tieren steuert.},
  subject      = {Geschlechtsbestimmung},
  language  = {de}
}
@phdthesis{Zdzieblo2014,
  author    = {Zdzieblo, Daniela},
  title     = {Das Polycomb group Protein PCGF6 ist ein neuer und essentieller Faktor der iPS Reprogrammierung und kann in Kombination mit Oct4, Klf4 und c-Myc den Transkriptionsfaktor Sox2 ersetzen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-106870},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Embryonale Stammzellen (ESCs) sind durch zwei charakteristische Eigenschaften definiert. Neben einer kontinuierlichen Selbsterneuerungskapazit{\"a}t weisen ESCs die F{\"a}higkeit auf, in alle Zelltypen der drei Keimbl{\"a}tter differenzieren zu k{\"o}nnen. Diese Eigenschaften werden unter anderem durch ein Netzwerk wichtiger Pluripotenzfaktoren als auch durch epigenetische Mechanismen reguliert, welche die Transkription von Pluripotenz- und Differenzierungsgenen kontrollieren. In murinen ESCs sind an der Repression von Differenzierungsgenen auch Polycomb group (PcG) Proteine beteiligt. Diese Proteine bauen zwei Chromatin-modifizierende Komplexe auf, die als Polycomb repressive complex 1 bzw. 2 (PRC1 bzw. PRC2) bezeichnet werden. Nach dem klassischen Modell der Polycombfunktion, katalysieren PRC1 und PRC2 gemeinsam zwei charakteristische Histonmodifikationen, die zur Repression PRC-spezifischer Zielgene beitragen. Zahlreiche Studien in den letzten Jahren belegen, dass der Proteinaufbau der PRC1 Komplexe stark variieren kann, wobei die Familie der Polycomb group RING finger (Pcgf) Proteine eine wichtige Rolle spielt. In diesem Zusammenhang definieren einzelne Pcgf Paraloge (Pcgf1 - 6) verschiedene PRC1 Varianten (PRC1.1 - 1.6), die Komplex-spezifische Bindestellen im Genom aufweisen. Diese Erkenntnisse lassen auf unterschiedliche Mechanismen der PRC1 Varianten und Pcgf Paralog-spezifische Funktionen schließen, die zum jetzigen Zeitpunkt nur wenig erforscht sind. F{\"u}r manche Pcgf Paraloge sind wichtige Rollen in verschiedenen Stammzelltypen und w{\"a}hrend der iPS Reprogrammierung bekannt. Pcgf1 (Nspc1), Pcgf2 (Mel18) und Pcgf4 (Bmi1) zeigen eine Funktion in verschiedenen adulten Stammzellen. Pcgf4 spielt dar{\"u}ber hinaus eine wichtige Rolle in der murinen iPS Reprogrammierung. F{\"u}r Pcgf6 (Mblr) wird eine Pluripotenz-assoziierte Funktion angenommen, denn Pcgf6 ist das einzige Pcgf Paralog, das eine erh{\"o}hte Expression in murinen ESCs aufweist, die jedoch im Verlauf der ESC-Differenzierung absinkt. Außerdem zeigen murine Pcgf6 KD ESCs eine verminderte Expression der Pluripotenzgene Oct4, Sox2 und Nanog, eine De-Repression mesodermaler und Testes-spezifischer Gene als auch eine erh{\"o}hte Tendenz zur h{\"a}matopoetischen Differenzierung. Wie genau Pcgf6 an der Regulation dieser Prozesse in murinen ESCs beteiligt ist, ist nicht bekannt. In der hier vorliegenden Dissertation wurde die Funktion von Pcgf6 in der murinen iPS Reprogrammierung untersucht. Da bereits f{\"u}r Pcgf4 eine Rolle in der Reprogrammierung somatischer Zellen gezeigt wurde und Pcgf6 eine erh{\"o}hte Expression in ESCs aufweist, wurde auch f{\"u}r Pcgf6 eine Funktion in der iPS Reprogrammierung angenommen. Zun{\"a}chst konnte in dieser Arbeit gezeigt werden, dass Pcgf6 w{\"a}hrend der iPS Reprogrammierung verst{\"a}rkt exprimiert wird und in iPS Zellen eine ESC-{\"a}hnliche Expression aufweist. Dar{\"u}ber hinaus konnte Pcgf6 in Kombination mit Oct4, Klf4 und c-Myc spezifisch den Transkriptionsfaktor Sox2 in der iPS Reprogrammierung ersetzen. Zudem wurden f{\"u}r OPKM-induzierte iPS Zellen charakteristische Eigenschaften pluripotenter Zellen nachgewiesen. Außerdem konnte eine Rolle von Pcgf6 als Enhancer-Faktor f{\"u}r die iPS Reprogrammierung ausgeschlossen werden, da die {\"U}berexpression von Pcgf6 zusammen mit den OSKM Faktoren keine additiven Effekte auf die Reprogrammierungseffizienz erzielte. Im Gegensatz dazu f{\"u}hrte der Knockdown (KD) von Pcgf6 in embryonalen Mausfibroblasten (MEFs) zu verminderten Effizienzen nach OSKM Reprogrammierung. Dar{\"u}ber hinaus handelte es sich bei der Mehrheit der AP+ Kolonien, die unter Pcgf6 KD Konditionen entstanden, um partiell-reprogrammierte iPS Zellen. Zusammengefasst zeigen die Ergebnisse der hier vorliegenden Arbeit, dass Pcgf6 ein neuer und essentieller Faktor der iPS Reprogrammierung ist, der in Kombination mit Oct4, Klf4 und c-Myc spezifisch den Transkriptionsfaktor Sox2 ersetzen kann.},
  subject      = {Stammzelle},
  language  = {de}
}
@phdthesis{Kaiser2014,
  author    = {Kaiser, Dorkas},
  title     = {Termites and ants in BURKINA FASO (WEST AFRICA): taxonomic and functional diversity along land-use gradients; ecosystem services of termites in the traditional ZA{\"I} SYSTEM},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107001},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {The consequences of habitat change for human well-being are assumed to be especially extreme in Burkina Faso. The country is located in a highly drought-sensitive zone of West Africa, and small-scale subsistence farmers may be especially affected if losses of biodiversity lead to changes in ecosystem functioning; many depend on more or less degraded lands for agricultural production. The overall aim of the present thesis consequently was to characterize the functional traits of soil-organisms which are crucial for a productive and balanced soil environment in the study region - termites and ants. They are true ecosystem engineers whose activity alters the habitat. Through soil-turnover in the course of constructing biogenic structures of varying size and nature (mounds, nests, galleries, soil-sheetings, foraging-holes), they bioturbate huge amounts of soil masses and exert massive effects on soil structure, positively influencing the fertility, stability, aeration and water infiltration rate into soils; and they provide habitats for other species. In sub-Saharan Africa, ants and termites are the only active soil macrofauna during the long dry season; in the sub-Sahel zone of Burkina Faso, termites even represent the only active, quantitatively remarkable decomposers all year round. Since no information was available about the actual diversity of the focal arthropods, I divided the thesis in two main parts: In the first part, a baseline study, I assessed the local termite and ant fauna, and investigated their quantitative and qualitative response to changing habitat parameters resulting from increasing human impact ('functional response traits'). In the second and applied part, I addressed the impact of the biogenic structures which are important for the restoration of degraded soils ('functional effect traits'). Two traditional agricultural systems characteristic for the study region were selected. Each system represented a land-use intensification gradient comprising four distinct habitats now differing in the magnitude of human intervention but formerly having the same initial state. The first disturbance gradient, the temporal cross-section of a traditional soil water conservation technique to restore degraded heavily encrusted, barren soil named Za{\"i} in Ouahigouya (Yatenga province, sub-Sahel zone); the second disturbance gradient, an agriculture type using crop rotation and fallow as nutrient management techniques near Fada N'Gourma (Gourma province, North-Sudanese zone). No standard protocol existed for the assessment of termite and ant diversity in semi-arid (agro-) ecosystems; two widely accepted standard protocols provided the basis for the newly revised and combined rapid assessment protocol 'RAP': the ALL protocol for leaf litter ants of Agosti and Alonso (2000), and the transect protocol for termites in tropical forests of Jones and Eggleton (2000). In each study site, three to four replicate transects were conducted during the rainy seasons (2004—2008). The RAP-protocol turned out to be very effective to characterize, compare and monitor the taxonomic and functional diversity of termites and ants; between 70\% and 90\% of the estimated total species richness were collected on all levels (transects, habitats, regions). Together in both regions, 65 ant species (25 genera) and 39 termite species (13 genera) were collected. These findings represent the first records for Burkina Faso. The data indicate a high sensitivity of termites and ants to land-use intensification. The diversity strongly decreased with increasing anthropogenic impact in the North-Sudan region. In total, 53 ant species (23 genera) and 31 termite species (12 genera) were found. Very promising results concerning the recovery potential of the soil-arthropods' diversity were gathered in the Za{\"i} system. The diversity of both taxa strongly increased with increasing habitat rehabilitation - in total, 41 ant species (16 genera) and 33 termite species (11 genera) were collected. For both taxa significant differences could be noted in the shape of the density variations along the gradient. For instance termites: Fungus-growers showed the greatest adaptability to different management practices. The greatest variations between the habitats were observed in soil and grass-feeding termites. Whole functional groups were missing in heavily impacted habitats, e.g. soil-, grass-, and wood-feeders were absent in the degraded site in the sub-Sahel zone. Several environmental parameters could be identified which significantly explained a great part of the variations in the composition of the arthropods' communities; they indicate the importance of the habitats' structural complexity (vegetation structure) and concomitant effects on diurnal temperature and moisture fluctuations, the availability of food sources, and the soil-structure. The diversity of termites in the sub-Sahel region was strongly correlated with the crown-cover percentages, the topsoils' sand-content, and the availability of litter; in the North-Sudan region with the cumulated woody plant basal area, the topsoils' clay- and organic matter-content. The parameters identified for ant communities in the Za{\"i} system, were the height of trees, the topsoils' clay-content and air humidity; in the North-Sudan region the habitats' crown-cover percentages, the quantity of litter and again the height of trees. In the second part of the thesis, I first rapidly assessed the (natural) variations in the amount of epigeal soil-structures along the two disturbance gradients in order to judge the relative importance of termites and ants for soil-turnover. The results illustrated impressively that a) in all study sites, termites were the main bioturbators while ant structures were of minor importance for soil turn-over; b) earthworms and grass-feeding termites contributed significantly to soil turn-over in the more humid North-Sudan region; and c) the bioturbated soil mass varied between seasons and years, however, the relative importance of the different taxa seemed to be fairly constant. In the sub-Sahel zone, fungus-growing Odontotermes and Macrotermes species fully take over the important function of bioturbation, leading to the transport of huge amounts of fine-textured soil material to the surface; with increasing habitat restoration, coarse fragments decreased in the upper horizons and became concentrated deeper along the soil profile. Consequently, in the applied part, I concentrated on the bioturbation activity of fungus-growing termites in the four main stages of the Za{\"i} system: crusted bare soil (initial stage), millet field, young and old forest. In each of the four Za{\"i} sites nine experimental blocks (each comprising four plots of 1m2) were used to stimulate the foraging activity of fungus-growing termites with different, locally available organic materials (Aristida kerstingii hay, Bombax costatum wooden blocks, compost and a control without any organic amendment). The experiment was conducted twice for the duration of four weeks (rainy season 2005, dry season 2006). The plots were regularly checked and the increase of the area covered by sheetings chronologically followed. After four weeks a) all sheeting-soil was collected, air dried and separately weighed according to the different genera, and b) the foraging-holes were counted and their diameter measured. Additionally, c) ponded water infiltration was measured in selected plots, and d) the physicochemical properties of sheeting-soil were analyzed. In case of complete consumption of the offered hay during the experimental 4-weeks-duration, the same procedure (a, b) was followed before adding new hay to the respective plot. The comparison between the different plots, sites and seasons revealed clearly that hay was the most attractive bait; for each gram of hay removed, Odontotermes brought about 12 g soil to the surface, Macrotermes 4 g. Odontotermes was the only genus attracted by organic material to the degraded area, and was therefore the decisive primary physical ecosystem engineer in the Za{\"i} system, initiating the restoration process. The mass of soil bioturbated in the course of foraging increased strongly from the degraded, barren towards the most rehabilitated reforested site. Combining all 36 experimental plots per Za{\"i} stage, Odontotermes bioturbated 31.8 tons of soil per hectare and month dry season in the degraded area, and 32.4 tons ha-1 mon-1 in the millet fields; both genera moved 138.9 tons ha-1 mon-1 in the young and 215.5 tons ha-1 mon-1 in the old Za{\"i} forest. Few comparable figures were found in the literature. In northern Burkina Faso, both genera constructed 20 tons of sheetings ha-1 mon-1 after mulching with a straw-wood mixture (Mando \& Miedema 1997), and in Senegal, around 10 tons ha-1 mon-1 were moved in heavily foraged plots (Rouland et al. 2003). Within a site, soil turn-over and the number of foraging holes created was always highest in hay, followed by compost, then by wood and in the end control. The fungus-growers' foraging-activity was leading to an enormous increase in surface pore space - after one month of induced foraging activity in hay-plots, the median number of foraging-holes increased from 142 m-2 in the degraded site up to 921 m-2 in the old Za{\"i} forest. The creation of subterranean galleries and macropores significantly increased the water infiltration rate by a mean factor 2-4. Laboratory analyses revealed that sheeting-soil differed strongly from the respective control soil as well as between the seasons, the food-type covered, and the two genera. Odontotermes-sheetings differed in more parameters than Macrotermes-sheetings, and dry season sheetings differed in more parameters (and more strongly) than rainy season sheetings. In the present study, soil organic matter, carbon and nitrogen contents were significantly increased in all dry season sheetings; in the rainy season mainly in those built on compost. Texture analysis pointed out that both genera used topsoil and soil from deeper horizons in varying mixture ratios, thereby supporting findings of Jouquet et al. (2006). To summarize, the present thesis contributes to a better understanding of the functional response traits of termites and ants to changing environmental parameters resulting from increasing human impact. The RAP-protocol represents an easy-to-learn and very effective method to representatively characterize, compare and monitor the taxonomic and functional diversity of termites and ants. The experiment has provided conclusive evidence of the importance of the consideration of fungus-growing termites (particularly Odontotermes and Macrotermes species) when aiming to restore infertile, degraded and crusted soils and to maintain a sustainable agricultural production in the Sahel-Sudanese zone of West Africa.},
  subject      = {Termiten},
  language  = {en}
}
@phdthesis{Andronic2014,
  author    = {Andronic, Joseph},
  title     = {Volumenregulatorische Transportwege von anorganischen und organischen Osmolyten in S{\"a}ugetierzellen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-103255},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Die Aufrechterhaltung des Zellvolumens unter variablen osmotischen Bedingungen stellt f{\"u}r nahezu alle tierischen Zellen eine essenzielle Aufgabe dar. Um regulatorische Volumenanpassungen vorzunehmen besitzen sie daher effektive Mechanismen, mit deren Hilfe der zellul{\"a}re Gehalt an organischen und anorganischen Osmolyten erh{\"o}ht (= regulatorische Volumenzunahme; RVI) oder gesenkt (= regulatorische Volumenabnahme; RVD) werden kann. Trotz langj{\"a}hriger Forschung auf diesem Gebiet konnten die hieran beteiligten Transportwege f{\"u}r Osmolyte bisher nur unvollst{\"a}ndig aufgekl{\"a}rt werden. Insbesondere bei T-Lymphozyten sind wichtige Zellfunktionen wie die Proliferation, Migration und die T-Zell-Aktivierung eng mit volumenregulatorischen Mechanismen verbunden. Bei all diesen Prozessen sind u. a. unterschiedliche Kaliumkan{\"a}le beteiligt, die insbesondere f{\"u}r die pharmakologische Manipulation von Immunsystemprozessen von wissenschaftlichem Interesse sind. Bisherige Modelle der hypotonen Volumenregulation von T-Lymphozyten ber{\"u}cksichtigen lediglich den spannungsabh{\"a}ngigen KV1.3 sowie den Ca2+-aktivierten IKCa1-Kanal, die zur Klasse der 6TM/P-K+-Kan{\"a}le geh{\"o}ren. Im ersten Teil der vorliegenden Arbeit wurde eine potentielle Rolle von k{\"u}rzlich entdeckten Zwei-Poren Dom{\"a}nen Kaliumkan{\"a}len (K2P) am RVD von murinen und humanen prim{\"a}ren CD4+-T-Lymphozyten untersucht. In einem kombinierten genetischen und pharmakologischen Ansatz mittels knockout-Tiermodellen und dem Einsatz kanalspezifischer Inhibitoren konnte mithilfe zellvolumetrischer Analysen gezeigt werden, dass die K2P-Vertreter TASK1, TASK2, TASK3 und TRESK maßgeblich am schwellungsaktivierten Efflux von K+ beteiligt sind. Beurteilt an den Ergebnissen dieser Untersuchung sind der spannungsabh{\"a}ngige TASK2- und der Ca2+-aktivierte TRESK-Kanal f{\"u}r die hypotone Volumenregulation in T-Zellen deutlich bedeutender als TASK1 und TASK3. Der Beitrag der Kan{\"a}le TASK2 und TRESK am RVD-Prozess war {\"u}ber dies vergleichbar mit dessen des bisher bekannten KV1.3-Kanals. In dieser Arbeit wurde damit erstmals eine Beteiligung der K2P-Kan{\"a}le am RVD muriner und humaner CD4+-Lymphozyten identifiziert. Aufgrund der engen Verbindung zwischen T-Zell-Funktion und der Volumenregulation k{\"o}nnen Zwei-Poren Dom{\"a}nen K+-Kan{\"a}le damit in den engeren Kreis potentieller immunmodulierende Angriffspunkte aufgefasst werden. Im zweiten und umfangreicheren Teil dieser Arbeit wurden dar{\"u}ber hinaus die schwellungsaktivierten Transportwege f{\"u}r organische Osmolyte (small organic osmolytes; SOOs) untersucht. SOOs stellen chemisch inerte Verbindungen dar, zu denen vor allem Polyole (Sorbitol, myo-Inositol), Methylamine (Betain, α-Glycerophosphocholin) sowie Aminos{\"a}uren (α- bzw. β-Alanin und Prolin) und deren Derivate (Taurin) z{\"a}hlen. Da SOOs weder die zellul{\"a}re Struktur noch die Funktion von Makromolek{\"u}len beeintr{\"a}chtigen, sind sie wichtige Instrumente der Volumenregulation, die sich in hohen Konzentrationen im Zytosol nahezu aller Zellen wiederfinden. Werden tierische Zellen mit hypotonen Bedingungen konfrontiert, dann ist bei nahezu allen Zellen die Freisetzung organischer Osmolyte zu beobachten, wodurch die zellul{\"a}re Osmolarit{\"a}t unabh{\"a}ngig von Elektrolyten angepasst werden kann. Trotz der wichtigen Funktion der SOOs in der Osmoregulation tierischer Zellen konnte die molekulare Identit{\"a}t beteiligter Effluxwege (Kan{\"a}le bzw. Transporter) bisher nicht aufgekl{\"a}rt werden. Ungeachtet der molekularen Identit{\"a}t der SOO-Effluxwege war es aus zahlreichen biotechnologischen Anwendungen zu Beginn dieser Arbeit bekannt, dass die schwellungsaktivierten Transportwege f{\"u}r organische Osmolyte eine gr{\"o}ßenselektive Permeabilit{\"a}t f{\"u}r eine Reihe monomerer Zucker und verwandter Verbindungen aufweisen. Um diese Gr{\"o}ßenselektivit{\"a}t n{\"a}her zu charakterisieren, wurde im ersten Schritt die schwellungsaktivierte Membranpermeabilit{\"a}t f{\"u}r eine Reihe strukturell homogener Polyethylenglykole unterschiedlicher Polymerl{\"a}nge (PEG200-1500; hydrodynamische Radien zwischen ~0,5-1,5 nm) unter iso- und hypotonen Bedingungen in Jurkat-Lymphozyten untersucht. Unter milden hypotonen Bedingungen (200 mOsm) war die Plasmamembran der untersuchten Lymphozyten f{\"u}r PEG300-1500 undurchl{\"a}ssig, was aus der F{\"a}higkeit der Zellen zur hypotonen Volumenregulation geschlossen werden konnte. Dar{\"u}ber hinaus wurde RVD in stark hypotonen L{\"o}sungen (100 mOsm) mit PEG600-1500 beobachtet, w{\"a}hrend PEG300-400 unter vergleichbaren osmotischen Bedingungen die Volumenregulation der Zellen inhibierten. Dieses Ergebnis deutet darauf hin, dass starkes hypotones Zellschwellen der Lymphozyten zur Permeabilisierung der Plasmamembran f{\"u}r PEG300-400, nicht jedoch f{\"u}r PEG600-1500, f{\"u}hrt. Anhand der hydrodynamischen Radien Rh der verwendeten PEGs konnte ein cutoff-Radius von ~0,74 nm f{\"u}r schwellungsaktivierte Transportwege organischer Osmolyte bestimmt werden. Da diese schwellungsaktivierten Transportwege vielf{\"a}ltig f{\"u}r Zellbeladungstechniken verwendet werden, k{\"o}nnte dieses Ergebnis f{\"u}r zahlreiche biotechnologische und biomedizinische Anwendungen von Interesse sein. Im zweiten Schritt wurde der Versuch unternommen, potentielle Transportwege f{\"u}r organische Osmolyte im RVD-Prozess molekular zu identifizieren. Da es grundlegend ungekl{\"a}rt war, wie viele unterschiedliche Transporter bzw. Kan{\"a}le am Efflux der zahlreichen organischen Osmolyte beteiligt sind, erfolgte zun{\"a}chst die vergleichende Analyse des schwellungsaktivierten Membrantransports strukturell verschiedener SOOs einschließlich der Aminosulfons{\"a}ure Taurin und des Polyols myo-Inositol. Hierbei wurde erstmals gezeigt, dass die schwellungsaktivierten Transportwege f{\"u}r Taurin und myo-Inositol deutlich unterschiedliche Aktivit{\"a}tsprofile aufweisen. W{\"a}hrend der Taurintransport bereits unter milden hypotonen Bedingungen, d.h. nach einer geringen Absenkung der Osmolalit{\"a}t von 300 auf ~230 mOsm, aktiviert wurde, erfolgte die Aktivierung der Membranpermeabilit{\"a}t f{\"u}r myo-Inositol bei einer viel niedrigeren Osmolalit{\"a}t von ~150 mOsm. Dar{\"u}ber hinaus wiesen die beiden Transportwege unter vergleichbarem hypotonen Stress von 100 mOsm deutlich unterschiedliche Aktivit{\"a}tsdauern auf (Transport von Taurin ~95 min und myo-Inositol ~40 min). Somit deuteten diese Ergebnisse erstmals auf substrat-spezifische Transportwege f{\"u}r SOOs hin, die voneinander stark abweichende osmotische Aktivierungsprofile besitzen. Als aussichtsreiche Kandidaten f{\"u}r diese Transportwege wurden zwei Mitglieder der Gruppe der Solute Carrier (SLC) untersucht, die klare {\"U}bereinstimmungen mit den gesuchten Transportern f{\"u}r SOOs aufweisen. Daher wurde im Weiteren eine RVD-Beteiligung dieser Transportergruppe mit einer Kombination aus molekularbiologischer und konventioneller bzw. hochaufgel{\"o}ster mikroskopischen Techniken {\"u}berpr{\"u}ft. Die semiqantitativen RT-PCR-Ergebnisse dieser Arbeit zeigen dabei, dass die Gentranskription der potentiellen SOO-Transporter SLC5A3 und SLC6A6 in den untersuchten Zelllinien Jurkat, HEK wie auch HepG2-Zellen durch hypotone Bedingungen deutlich verst{\"a}rkt wird. Hierbei nimmt der zellul{\"a}re mRNA-Gehalt der Gene SLC5A3 zwischen 20-60\% und SLC6A6 um 30-100\% innerhalb von 10-20 min zu, was auf eine potentielle RVD-Beteiligung von SLC-Transportern hindeutet. Ausgehend von diesem Ergebnis wurde daraufhin die zellul{\"a}re Lokalisation des SLC5A3-Transporters unter isotonen und hypotonen Bedingungen mikroskopisch untersucht. Wie anhand der konfokalen lasermikroskopischen Untersuchung zu erkennen ist, findet unter hypotoner Stimulation eine zellul{\"a}re Umverteilung des mit EGFP fluoreszenzmarkierten Proteins SLC5A3 statt. Innerhalb von 10 min wird der Transporter dabei von intrazellul{\"a}ren Regionen in Richtung Plasmamembran verlagert. Dar{\"u}ber hinaus konnte mit Hilfe der hochaufl{\"o}senden Mikroskopie-Technik dSTORM gezeigt werden, dass der Transporter SLC5A3 unter hypotoner Stimulation verst{\"a}rkt mit der Plasmamembran assoziiert vorliegt. Diese verst{\"a}rkte Membranassoziation des SLC5A3-Proteins deutet damit auf einen schwellungsinduzierten exozytotischen Einbau des Transporters hin. Die Ergebnisse dieser Arbeit zeigen damit erstmals, dass SLC-Transporter wie SLC5A3, SLC6A6 und vermutlich andere Vertreter der SLC-Superfamilie potentiell am Mechanismus der hypotonen Volumenregulation beteiligt sind. Da SLC-Transporter als wichtige Transportsysteme f{\"u}r Therapeutika angesehen werden und die Mechanismen der Volumenregulation bereits in zahlreichen biotechnologischen Anwendungen implementiert sind, k{\"o}nnte der hier aufgedeckte Zusammenhang einen Erkenntnisgewinn f{\"u}r zahlreiche biomedizinische Forschungsgebiete darstellen.},
  subject      = {S{\"a}ugetiere},
  language  = {de}
}
@phdthesis{Fackler2014,
  author    = {Fackler, Marc},
  title     = {Biochemical characterization of GAS2L3, a target gene of the DREAM complex},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-103394},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {GAS2L3 was identified recently as a target gene of the DREAM complex (Reichert et al., 2010; Wolter et al., 2012). It was shown that GAS2L3 is expressed in a cell cycle specific manner and that depletion of the protein leads to defects in cytokinesis and genomic instability (Wolter et al., 2012). Major aim of this thesis was, to further characterize the biochemical properties and physiological function of GAS2L3. By in vitro co-sedimentation and bundling assays, GAS2L3 was identified as a cytoskeleton associated protein which bundles, binds and crosslinks F-actin and MTs. GST pulldown assays and co-immunoprecipitation experiments revealed that GAS2L3 interacts in vitro and in vivo with the chromosomal passenger complex (CPC), a very important regulator of mitosis and cytokinesis, and that the interaction is mediated by the GAR domain of GAS2L3 and the C-terminal part of Borealin and the N-terminal part of Survivin. Kinase assays showed that GAS2L3 is not a substrate of the CPC but is strongly phosphorylated by CDK1 in vitro. Depletion of GAS2L3 by shRNA influenced protein stability and activity of the CPC. However pharmacological studies showed that the decreased CPC activity is not responsible for the observed cytokinesis defects upon GAS2L3 depletion. Immunofluorescence experiments revealed that GAS2L3 is localized to the constriction zone by the CPC in a GAR dependent manner and that the GAR domain is important for proper protein function. New interacting proteins of GAS2L3 were identified by stable isotope labelling by amino acids in cell culture (SILAC) in combination with tandem affinity purification and subsequent mass spectrometrical analysis. Co-immunoprecipitation experiments further confirmed the obtained mass spectrometrical data. To address the physiological function of GAS2L3 in vivo, a conditional and a non-conditional knockout mouse strain was established. The non-conditional mouse strain showed a highly increased mortality rate before weaning age probably due to heart failure. The physiological function of GAS2L3 in vivo as well as the exact reason for the observed heart phenotype is not known at the moment.},
  subject      = {Zellzyklus},
  language  = {en}
}
@phdthesis{Hofstetter2014,
  author    = {Hofstetter, Christine},
  title     = {Inhibition of H3K27me-Specific Demethylase Activity During Murine ES cell Differentiation Induces DNA Damage Response},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107023},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Stem cells are defined by their capacity to self-renew and their potential to differentiate into multiple cell lineages. Pluripotent embryonic stem (ES) cells can renew indefinitely while keeping the potential to differentiate into any of the three germ layers (ectoderm, endoderm or mesoderm). For decades, ES cells are in the focus of research because of these unique features. When ES cells differentiate they form spheroid aggregates termed "embryoid bodies" (EBs). These EBs mimic post- implantation embryonic development and therefore facilitate the understanding of developmented mechanisms. During ES cell differentiation, de-repression or repression of genes accompanies the changes in chromatin structure. In ES cells, several mechanisms are involved in the regulation of the chromatin architecture, including post-translational modifications of histones. Post-translational histone methylation marks became one of the best- investigated epigenetic modifications, and they are essential for maintaining pluripotency. Until the first histone demethylase KDM1A was discovered in 2004 histone modifications were considered to be irreversible. Since then, a great number of histone demethylases have been identified. Their activity is linked to gene regulation as well as to stem cell self-renewal and differentiation. KDM6A and KDM6B are H3K27me3/2-specific histone demethylases, which are known to play a central role in the regulation of posterior development by regulating HOX gene expression. So far less is known about the molecular function of KDM6A or KDM6B in undifferentiated and differentiating ES cells. In order to completely abrogate KDM6A and KDM6B demethylase activity in undifferentiated and differentiating ES cells, a specific inhibitor (GSK-J4) was employed. Treatment with GSK-J4 had no effect on the viability or proliferation on ES cells. However, in the presence of GSK-J4 ES cell differentiation was completely abrogated with cells arrested in G1-phase and an increased rate of apoptosis. Global transcriptome analyses in early-differentiating ES cells revealed that only a limited set of genes were differentially regulated in response to GSK-J4 treatment with more genes up- regulated than down-regulated. Many of the up-regulated genes are linked to DNA damage response (DDR). In agreement with this, DNA damage was found in EBs incubated with GSK-J4. A co-localization of H3K27me3 or KDM6B with γH2AX foci, marking DNA breaks, could be excluded. However, differentiating Eed knockout (KO) ES cells, which are devoid of the H3K27me3 mark, showed an attenuated GSK-J4- induced DDR. Finally, hematopoietic differentiation in the presence of GSK-J4 resulted in a reduced colony-forming potential. This leads to the conclusion that differentiation in the presence of GSK-J4 is also restricted to hematopoietic differentiation. In conclusion, my results show that the enzymatic activity of KDM6A and KDM6B is not essential for maintaining the pluripotent state of ES cells. In contrast, the enzymatic activity of both proteins is indispensable for ES cell and hematopoietic differentiation. Additionally KDM6A and KDM6B enzymatic inhibition in differentiating ES cells leads to increased DNA damage with an activated DDR. Therefore, KDM6A and KDM6B are associated with DNA damage and in DDR in differentiating ES cells.},
  subject      = {Embryonale Stammzelle},
  language  = {en}
}
@phdthesis{Wende2014,
  author    = {Wende, Beate},
  title     = {Diversity of saproxylic beetles and host tree specialisation in differently managed forests across Germany},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107049},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Chapter I The gradual turnover of dead organic material into mineral nutrients is a key ecological function, linking decomposition and primary production, the essential parts of the nutrient-energy cycle. However, disturbances in terms of species or resource losses might impair the equilibrium between production and decomposition. Humanity has converted large proportions of natural landscapes and intensified land-use activity for food production. Globally, only very few areas are totally unaffected by human activity today. To ensure the maintenance of both essential ecosystem services, knowledge about the interplay of biodiversity and ecosystem functioning as well as effects of intensified management on both is crucial. The vast majority of terrestrial biomass production as well as decomposition take place in forest ecosystems. Though forestry has a long sustainable history in Europe, its intensification during the last century has caused severe impacts on forest features and, consequently, on the associated biota, especially deadwood dependent organisms. Among these, saproxylic beetles are the most diverse group in terms of species numbers and functional diversity, but also most endangered due to habitat loss. These features classify them as ideal research organisms to study effects of intensified forestry on ecosystem services. The BELONGDEAD project located in Germany aimed to investigate deadwood decay and functional consequences of diversity changes in the associated fauna on the decomposition process from the initialisation of deadwood decay to complete degradation. As part of the BeLongDead project, this dissertation focussed on saproxylic beetle species, thereby evaluating (1) regionally effects of tree species identity of fresh deadwood and (2) forest management of varying intensities on the diversity, abundance and community composition of saproxylic beetles (chapter II); (3) the specialisation degree of different trophic guilds of saproxylic beetles, and thus the stability and robustness of their interaction networks against disturbances (chapter III); (4) the impact of environmental features of local to regional spatial scales on species richness of saproxylic beetles differing in their habitat niche in terms of deadwood decay stages (chapter IV). Chapter II The vast majority of European forest ecosystems have been anthropogenically affected, leaving less than 1\% of the about 1 milliard hectare as natural forests. A long history of forestry and especially the technological progress during the last century have caused massive habitat fragmentation as well as substantial loss of essential resources in European forest ecosystems. Due to this, the substrate-dependent group of saproxylic beetles has experienced severe species losses. Thus, investigations concerning saproxylic diversity and deadwood volume were badly needed. However, the importance of different deadwood in terms of tree species identity for the colonization by saproxylic beetles under different local and regional management regimes is poorly understood. Therefore, we studied possible regional differences in colonization patterns of saproxylic beetle species in a total of 688 fresh deadwood logs of 13 tree species in 9 sites of managed conifer and beech forests, and unmanaged beech forests, respectively. We found that tree species identity was an important driver in determining saproxylic species composition and abundance within fresh deadwood. However, saproxylic species showed different colonization patterns of deadwood items of the same tree species among the study regions. Regionally consistent, conifer forests were most diverse. We attribute the latter result to the historically adaption of saproxylic beetle species to semi-open forests, which conditions are actually best reflected by conifer forests. To preserve a diverse local species pool of early successional saproxylic beetles, we suggest an equal high degree of deadwood diversity in a tree species context in due consideration of regional differences. Chapter III The extinction risk of a particular species corresponds with its species-specific requirements on resources and habitat conditions, in other words with the width of the species` ecological niche. Species with a narrow ecological niche are defined as specialists. Members of this group experience higher extinction risk by resource limitation than generalists, which are able to utilize a variety of resources. For the classification of species as specialists or generalists, thus evaluating possible extinction risks, ecologists use the concept of interaction networks. This method has often been applied for mutualistic or antagonistic plant-animal interactions, but information for networks of detritivores is scarce. Therefore, saproxylic beetle species sampled as described in chapter II were categorised according to their larval diet; additionally their interaction networks (N=108) with 13 dead host tree species were analysed. Specialisation degree was highest for wood-digesting beetles and decreased with increasing trophic level. Also the network indices evaluating robustness and generality indicated a higher susceptibility to species extinctions for xylophagous than for mycetophagous and predatory beetles. The specialisation of xylophagous species on specific tree species might be an adaption to tree species specific ingredients stored for defence against pathogens and pests. However, we conclude that the high specialisation degree of xylophages and thus their higher extinction risk by resource loss harbours certain dangers for ecosystem function and stability as species diversity is positively linked to both. Chapter IV Populations depend on individual emigration and immigration events to ensure genetic exchange. For successful migration it is of utmost importance that spatially separated populations are obtainable by specimen. Migratory success depends on the one hand on the species dispersal abilities and on the other on the availability of suitable habitats in the surrounding landscape in which the distinct host populations exist. However, consequences of intensive forest management correspond not only to severe reduction of local deadwood amount, but, among others, also a change in tree species composition and high levels of fragmentation in the surrounding forest area. Saproxylic beetle species differ in their dispersal behaviour according to the temporal availability of their preferred habitat. Generally, early successional saproxylic beetles are able to disperse over large distances, whereas beetles inhabiting advanced decayed wood often remain close to their larval habitat. Due to this, environmental factors might affect saproxylic beetle guilds differently. We classified the saproxylic beetles sampled as described in chapter II according to their calculated habitat niche as early, intermediate or late successional saproxylic beetles. For the different guilds the effects of 14 environmental factors on different spatial scales (stand factors at 0.1 km radius, landscape composition at 2 km radius, and regionally differing abiotic factors in 400 km to 700 km distance) were investigated. Consistently for all guilds, species richness decreased with fragmentation at local and landscape scale, and increased in warmer climate. However, we found contradictory results between the guilds to some extent. We relate this to guild specific habitat requirements of the saproxylic beetles. Therefore, for the development of appropriate conservation practices guild-specific requirements saproxylic beetles have to be considered not only locally but on larger spatial scales. Chapter V In conclusion, this dissertation identified main drivers of early successional saproxylic beetle species richness on various spatial scales. Our results emphasize the importance to develop management schemes meeting species-specific and guild-specific habitat requirements of the saproxylic beetle fauna at relevant spatial and temporal scales. Therefore, short-term actions suggested for sustainable forest management should be the focus on a diverse tree species composition consisting of indigenous tree species with respect to regional differences. Moreover, senescent trees, fallen and standing deadwood should remain in the forests, and some tree individuals should be allowed to grow old. Long-term actions should involve the reduction of forest fragmentation and the connection of spatial widely separated forest fragments. Furthermore, to fully understand the effects of forest management long-term research should be conducted to compare habitat requirements of intermediate and late successional beetles with the results presented in this dissertation.},
  subject      = {Saproxylophage},
  language  = {en}
}
@phdthesis{Schwarze2014,
  author    = {Schwarze, Simone},
  title     = {Untersuchung von Faltungs- und Funktionsdynamik isolierter Proteindom{\"a}nen mittels Fluoreszenzl{\"o}schung},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107080},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Proteine bestehen aus einer spezifischen Sequenz verschiedener Aminos{\"a}uren, die ihre charakteristische Funktion bestimmt. Die große Variabilit{\"a}t an Aminos{\"a}uresequenzen erm{\"o}glichte die Evolution einer nahezu unbegrenzten Anzahl an Proteinen. Meistens nehmen diese Schl{\"u}sselpositionen ein, von robusten Baustoffen bis hin zu molekularen Maschinen. Daher kann eine Fehlfunktion gravierende Auswirkungen auf das Leben haben, z.B. Krankheiten wie Alzheimer oder Epilepsi. Um die Funktionen und Fehlfunktionen zu verstehen, ist eine umfassende Kenntnis der Proteinfaltung, der Protein-Protein Assoziation, sowie den Dynamiken innerhalb von Proteinen erforderlich. Diese Vorg{\"a}nge wurden in dieser Arbeit an drei isolierten Proteindom{\"a}nen durch die Anwendung der Fluoreszenzl{\"o}schmechanismen der H-Dimerbildung und des photoinduzierten Elektronentransfers untersucht. Der entfaltete Zustand der Bindungsdom{\"a}ne BBL, das Teil des 2-oxo-acid Dehydrogenasekomplexes ist, wurde unter physiologischen Bedingungen mit Zirkulardichroismus (CD) und einer Kombination aus photoinduziertem Elektronentransfer und Fluoreszenzkorrelationsspektroskopie analysiert. Beide Methoden zeigten {\"u}bereinstimmend anhand von 20 in BBL einzeln eingef{\"u}gten konservativen Punktmutationen, dass Seitenketteninteraktionen keine Auswirkungen auf die Sekund{\"a}rstruktur des denaturierten Zustandes, den Ausgangspunkt der Faltung, haben. Mit Hilfe der Dekonvolation der CD-Spektren wurde zudem gezeigt, dass die Reststruktur im denaturierten Zustand der helikalen Proteindom{\"a}ne von β-Str{\"a}ngen und β-Kehren dominiert wird, die eine entscheidende Funktion bei der Faltung in den nativen Zustand haben k{\"o}nnten. Die N-terminale Dom{\"a}ne (NTD), der f{\"u}r die Materialforschung hochinteressanten Spinnen-seidenfaser, ist f{\"u}r die Polymerisation des Spinnenseidenfadens auf den pH-Wechsel von pH 7 auf pH 6 hin verantwortlich. Dieser f{\"u}r die Proteinfunktion wichtige Prozess wurde durch die Einbringung eines extrinsischen Fluoreszenzschalters, basierend auf der H-Dimerbildung, mit der Stopped-Flow-Technik untersucht. Es wurde gezeigt, dass die NTDs 104 mit einer Rate von 3 x 10^8 M-1 s-1 assoziieren und somit nahezu das Geschwindigkeitslimit der Protein-Protein Assoziation erreicht wird. Zwei geladenen Seitenketten, der D39 und D40, kommt eine entscheidende Funktion in dem Prozess zu, da eine Mutation dieser die Assoziation verhindert. Des Weiteren wurde gezeigt, dass sich die NTD auf eine Erh{\"o}hung der Ionenst{\"a}rke entgegengesetzt zu anderen Proteinen verh{\"a}lt: die Dissoziation wird beschleunigt, die Assoziation nicht beeinflusst. Gleiches Verhalten wurde auf den einzelnen Austausch der {\"u}brigen protonierbaren Aminos{\"a}ureseitenketten hin beobachtet, ausgenommen die Mutation der E119, welche die Dissoziation verlangsamt. Daher scheint der makromolekulare Dipol, der auf Grund der Ladungsverteilung in der NTD entsteht, die Assoziation maßgeblich zu beeinflussen. Glutamatrezeptoren sind an der schnellen synaptischen Signalweiterleitung im Nervensys-tem von Vertebraten beteiligt. Die Konformationen der Ligandenbindungsdom{\"a}ne (LBD) haben dabei entscheidende Auswirkungen auf die Funktion des Gesamtrezeptors. Diese wurden mit einer Kombination aus photoinduziertem Elektronentransfer und Fluoreszenzkorrelationsspektroskopie untersucht. Mit dieser Methode wurde ein dynamisches Bild der gebundenen sowie ungebundenen Form der AMPA-spezifischen Glutamatrezeptor 2-LBD gezeigt. Es wurde zudem gezeigt, dass sich die Dynamiken in Abh{\"a}ngigkeit der Bindung von den Agonisten Glutamat und AMPA, dem partiellen Agonisten Kainate oder Cyclothiazid (CTZ), welches eine Dimerisierung der LBDs bewirkt, unterschiedlich ver{\"a}ndern. Dies k{\"o}nnte eine Auswirkung auf die Funktion der Rezeptoren haben. Die Anwendung der Fluoreszenzl{\"o}schmechanismen der H-Dimerbildung und des photoinduzierten Elektronentransfers in dieser Arbeit hat gezeigt, dass diese die M{\"o}glichkeit bieten, unterschiedlichste Fragestellungen zu beantworten und so Einblicke in dynamische Funktionsweisen von Proteinen er{\"o}ffnen. Kombiniert mit etablierten Fluoreszenzmethoden ist es so m{\"o}glich quantitativ Kinetiken auf unterschiedlichen Zeitskalen zu untersuchen.},
  subject      = {Protein-Protein-Wechselwirkung},
  language  = {de}
}
@phdthesis{Schulze2014,
  author    = {Schulze, Katja},
  title     = {Automatisierte Klassifizierung und Viabilit{\"a}tsanalyse von Phytoplankton},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107174},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Zentrales Ziel dieser Arbeit war es, Methoden der Mikroskopie, Bildverarbeitung und Bilderkennung f{\"u}r die Charakterisierungen verschiedener Phyotplankter zu nutzen, um deren Analyse zu verbessern und zu vereinfachen. Der erste Schwerpunkt der Arbeit lag auf der Analyse von Phytoplanktongemeinschaften, die im Rahmen der {\"U}berpr{\"u}fung der S{\"u}ßwasserqualit{\"a}t als Marker dienen. Die konventionelle Analyse ist dabei sehr aufwendig, da diese noch immer vollst{\"a}ndig von Hand durchgef{\"u}hrt wird und hierf{\"u}r speziell ausgebildetes Personal eingesetzt werden muss. Ziel war es, ein System zur automatischen Erkennung aufzubauen, um die Analyse vereinfachen zu k{\"o}nnen. Mit Hilfe von automatischer Mikroskopie war es m{\"o}glich Plankter unterschiedlicher Ausdehnung durch die Integration mehrerer Sch{\"a}rfeebenen besser in einem Bild aufzunehmen. Weiterhin wurden verschiedene Fluoreszenzeigenschaften in die Analyse integriert. Mit einem f{\"u}r ImageJ erstellten Plugin k{\"o}nnen Organismen vom Hintergrund der Aufnahmen abgetrennt und eine Vielzahl von Merkmalen berechnet werden. {\"U}ber das Training von neuralen Netzen wird die Unterscheidung von verschieden Gruppen von Planktontaxa m{\"o}glich. Zudem k{\"o}nnen weitere Taxa einfach in die Analyse integriert und die Erkennung erweitert werden. Die erste Analyse von Mischproben, bestehend aus 10 verschiedenen Taxa, zeigte dabei eine durchschnittliche Erkennungsrate von 94.7\% und eine durchschnittliche Falsch-Positiv Rate von 5.5\%. Im Vergleich mit bestehenden Systemen konnte die Erkennungsrate verbessert und die Falsch Positiv Rate deutlich gesenkt werde. Bei einer Erweiterung des Datensatzes auf 22 Taxa wurde darauf geachtet, Arten zu verwenden, die verschiedene Stadien in ihrem Wachstum durchlaufen oder h{\"o}here {\"A}hnlichkeiten zu den bereits vorhandenen Arten aufweisen, um evtl. Schwachstellen des Systemes erkennen zu k{\"o}nnen. Hier ergab sich eine gute Erkennungsrate (86.8\%), bei der der Ausschluss von nicht-planktonischen Partikeln (11.9\%) weiterhin verbessert war. Der Vergleich mit weiteren Klassifikationsverfahren zeigte, dass neuronale Netze anderen Verfahren bei dieser Problemstellung {\"u}berlegen sind. {\"A}hnlich gute Klassifikationsraten konnten durch Support Vektor Maschinen erzielt werden. Allerdings waren diese bei der Unterscheidung von unbekannten Partikeln dem neuralen Netz deutlich unterlegen. Der zweite Abschnitt stellt die Entwicklung einer einfachen Methode zur Viabilit{\"a}tsanalyse von Cyanobakterien, bei der keine weitere Behandlung der Proben notwendig ist, dar. Dabei wird die rote Chlorophyll - Autofluoreszenz als Marker f{\"u}r lebende Zellen und eine gr{\"u}ne unspezifische Fluoreszenz als Marker f{\"u}r tote Zellen genutzt. Der Assay wurde mit dem Modellorganismus Synechocystis sp. PCC 6803 etabliert und validiert. Die Auswahl eines geeigeneten Filtersets erm{\"o}glicht es beide Signale gleichzeitig anzuregen und zu beobachten und somit direkt zwischen lebendenden und toten Zellen zu unterscheiden. Die Ergebnisse zur Etablierung des Assays konnten durch Ausplattieren, Chlorophyllbestimmung und Bestimmung des Absorbtionsspektrums best{\"a}tigt werden. Durch den Einsatz von automatisierter Mikroskopie und einem neu erstellten ImageJ Plugin wurde eine sehr genaue und schnelle Analyse der Proben m{\"o}glich. Der Einsatz beim Monitoring einer mutagenisierten Kultur zur Erh{\"o}hung der Temperaturtoleranz erm{\"o}glichte genaue und zeitnahe Einblicke in den Zustand der Kultur. Weitere Ergebnisse weisen darauf hin, dass die Kombination mit Absorptionsspektren es erm{\"o}glichen k{\"o}nnen bessere Einblicke in die Vitalit{\"a}t der Kultur zu erhalten.},
  subject      = {Bilderkennnung},
  language  = {de}
}
@article{MeucheBrusaLinsenmairetal.2013,
  author    = {Meuche, Ivonne and Brusa, Oscar and Linsenmair, K. Eduard and Keller, Alexander and Pr{\"o}hl, Heike},
  title     = {Only distance matters - non-choosy females in a poison frog population},
  series = {Frontiers in Zoology},
  volume    = {10},
  journal   = {Frontiers in Zoology},
  number    = {29},
  issn      = {1742-9994},
  doi       = {10.1186/1742-9994-10-29},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122617},
  year      = {2013},
  abstract  = {Background: Females have often been shown to exhibit preferences for certain male traits. However, little is known about behavioural rules females use when searching for mates in their natural habitat. We investigated mate sampling tactics and related costs in the territorial strawberry poison frog (Oophaga pumilio) possessing a lek-like mating system, where both sequential and simultaneous sampling might occur. We continuously monitored the sampling pattern and behaviour of females during the complete period between two successive matings. Results: We found no evidence that females compared males by visiting them. Instead females mated with the closest calling male irrespective of his acoustic and physical traits, and territory size. Playback experiments in the natural home ranges of receptive females revealed that tested females preferred the nearest speaker and did not discriminate between low and high call rates or dominant frequencies. Conclusions: Our results suggest that females of O. pumilio prefer the closest calling male in the studied population. We hypothesize that the sampling tactic in this population is affected by 1) a strongly female biased sex ratio and 2) a low variance in traits of available males due to strong male-male competition, preventing low quality males from defending a territory and mating.},
  language  = {en}
}
@article{ChenGerber2014,
  author    = {Chen, Yi-chun and Gerber, Bertram},
  title     = {Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila},
  series = {The Journal of Experimental Biology},
  volume    = {217},
  journal   = {The Journal of Experimental Biology},
  number    = {12},
  doi       = {10.1242/jeb.100966},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121625},
  pages     = {2071-7},
  year      = {2014},
  abstract  = {Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour-reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances.},
  language  = {en}
}
@phdthesis{Scholz2017,
  author    = {Scholz, Nicole},
  title     = {Genetic analyses of sensory and motoneuron physiology in Drosophila melanogaster},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123249},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {During my PhD I studied two principal biological aspects employing Drosophila melanogaster. Therefore, this study is divided into Part I and II. Part I: Bruchpilot and Complexin interact to regulate synaptic vesicle tethering to the active zone cytomatrix At the presynaptic active zone (AZ) synaptic vesicles (SVs) are often physically linked to an electron-dense cytomatrix - a process referred to as "SV tethering". This process serves to concentrate SVs in close proximity to their release sites before contacting the SNARE complex for subsequent fusion (Hallermann and Silver, 2013). In Drosophila, the AZ protein Bruchpilot (BRP) is part of the proteinous cytomatrix at which SVs accumulate (Kittel et al., 2006b; Wagh et al., 2006; Fouquet et al., 2009). Intriguingly, truncation of only 1\% of the C-terminal region of BRP results in a severe defect in SV tethering to this AZ scaffold (hence named brpnude; Hallermann et al., 2010b). Consistent with these findings, cell-specific overexpression of a C-terminal BRP fragment, named mBRPC-tip (corresponds to 1\% absent in brpnude; m = mobile) phenocopied the brpnude mutant in behavioral and functional experiments. These data indicate that mBRPC-tip suffices to saturate putative SV binding sites, which induced a functional tethering deficit at motoneuronal AZs. However, the molecular identity of the BRP complement to tether SVs to the presynaptic AZ scaffold remains unknown. Moreover, within larval motoneurons membrane-attached C-terminal portions of BRP were sufficient to tether SVs to sites outside of the AZ. Based on this finding a genetic screen was designed to identify BRP interactors in vivo. This screen identified Complexin (CPX), which is known to inhibit spontaneous SV fusion and to enhance stimulus evoked SV release (Huntwork and Littleton, 2007; Cho et al., 2010; Martin et al., 2011). However, so far CPX has not been associated with a function upstream of priming/docking and release of SVs. This work provides morphological and functional evidence, which suggests that CPX promotes recruitment of SVs to the AZ and thereby curtails synaptic short-term depression. Together, the presented findings indicate a functional interaction between BRP and CPX at Drosophila AZs. Part II: The Adhesion-GPCR Latrophilin/CIRL shapes mechanosensation The calcium independent receptor of α-latrotoxin (CIRL), also named Latrophilin, represents a prototypic Adhesion class G-protein coupled-receptor (aGPCR). Initially, Latrophilin was identified based on its capacity to bind the α-component of latrotoxin (α-LTX; Davletov et al., 1996; Krasnoperov et al., 1996), which triggers massive exocytotic activity from neurons of the peripheral nervous system (Scheer et al., 1984; Umbach et al., 1998; Orlova et al., 2000). As a result Latrophilin is considered to play a role in synaptic transmission. Later on, Latrophilins have been associated with other biological processes including tissue polarity (Langenhan et al., 2009), fertility (Pr{\"o}mel et al., 2012) and synaptogenesis (Silva et al., 2011). However, thus far its subcellular localization and the identity of endogenous ligands, two aspects crucial for the comprehension of Latrophilin's in vivo function, remain enigmatic. Drosophila contains only one latrophilin homolog, named dCirl, whose function has not been investigated thus far. This study demonstrates abundant dCirl expression throughout the nervous system of Drosophila larvae. dCirlKO animals are viable and display no defects in development and neuronal differentiation. However, dCirl appears to influence the dimension of the postsynaptic sub-synaptic reticulum (SSR), which was accompanied by an increase in the postsynaptic Discs-large abundance (DLG). In contrast, morphological and functional properties of presynaptic motoneurons were not compromised by the removal of dCirl. Instead, dCirl is required for the perception of mechanical challenges (acoustic-, tactile- and proprioceptive stimuli) through specialized mechanosensory devices, chordotonal organs (Eberl, 1999). The data indicate that dCirl modulates the sensitivity of chordotonal neurons towards mechanical stimulation and thereby adjusts their input-output relation. Genetic interaction analyses suggest that adaption of the molecular mechanotransduction machinery by dCirl may underlie this process. Together, these results uncover an unexpected function of Latrophilin/dCIRL in mechanosensation and imply general modulatory roles of aGPCR in mechanoception.},
  subject      = {Drosophila},
  language  = {en}
}
@phdthesis{Grosz2015,
  author    = {Grosz, Magdalena Urszula},
  title     = {Identification of phagosomal escape relevant factors in Staphylococcus aureus infection},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121981},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Staphylococcus aureus is a facultative Gram-positive human pathogen which can cause different severe infections. Staphylococci are phagocytosed by professional and non-professional phagocytes; they are strongly cytotoxic against eukaryotic cells and have been proposed to play a role in immune evasion by spreading within migrating phagocytes. This study investigated the post invasive events upon S. aureus infection. Strains which are able to escape the phagosome were identified and the responsible toxins were determined. Thereby innovative insights into host pathogen interaction were obtained. A novel class of small amphipathic peptides with strong surfactant-like properties, the phenol soluble modulins, particularly PSMα as well as the leukocidin LukAB, are involved in phagosomal escape of the clinical S. aureus strains LAC, MW2 and 6850 in non-professional and professional phagocytes. Whereas, PSMβ, δ-toxin, α-toxin, β-toxin or phosphatidyl inositol-dependent phospholipase C did not affect phagosomal escape. By blocking the bacterial DNA-dependent RNA polymerase with rifampicin phagosomal escape is determined to start approximately 2.5 hours post infection. Phagosomal escape further was required for intracellular replication of S. aureus. Strains which are not able to escape cannot replicate in the acidic vacuole, whereas, the host cytoplasm offers a rich milieu for bacterial replication. Additionally, phagosomal escape, with intracellular bacterial replication induces the subsequent host cell death. This could be confirmed by an infection assay including S. aureus knockout mutants in psmα or lukAB which were significantly less cytotoxic, compared with those infected with escape-positive wild type strains. Further, this study showed that phagosomal escape is not only mediated by bacterial toxins. Since, the phagocyte-specific cognate receptors for both escape relevant toxins, FPR2 (PSMα receptor) and CD11b (LukAB receptor) are produced in epithelial and endothelial cells only after infection with S. aureus in a calcium dependent fashion. The knockdown of both receptors using siRNA prevents S. aureus to escape the phagosome. Furthermore, blocking intracellular calcium release with the inositol trisphosphate receptor (IP3R) inhibitor 2-APB prohibits upregulation of fpr2 and cd11b and subsequently phagosomal escape of S. aureus. To conclude, the current study clarifies that phagosomal escape and host cell death are interplay of both, bacterial toxins and host cell factors. Staphylococcus aureus ist ein fakultativ Gram-positives Humanpathogen, dass verschiedene schwerwiegende Infektionen verursachen kann. Staphylokokken werden von professionellen und nicht-professionellen Phagozyten (Fresszellen) zu gleich aufgenommen. Desweitern sind sie stark zytotoxisch f{\"u}r eukaryotische Zellen. Außerdem wird vermutet, dass sie sich mittels migrierender Phagozyten dem angeborenen Immunsystem entziehen k{\"o}nnen. In dieser Studie werden die post-invasiven Ereignisse w{\"a}hrend einer Staphylokokken Infektion untersucht. Im Detail wurden St{\"a}mme identifiziert die aus den Phagosomen entkommen k{\"o}nnen und die daf{\"u}r verantwortlichen Toxine. Im Zuge dessen wurden neue Erkenntnisse der Interaktion zwischen Bakterien und Wirtszellen gewonnen. Eine neue Klasse von kleinen amphiphatischen Peptiden mit starken grenzfl{\"a}chenaktiven Eigenschaften (Surfactant), die sogenannten Phenol soluble modulins (PSMs) im Besonderen PSMα sowie das Leukozidin LukAB, sind am phagosomalen Ausbruch der klinisch relevanten S. aureus St{\"a}mmen LAC, MW2 und 6850 in nicht professionellen und professionellen Phagozyten involviert. Hingegen, sind PSMβ, δ-toxin, α-toxin, β-toxin oder Phosphatidylinositol abh{\"a}ngige Phospholipase C nicht am phagosomalen Ausbruch beteiligt. Durch die Hemmung der bakteriellen DNA-abh{\"a}ngigen RNA Polymerase mit Rifampicin wurde der Zeitpunkt f{\"u}r den Ausbruch auf etwa 2,5 Stunden nach der Infektion eingegrenzt. Der phagosomale Ausbruch ist weiterhin f{\"u}r die intrazellul{\"a}re Replikation von S. aureus notwendig. W{\"a}hrend St{\"a}mme, die nicht ausbrechen k{\"o}nnen in der anges{\"a}uerten Vakuole nicht replizieren k{\"o}nnen, bietet das Zytoplasma ein reichhaltiges Milieu f{\"u}r die Vermehrung. Zudem wird der Pathogen induzierte Zelltod erst nach dem phagosomalen Ausbruch und mit anschließender Vermehrung erm{\"o}glicht. Nachgewiesen wurde dies mittels psmα und lukAB defizienten Mutanten welche signifikant weniger zytotoxisch waren als der Wildtyp Stamm. Diese Studie zeigt dar{\"u}ber hinaus, dass der phagosomale Ausbruch nicht nur durch bakterielle Toxine vermittelt wird. Sondern, dass die Phagozyten-spezifischen Rezeptoren f{\"u}r beide relevanten Toxine, FPR2 (PSMα Rezeptor) und CD11b (LukAB Rezeptor), in Epithel- und Endothelzellen nach Infektion mit S. aureus calciumabh{\"a}ngig produziert werden und f{\"u}r den Ausbruch notwendig sind. Der knockdown beider Rezeptoren mittels siRNA verhindert den Ausbruch. Wird der intrazellul{\"a}re Calciumstrom mittels des Inositoltrisphosphat Rezeptor (IP3R) Inhibitor 2-APB blockiert k{\"o}nnen die Gene fpr2 und cd11b nicht hochreguliert werden und der Ausbruch wird ebenfalls verhindert. Folglich zeigt diese Studie, dass der phagosomale Ausbruch und Pathogen induzierte Zelltod sowohl durch bakterielle Toxine als auch Wirtsfaktoren vermittelt wird.},
  subject      = {Phagosom},
  language  = {en}
}
@article{MenzelBluethgenTolaschetal.2013,
  author    = {Menzel, Florian and Bl{\"u}thgen, Nico and Tolasch, Till and Conrad, J{\"u}rgen and Beifuss, Uwe and Beuerle, Till and Schmitt, Thomas},
  title     = {Crematoenones - a novel substance class exhibited by ants functions as appeasement signal},
  series = {Frontiers in Zoology},
  volume    = {10},
  journal   = {Frontiers in Zoology},
  number    = {32},
  issn      = {1742-9994},
  doi       = {10.1186/1742-9994-10-32},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122595},
  year      = {2013},
  abstract  = {Background: Parasitic, commensalistic, and mutualistic guests in social insect colonies often circumvent their hosts' nestmate recognition system to be accepted. These tolerance strategies include chemical mimicry and chemical insignificance. While tolerance strategies have been studied intensively in social parasites, little is known about these mechanisms in non-parasitic interactions. Here, we describe a strategy used in a parabiotic association, i.e. two mutualistic ant species that regularly share a common nest although they have overlapping food niches. One of them, Crematogaster modiglianii, produces an array of cuticular compounds which represent a substance class undescribed in nature so far. They occur in high abundances, which suggests an important function in the ant's association with its partner Camponotus rufifemur. Results: We elucidated the structure of one of the main compounds from cuticular extracts using gas chromatography, mass spectrometry, chemical derivatizations and nuclear magnetic resonance spectroscopy (NMR). The compound consists of two fused six-membered rings with two alkyl groups, one of which carries a keto functionality. To our knowledge, this is the first report on the identification of this substance class in nature. We suggest naming the compound crematoenone. In behavioural assays, crematoenones reduced interspecific aggression. Camponotus showed less aggression to allospecific cuticular hydrocarbons when combined with crematoenones. Thus, they function as appeasement substances. However, although the crematoenone composition was highly colony-specific, interspecific recognition was mediated by cuticular hydrocarbons, and not by crematoenones. Conclusions: Crematenones enable Crematogaster to evade Camponotus aggression, and thus reduce potential costs from competition with Camponotus. Hence, they seem to be a key factor in the parabiosis, and help Crematogaster to gain a net benefit from the association and thus maintain a mutualistic association over evolutionary time. To our knowledge, putative appeasement substances have been reported only once so far, and never between non-parasitic species. Since most organisms associated with social insects need to overcome their nestmate recognition system, we hypothesize that appeasement substances might play an important role in the evolution and maintenance of other mutualistic associations as well, by allowing organisms to reduce costs from antagonistic behaviour of other species.},
  language  = {en}
}
@article{FraunholzSinha2012,
  author    = {Fraunholz, Martin and Sinha, Bhanu},
  title     = {Intracellular staphylococcus aureus: Live-in and let die},
  series = {Frontiers in Cellular and Infection Microbiology},
  volume    = {2},
  journal   = {Frontiers in Cellular and Infection Microbiology},
  number    = {43},
  doi       = {10.3389/fcimb.2012.00043},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123374},
  year      = {2012},
  abstract  = {Staphylococcus aureus uses a plethora of virulence factors to accommodate a diversity of niches in its human host. Aside from the classical manifestations of S. aureus-induced diseases, the pathogen also invades and survives within mammalian host cells. The survival strategies of the pathogen are as diverse as strains or host cell types used. S. aureus is able to replicate in the phagosome or freely in the cytoplasm of its host cells. It escapes the phagosome of professional and non-professional phagocytes, subverts autophagy, induces cell death mechanisms such as apoptosis and pyronecrosis, and even can induce anti-apoptotic programs in phagocytes. The focus of this review is to present a guide to recent research outlining the variety of intracellular fates of S. aureus.},
  language  = {en}
}
@article{DietzHasseFerrarisetal.2013,
  author    = {Dietz, Mariana S. and Hasse, Daniel and Ferraris, Davide M. and G{\"o}hler, Antonia and Niemann, Hartmut H. and Heilemann, Mike},
  title     = {Single-molecule photobleaching reveals increased MET receptor dimerization upon ligand binding in intact cells},
  series = {BMC Biophysics},
  volume    = {6},
  journal   = {BMC Biophysics},
  number    = {6},
  issn      = {2046-1682},
  doi       = {10.1186/2046-1682-6-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121835},
  year      = {2013},
  abstract  = {Background: The human receptor tyrosine kinase MET and its ligand hepatocyte growth factor/scatter factor are essential during embryonic development and play an important role during cancer metastasis and tissue regeneration. In addition, it was found that MET is also relevant for infectious diseases and is the target of different bacteria, amongst them Listeria monocytogenes that induces bacterial uptake through the surface protein internalin B. Binding of ligand to the MET receptor is proposed to lead to receptor dimerization. However, it is also discussed whether preformed MET dimers exist on the cell membrane. Results: To address these issues we used single-molecule fluorescence microscopy techniques. Our photobleaching experiments show that MET exists in dimers on the membrane of cells in the absence of ligand and that the proportion of MET dimers increases significantly upon ligand binding. Conclusions: Our results indicate that partially preformed MET dimers may play a role in ligand binding or MET signaling. The addition of the bacterial ligand internalin B leads to an increase of MET dimers which is in agreement with the model of ligand-induced dimerization of receptor tyrosine kinases.},
  language  = {en}
}
@article{RybalkaWolfAndersenetal.2013,
  author    = {Rybalka, Nataliya and Wolf, Matthias and Andersen, Robert and Friedl, Thomas},
  title     = {Congruence of chloroplast- and nuclear-encoded DNA sequence variations used to assess species boundaries in the soil microalga Heterococcus (Stramenopiles, Xanthophyceae)},
  series = {BMC Evolutionary Biology},
  volume    = {13},
  journal   = {BMC Evolutionary Biology},
  number    = {39},
  issn      = {1471-2148},
  doi       = {10.1186/1471-2148-13-39},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121848},
  year      = {2013},
  abstract  = {Background: Heterococcus is a microalgal genus of Xanthophyceae (Stramenopiles) that is common and widespread in soils, especially from cold regions. Species are characterized by extensively branched filaments produced when grown on agarized culture medium. Despite the large number of species described exclusively using light microscopic morphology, the assessment of species diversity is hampered by extensive morphological plasticity. Results: Two independent types of molecular data, the chloroplast-encoded psbA/rbcL spacer complemented by rbcL gene and the internal transcribed spacer 2 of the nuclear rDNA cistron (ITS2), congruently recovered a robust phylogenetic structure. With ITS2 considerable sequence and secondary structure divergence existed among the eight species, but a combined sequence and secondary structure phylogenetic analysis confined to helix II of ITS2 corroborated relationships as inferred from the rbcL gene phylogeny. Intra-genomic divergence of ITS2 sequences was revealed in many strains. The 'monophyletic species concept', appropriate for microalgae without known sexual reproduction, revealed eight different species. Species boundaries established using the molecular-based monophyletic species concept were more conservative than the traditional morphological species concept. Within a species, almost identical chloroplast marker sequences (genotypes) were repeatedly recovered from strains of different origins. At least two species had widespread geographical distributions; however, within a given species, genotypes recovered from Antarctic strains were distinct from those in temperate habitats. Furthermore, the sequence diversity may correspond to adaptation to different types of habitats or climates. Conclusions: We established a method and a reference data base for the unambiguous identification of species of the common soil microalgal genus Heterococcus which uses DNA sequence variation in markers from plastid and nuclear genomes. The molecular data were more reliable and more conservative than morphological data.},
  language  = {en}
}
@phdthesis{Larsen2015,
  author    = {Larsen, Mirjam},
  title     = {Zur genetischen Heterogenit{\"a}t der Muskeldystrophien: alternative genetische Ursachen der Myotonen Dystrophie und FSHD},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123431},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Die klinische Symptomatik verschiedener erblicher Muskelerkrankungen verl{\"a}uft oft erstaunlich {\"a}hnlich mit Muskelschw{\"a}che und -schwund als den hervorstechenden Alltagsproblemen. Dem gegen{\"u}ber sind die genetischen Grundlagen sehr vielf{\"a}ltig mit > 250 bisher identifizierten Genen (musclegenetable.org). Auch innerhalb eines definierten Krankheitsbildes werden verschiedene genetische Ursachen nebeneinander gefunden, was durch die Verkn{\"u}pfung in einem gemeinsamen Pathomechanismus begr{\"u}ndet sein kann. Die vorliegende Arbeit besch{\"a}ftigt sich mit verschiedenen Aspekten dieser genetischen Heterogenit{\"a}t am Beispiel der beiden h{\"a}ufigen Muskelerkrankungen Myotone Dystrophie (DM) und Facioscapulohumerale Muskeldystrophie (FSHD), bei denen alternative genetische Ursachen, sowie ankn{\"u}pfende Fragestellungen untersucht wurden. Das erste Projekt dieser Arbeit besch{\"a}ftigt sich mit Fragestellungen, welche die DM betreffen. Die DM Typ 1 und Typ 2 (DM1 und DM2) bilden zusammen die h{\"a}ufigste Muskelerkrankung im Erwachsenenalter. Sie ist durch die gemeinsamen Symptome Myotonie, Muskelschw{\"a}che und Katarakt sowie die Beteiligung weiterer Organsysteme gekennzeichnet, was sie zu einer multisystemischen Erkrankung macht. Die genetische Ursache liegt f{\"u}r beide Formen in einer Repeatexpansion eines Mikrosatelliten in der untranslatierten Region zweier Gene (DMPK in DM1, CNBP in DM2). Dem gemeinsamen Pathomechanismus liegt eine toxische Funktionsgewinn-Mutation des expandierten RNA-Transkripts zugrunde. Die beiden bekannten Formen der DM sind ph{\"a}notypisch h{\"a}ufig nicht unterscheidbar, weshalb in vielen F{\"a}llen beide Erkrankungen molekulargenetisch untersucht werden m{\"u}ssen. Dabei ist die Diagnostik der DM durch die Notwendigkeit des Nachweises von sehr großen Repeatexpansionen recht aufw{\"a}ndig und die Bestimmung der Repeatl{\"a}nge im Fall der DM2 nur eingeschr{\"a}nkt m{\"o}glich. Im Rahmen dieser Arbeit wurde ein Test zum Nachweis der Repeatexpansionen auf der Basis der Methode des Molecular Combing entwickelt, welche den gleichzeitigen Nachweis der beiden Loci von DM1 und DM2 erlaubt und zus{\"a}tzlich eine direkte Messung der Repeatl{\"a}nge erm{\"o}glicht. Das Molecular Combing ist eine fluoreszenz-mikroskopische Einzelmolek{\"u}l-Analysemethode, durch die es erstmals m{\"o}glich wurde, die vermutete somatische Instabilit{\"a}t bei DM2 darzustellen. Das zweite DM-Teilprojekt besch{\"a}ftigt sich mit der Identifikation m{\"o}glicher alternativer genetischer Ursachen f{\"u}r die Erkrankung. Dies wurde anhand einer Kohorte von 138 DM1- und DM2-negativen Indexpatienten mit dem typischen DM-Ph{\"a}notyp untersucht. Ausgehend von dem gemeinsamen Pathomechanismus wurden die prim{\"a}ren Krankheitsgene DMPK und CNBP, sowie CELF1 und MBNL1, welche wichtige Rollen auf sekund{\"a}rer Ebene des Pathomechanismus spielen, mittels Next Generation Sequencing untersucht. Dabei wurde eine auff{\"a}llige Variante in DMPK gefunden, keine Varianten in CNBP oder CELF1 und drei Varianten in MBNL1, was auf MBNL1 als Kandidatengen einer alternativen Ursache f{\"u}r DM hinweist. MBNL1 ist ein gewebespezifischer Spleißregulator, welcher einen Wechsel von einem fetalen zu einem adulten Spleißmuster im Muskel steuert. Die Pathogenit{\"a}t einer der Varianten wurde in einem RNA-Spleißassay mit MBNL1-Targetgenen untersucht. Dabei konnten keine spezifischen Spleiß-Effekte festgestellt werden, aber eine Verminderung des Expressionsniveaus im Sinne einer Haploinsuffizienz. Die 3D-Modellierung dieser Variante deutet auf {\"A}nderungen der Oberfl{\"a}chenladungen in MBNL1 hin. Der Nachweis der Pathogenit{\"a}t der Varianten und somit die Urs{\"a}chlichkeit von MBNL1-Mutationen f{\"u}r DM konnte hiermit nicht abschließend gekl{\"a}rt werden. Die gefundenen Ergebnisse regen jedoch hoffentlich zu nachfolgenden Studien an. Das zweite Projekt dieser Arbeit besch{\"a}ftigt sich mit Fragestellungen um die FSHD. Diese bildet die dritth{\"a}ufigste Muskelerkrankung, charakterisiert durch eine oft asymmetrische Schw{\"a}che der Muskulatur von Gesicht, Schulterg{\"u}rtel und Oberarmen. Genetisch ist die FSHD Typ 1 (FSHD1) mit einer Kontraktion des Makrosatelliten D4Z4 verkn{\"u}pft, was eine Relaxation der Chromatinstruktur der Region mit sich bringt und damit die ektopische Expression des apoptotisch wirkenden Proteins DUX4 erm{\"o}glicht. Die pathogene Auspr{\"a}gung dieser Funktionsgewinn-Mutation findet dabei nur in Verbindung mit einem FSHD-permissiven Haplotyp statt. Auf der Grundlage des gleichen Pathomechanismus wurde eine zweite Form der FSHD (FSHD2) vorgestellt, bei der die Chromatinrelaxation unabh{\"a}ngig von der L{\"a}nge von D4Z4 durch einen Defekt in dem an der DNA-Methylierung beteiligten Gen SMCHD1 assoziiert sein soll. Die Vererbung von FSHD2 verl{\"a}uft digenisch mit Mutationen in SMCHD1 und dem FSHD-permissiven Haplotyp auf zwei unabh{\"a}ngigen Loci. Im Rahmen dieser Arbeit wurde eine Kohorte von 55 FSHD1-negativen Patienten mit dem typischen FSHD-Ph{\"a}notyp untersucht. Dabei wurden der Haplotyp, die Methylierung von D4Z4 sowie das SMCHD1-Gen analysiert. Es konnten neun Patienten mit einem Defekt in SMCHD1 identifiziert werden. In einer zweiten Kohorte von 45 FSHD1-positiven Patienten wurde untersucht, ob SMCHD1-Mutationen auch in Kombination mit einer Kontraktion von D4Z4 vorkommen. Dieser Fall von FSHD1+2 konnte f{\"u}r drei Patienten gezeigt werden, welche außerdem einen auff{\"a}llig schweren Ph{\"a}notyp zeigten. SMCHD1 kann also als Modifier-Gen f{\"u}r die Schwere der Erkrankung bei FSHD1 angesehen werden. Damit wurden insgesamt zw{\"o}lf SMCHD1-Mutationstr{\"a}ger identifiziert, davon sind zehn der Varianten noch nicht beschrieben worden. F{\"u}r alle erkrankten Mutationstr{\"a}ger konnte eine Methylierung von D4Z4 ≤ 20 \% ermittelt werden, was als diagnostisches Kriterium verwendet werden kann. Mit einem Anteil von 16,3 \% Mutationstr{\"a}ger in der FSHD1-negetiven Kohorte bildet FSHD2 einen bedeutenden Anteil an dem Krankheitsbild der FSHD, weshalb die entwickelten Analysen in die Routinediagnostik eingegliedert wurden. Das zweite Teilprojekt der FSHD besch{\"a}ftigt sich mit der Funktion des SMCHD1-Gens bei der X-Inaktivierung (XI). Es ist bekannt, dass SMCHD1 bei weiblichen M{\"a}usen an der Aufrechterhaltung der XI mitwirkt. Die Untersuchung der XI bei FSHD2-Frauen ergab eine extreme Verschiebung der erwarteten XI von 50:50 auf 0:100 oder 100:0 bei sechs von 13 Patientinnen. Die {\"u}brigen sieben zeigten eine XI im Normalbereich von > 20:80 oder < 80:20. Der Befund der einseitigen Verschiebung k{\"o}nnte auf einen negativen Selektionsdruck gegen{\"u}ber Zellen mit unvollst{\"a}ndiger XI hindeuten. Es w{\"a}re interessant zu untersuchen, ob sich der gleiche Effekt auch in einer gr{\"o}ßeren Kohorte wiederfindet und ob er sich mit der Art der Mutation korrelieren l{\"a}sst.},
  subject      = {Myotonische Dystrophie},
  language  = {de}
}
@phdthesis{Tsoneva2017,
  author    = {Tsoneva, Desislava},
  title     = {Humanized mouse model: a system to study the interactions of human immune system with vaccinia virus-infected human tumors in mice},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118983},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Ein vielversprechender neuer Ansatz zur Behandlung von Krebs beim Menschen ist die Verwendung von onkolytischen Viren, die einen Tumor-spezifischen Tropismus aufweisen. Einer der Top-Kandidaten in diesem Bereich ist das onkolytische Vaccinia Virus (VACV), das bereits vielversprechende Ergebnisse in Tierversuchen und in klinischen Studien gezeigt hat. Aber die von den in vivo in tierischen Modellen erhaltenen Resultate k{\"o}nnten ungenaue Informationen wegen der anatomischen und physiologischen Unterschiede zwischen den Spezies liefern. Andererseits sind Studien in Menschen aufgrund ethischer Erw{\"a}gungen und potenzieller Toxizit{\"a}t nur limitiert m{\"o}glich. Die zahlreichen Einschr{\"a}nkungen und Risiken, die mit den Humanstudien verbunden sind, k{\"o}nnten mit der Verwendung eines humanisierten Mausmodells vermieden werden. Die LIVP-1.1.1, GLV-2b372, GLV-1h68, GLV-1h375, GLV-1h376 and GLV-1h377 VACV St{\"a}mmen wurden von der Genelux Corporation zur Verf{\"u}gung gestellt. GLV-2b372 wurde durch Einf{\"u}gen der TurboFP635 Expressionskassette in den J2R Genlocus des parentalen LIVP-1.1.1-Stammes konstruiert. GLV-1h375, -1h376 and -1h377 kodiert das Gen f{\"u}r den menschlichen CTLA4-blockierenden Einzelketten-Antik{\"o}rper (CTLA4 scAb). Befunde aus Replikations- and Zytotoxizit{\"a}tsstudien zeigten, dass alle sechs Viren Tumorzellen infizieren, sich in ihnen replizieren und sie in Zellkultur schließlich ebenso dosis- und zeitabh{\"a}ngig effizient abt{\"o}ten konnten. CTLA4 scAb und β-Glucuronidase (GusA) Expression sowie Virus Titer in GLV-1h376-infizierten A549-Zellen wurde anhand von ELISA-, β-Glucuronidase- and Standard Plaque-Assays bestimmt. Hierbei zeigte sich eine ausgezeichnete Korrelation mit Korrelationskoeffizienten R2>0.9806. Der durch das GLV-1h376 kodierte CTLA4 scAb wurde erfolgreich aus {\"U}berst{\"a}nden von infizierten CV-1-Zellen gereinigt. CTLA4 scAb hat eine hohe in-vitro-Affinit{\"a}t zu seinem menschlichen CTLA4-Zielmolek{\"u}l sowie abwesende Kreuzreaktivit{\"a}t gegen{\"u}ber murine CTLA4 gezeigt. CTLA4 scAb Funktionalit{\"a}t wurde in Jurkat-Zellen best{\"a}tigt. LIVP-1.1.1, GLV-2b372, GLV-1h68 und GLV-1h376 wurden auch in nicht-tumor{\"o}sen und/oder tumortragenden humanisierten M{\"a}usen getestet. Zun{\"a}chst wurde gezeigt, dass die Injektion von menschlichen CD34+ Stammzellen in die Leber von vorkonditionierten neugeborenen NSG M{\"a}usen zu einer erfolgreichen systemische Rekonstitution mit menschlichen Immunzellen gef{\"u}hrt hat. CD19+-B-Zellen, CD4+- und CD8+-CD3+-T-Zellen, NKp46+CD56- und NKp46+CD56+-NK-Zellen sowie CD33+-myeloischen Zellen wurden detektiert. Die Mehrheit der nachgewisenen humanen h{\"a}matopoetischen Zellen im M{\"a}useblut in den ersten Wochen nach der Humanisierung waren CD19+-B-Zellen, und nur ein kleiner Teil waren CD3+-T-Zellen. Mit der Zeit wurde eine signifikante Ver{\"a}nderung in CD19+/CD3+-Verh{\"a}ltnis beobachtet, die parallel zur Abnahme der B-Zellen und einem Anstieg der T-Zellen kam. Die Implantation von A549-Zellen unter die Haut dieser M{\"a}use f{\"u}hrte zu einem progressiven Tumorwachstum. Bildgebende Verfahren zur Detektion von Virus-vermittelter TurboFP635- und GFP-Expression, Standard Plaque Assays sowie immunohistochemische Analysen best{\"a}tigten die erfolgreiche Invasion der Viren in die subkutanen Tumoren. Die humane CD45+-Zellpopulation in Tumoren wurde haupts{\"a}chlich durch NKp46+CD56bright-NK-Zellen und einen hohen Anteil von aktivierten CD4+- und zytotoxische CD8+-T-Zellen dargestellt. Es wurden jedoch keine signifikanten Unterschiede zwischen den Kontroll- und LIVP-1.1.1-infizierten Tumoren beobachtet, was darauf hindeutete, dass die Rekrutierung von NK- und aktivierten T-Zellen, mehr Tumorgewebe-spezifisch als Virus-abh{\"a}ngig waren. Die GLV-1h376-vermittelten CTLA4 scAb-Expression in den infizierten Tumoren war ebenfalls nicht in der Lage, die Aktivierung von Tumor-infiltrierenden T-Zellen im Vergleich zur Kontrolle und GLV-1h68-behandelten M{\"a}usen, signifikant zu erh{\"o}hen. ELISA-, β-Glucuronidase- and Standard Plaque-Assays zeigten eine eindeutige Korrelation mit den Korrelationskoeffizienten R2>0,9454 zwischen CTLA4 scAb- und GusA-Konzentrationen und Virus Titer in Tumorproben von GLV-1h376-behandelten M{\"a}usen. T-Zellen, die aus der Milz dieser Tumor-tragenden M{\"a}use isoliert wurden, waren funktionell und konnten erfolgreich mit Beads aktiviert werden. Mehr CD25+ und IFN-ɣ+ T-Zellen wurden in der GLV-1h376-Gruppe gefunden, wahrscheinlich aufgrund der CTLA4-Blockade durch die Virus-vermittelte CTLA4 scAb-Expression in den M{\"a}usen. Außerdem wurde eine h{\"o}here Konzentration von IL-2 in dem Kultur{\"u}berstand von diesen Splenozyten im Vergleich zu Kontrollproben nachgewiesen. Im Gegensatz zu der Aktivierung mit Beads konnten T-Zellen von allen drei Maus-Gruppen nicht durch A549 Tumorzellen ex vivo aktiviert werden. Unser Mausmodell hat den besonderen Vorteil, dass sich Tumoren unter der Haut der humanisierten M{\"a}use entwickeln, was eine genaue {\"U}berwachung des Tumorwachstums und Auswertung der onkolytischen Virotherapie erm{\"o}glicht.},
  subject      = {Vaccinia virus},
  language  = {en}
}
@phdthesis{Gnamlin2015,
  author    = {Gnamlin, Prisca},
  title     = {Use of Tumor Vasculature for Successful Treatment of Carcinomas by Oncolytic Vaccinia Virus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119019},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Tumor-induced angiogenesis is of major interest for oncology research. Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor characterized so far. VEGF blockade was shown to be sufficient for angiogenesis inhibition and subsequent tumor regression in several preclinical tumor models. Bevacizumab was the first treatment targeting specifically tumor-induced angiogenesis through VEGF blockade to be approved by the Food and Drugs Administration (FDA) for cancer treatment. However, after very promising results in preclinical evaluations, VEGF blockade did not show the expected success in patients. Some tumors became resistant to VEGF blockade. Several factors have been accounted responsible, the over-expression of other angiogenic factors, the noxious influence of VEFG blockade on normal tissues, the selection of hypoxia resistant neoplastic cells, the recruitment of hematopoietic progenitor cells and finally the transient nature of angiogenesis inhibition by VEGF blockade. The development of blocking agents against other angiogenic factors like placental growth factor (PlGF) and Angiopoietin-2 (Ang-2) allows the development of an anti-angiogenesis strategy adapted to the profile of the tumor. Oncolytic virotherapy uses the natural propensity of viruses to colonize tumors to treat cancer. The recombinant vaccinia virus GLV-1h68 was shown to infect, colonize and lyse several tumor types. Its descendant GLV-1h108, expressing an anti-VEGF antibody, was proved in previous studies to inhibit efficiently tumor induced angiogenesis. Additional VACVs expressing single chain antibodies (scAb) antibodies against PlGF and Ang-2 alone or in combination with anti VEGF scAb were designed. In this study, VACV-mediated anti-angiogenesis treatments have been evaluated in several preclinical tumor models. The efficiency of PlGF blockade, alone or in combination with VEGF, mediated by VACV has been established and confirmed. PlGF inhibition alone or with VEGF reduced tumor burden 5- and 2-folds more efficiently than the control virus, respectively. Ang-2 blockade efficiency for cancer treatment gave controversial results when tested in different laboratories. Here we demonstrated that unlike VEGF, the success of Ang-2 blockade is not only correlated to the strength of the blockade. A particular balance between Ang-2, VEGF and Ang-1 needs to be induced by the treatment to see a regression of the tumor and an improved survival. We saw that Ang-2 inhibition delayed tumor growth up to 3-folds compared to the control virus. These same viruses induced statistically significant tumor growth delays. This study unveiled the need to establish an angiogenic profile of the tumor to be treated as well as the necessity to better understand the synergic effects of VEGF and Ang-2. In addition angiogenesis inhibition by VACV-mediated PlGF and Ang-2 blockade was able to reduce the number of metastases and migrating tumor cells (even more efficiently than VEGF blockade). VACV colonization of tumor cells, in vitro, was limited by VEGF, when the use of the anti-VEGF VACV GLV-1h108 drastically improved the colonization efficiency up to 2-fold, 72 hours post-infection. These in vitro data were confirmed by in vivo analysis of tumors. Fourteen days post-treatment, the anti-VEGF virus GLV-1h108 was colonizing 78.8\% of the tumors when GLV-1h68 colonization rate was 49.6\%. These data confirmed the synergistic effect of VEGF blockade and VACV replication for tumor regression. Three of the tumor cell lines used to assess VACV-mediated angiogenesis inhibition were found, in certain conditions, to mimic either endothelial cell or pericyte functions, and participate directly to the vascular structure. The expression by these tumor cells of e-selectin, p-selectin, ICAM-1 and VCAM-1, normally expressed on activated endothelial cells, corroborates our findings. These proteins play an important role in immune cell recruitment, and there amount vary in presence of VEGF, PlGF and Ang-2, confirming the involvement of angiogenic factors in the immuno-modulatory abilities of tumors. In this study VACV-mediated angiogenesis blockade proved its potential as a therapeutic agent able to treat different tumor types and prevent resistance observed during bevacizumab treatment by acting on different factors. First, the expression of several antibodies by VACV would prevent another angiogenic factor to take over VEGF and stimulate angiogenesis. Then, the ability of VACV to infect tumor cells would prevent them to form blood vessel-like structures to sustain tumor growth, and the localized delivery of the antibody would decrease the risk of adverse effects. Next, the blockade of angiogenic factors would improve VACV replication and decrease the immune-modulatory effect of tumors. Finally the fact that angiogenesis blockade lasts until total regression of the tumor would prevent the recovery of the tumor-associated vasculature and the relapse of patients.},
  subject      = {Vaccinia-Virus},
  language  = {en}
}
@phdthesis{Fischer2015,
  author    = {Fischer, Robin},
  title     = {Generating useful tools for future studies in the center of the circadian clock - defined knockout mutants for PERIOD and TIMELESS},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119141},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {To unravel the role of single genes underlying certain biological processes, scientists often use amorphic or hypomorphic alleles. In the past, such mutants were often created by chance. Enormous approaches with many animals and massive screening effort for striking phenotypes were necessary to find a needle in the haystack. Therefore at the beginning chemical mutagens or radiation were used to induce mutations in the genome. Later P-element insertions and inaccurate jump-outs enabled the advantage of potential larger deletions or inversions. The mutations were characterized and subsequently kept in smaller populations in the laboratories. Thus additional mutations with unknown background effects could accumulate. The precision of the knockout through homologous recombination and the additional advantage of being able to generate many useful rescue constructs that can be easily reintegrated into the target locus made us trying an ends-out targeting procedure of the two core clock genes period and timeless in Drosophila melanogaster. Instead of the endogenous region, a small fragment of approximately 100 base pairs remains including an attP-site that can be used as integration site for in vitro created rescue constructs. After a successful ends-out targeting procedure, the locus will be restored with e.g. flies expressing the endogenous gene under the native promoter at the original locus coupled to a fluorescence tag or expressing luciferase. We also linked this project to other research interests of our work group, like the epigenetic related ADAR-editing project of the Timeless protein, a promising newly discovered feature of time point specific timeless mRNA modification after transcription with yet unexplored consequences. The editing position within the Timeless protein is likewise interesting and not only noticed for the first time. This will render new insights into the otherwise not-satisfying investigation and quest for functional important sequences of the Timeless protein, which anyway shows less homology to other yet characterized proteins. Last but not least, we bothered with the question of the role of Shaggy on the circadian clock. The impact of an overexpression or downregulation of Shaggy on the pace of the clock is obvious and often described. The influence of Shaggy on Period and Timeless was also shown, but for the latter it is still controversially discussed. Some are talking of a Cryptochrome stabilization effect and rhythmic animals in constant light due to Shaggy overexpression, others show a decrease of Cryptochrome levels under these conditions. Also the constant light rhythmicity of the flies, as it was published, could not be repeated so far. We were able to expose the conditions behind the Cryptochrome stabilization and discuss possibilities for the phenomenon of rhythmicity under constant light due to Shaggy overexpression.},
  subject      = {Biologische Uhr},
  language  = {en}
}
@phdthesis{Kuger2015,
  author    = {Kuger, Sebastian},
  title     = {Radiosensibilisierung humaner Tumorzelllinien unterschiedlicher Entit{\"a}ten durch den dualen PI3K/mTOR-Inhibitor NVP-BEZ235 alleine oder in Kombination mit dem MEK-Inhibitor AZD6244: Einfluss des Behandlungsschemas und der Hypoxie},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126715},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Eine wichtige Standardtherapie in der modernen Behandlung von Krebserkrankungen ist die Strahlentherapie, in welcher Tumorzellen mittels ionisierender Strahlung gesch{\"a}digt und abget{\"o}tet werden. Dabei soll die Sch{\"a}digung des umgebenden Normalgewebes m{\"o}glichst gering gehalten und trotzdem eine maximale Sch{\"a}digung des Tumorgewebes erreicht werden. Deshalb sind neue Strategien zur Steigerung der Radiosensitivit{\"a}t des Tumorgewebes sehr wichtig, die es erlauben, bei gleicher Dosis eine verst{\"a}rkte Strahlenantwort im Tumorgewebe zu erreichen. Hier kommen zunehmend sog. Radiosensibilisatoren zum Einsatz, die unter anderem onkogene Signalwege in den Tumorzellen inhibieren. Der PI3K/Akt/mTOR Signalweg stellt hierbei einen wichtigen Ansatzpunkt dar, da er in vielen Tumorentit{\"a}ten dereguliert vorliegt und diese Signalkaskade bekanntermaßen einen Einfluss auf die zellul{\"a}re Strahlensensitivit{\"a}t hat. Obwohl es f{\"u}r diesen Signalweg schon eine Reihe von Inhibitoren gibt, f{\"u}r die bereits neben einer anti-proliferativen Wirkung auch ein radiosensibilisierender Effekt nachgewiesen wurde (z.B. Wortmannin und Rapamycin), machten eine geringe Spezifit{\"a}t, starke Nebenwirkungen und negative R{\"u}ckkopplungsmechanismen im Signalweg, die die Wirkung des Inhibitors kompensieren, die Entwicklung neuer Inhibitoren notwendig. Das Imidazoquinolinderivat NVP-BEZ235 inhibiert den PI3K/Akt/mTOR Signalweg an mehreren Stellen gleichzeitig, indem es kompetitiv zu ATP das katalytische Zentrum von PI3K und mTOR blockiert. F{\"u}r diesen kleinmolekularen, dualen Inhibitor gibt es bereits erste vielversprechende Forschungsergebnisse hinsichtlich einer radiosensibilisierenden Wirkung, allerdings sind die zugrunde liegenden molekularbiologischen Mechanismen noch nicht vollst{\"a}ndig gekl{\"a}rt. Deshalb war das Ziel der vorliegenden Dissertation, in drei Teilprojekten mehrere Aspekte der NVP-BEZ235-induzierten Radiosensibilisierung aufzukl{\"a}ren: a) Einfluss des Behandlungsschemas f{\"u}r NVP-BEZ235 in vier Glioblastomzelllinien mit unterschiedlichem PTEN und TP53 Mutationsstatus, b) Einfluss der Sauerstoffversorgung (Hypoxie, Normoxie, reoxygeniert nach Bestrahlung) auf die strahlensensibilisierende Wirkung von NVP-BEZ235 in zwei Mammakarzinomzelllinien, c) gleichzeitige Inhibierung des MAPK Signalwegs durch AZD6244 und der PI3K/Akt/mTOR Signalkaskade durch NVP-BEZ235 in zwei Zelllinien mit unter-schiedlichem Mutationsstatus aus verschiedenen Tumorentit{\"a}ten, um synergistische Effekte zu untersuchen. Um diese Fragestellungen zu beantworten, wurde im Rahmen - 142 - der Dissertation eine Auswahl an humanen Tumorzelllinien mit unterschiedlich deregulierten Signalwegen bearbeitet. Dabei wurde die Expression von Schl{\"u}sselproteinen der MAPK/Erk und der PI3K/Akt/mTOR Signalwege analysiert und mit zellbiologischen Daten verschiedener ph{\"a}notypischer Endpunkte nach Inhibitor Behandlung und Bestrahlung integriert (Proliferationsrate, klonogenes {\"U}berleben, Zellzyklusaberrationen, DNS-Sch{\"a}den und -Reparatur, Zelltod und Autophagie). Im Teilprojekt zum Behandlungsschema der NVP-BEZ235 Inhibierung und Bestrahlung konnte in vier Glioblastomzelllinien mit Behandlungsschema I (NVP-BEZ235 Behandlung 24 Stunden vor Bestrahlung) kein radiosensibilisierender Effekt hinsichtlich klonogenem {\"U}berleben nachgewiesen werden, wohingegen Behandlungsschema II (NVP-BEZ235 Behandlung 1 h vor und im Anschluss an die Bestrahlung) unabh{\"a}ngig vom Mutationsstatus in allen vier Zelllinien eine starke Radiosensibilisierung bewirkte. Auf molekularer Ebene war zwischen beiden Behandlungsschemata f{\"u}r das antiapoptotische Protein Akt ein großer Unterschied zu beobachten, welches bei Behandlung nach Schema I zum Zeitpunkt der Bestrahlung {\"u}beraktiviert, nach Behandlung mit Schema II hingegen inhibiert war. Weiterhin resultierte Behandlungsschema I in einem erh{\"o}hten Anteil der Zellen in der radioresistenteren G1-Phase des Zellzyklus zum Zeit-punkt der Bestrahlung. Behandlungsschema II f{\"u}hrte hingegen nach Bestrahlung zu einer verminderten Expression des Reparaturproteins Rad51 und damit zu verminderter DNS-Schadensreparatur und schließlich zu einem stabilen Arrest in der G2/M-Phase des Zellzyklus sowie zu verst{\"a}rkter Apoptose (erh{\"o}hte Spaltung von PARP, erh{\"o}hter Anteil hypodiploider Zellen). Somit zeigen diese Ergebnisse, dass unabh{\"a}ngig vom PTEN und TP53 Mutationsstatus eine Radiosensibilisierung nur durch das Behandlungsschema II erreicht werden konnte. Ferner deuten die Ergebnisse der Proteinexpression darauf hin, dass durch NVP-BEZ235 ein negativer R{\"u}ckkopplungsmechanismus ausgel{\"o}st wird, wodurch die PI3K/Akt/mTOR Signalkaskade 24h nach Zugabe des Inhibitors aktiviert und synergistische Effekte mit ionisierender Bestrahlung aufgehoben wurden. Im Teilprojekt zur Abh{\"a}ngigkeit der NVP-BEZ235 Inhibition vom Sauerstoffgehalt wurden in den beiden Brustkrebszelllinien MCF-7 (ER-positiv) und TN MDA-MB-231 (TP53 mutiert) normoxische, hypoxische und nach Bestrahlung reoxygenierte Kulturbedingungen im Hinblick auf die Koloniebildungsf{\"a}higkeit nach NVP-BEZ235 Behandlung und Bestrahlung untersucht. Die beobachtete Radiosensibilisierung war unter allen getesteten Bedingungen auf gleichem Niveau. In beiden Zelllinien bewirkte NVP-BEZ235 eine Inhibition des antiapoptotischen HIF-1α Proteins, eine stabile Inaktivierung des PI3K/Akt/mTOR Signalweges und eine Aktivierung der Autophagie. Nach Bestrahlung waren zudem erh{\"o}hte residuale DNS-Sch{\"a}den und ein stabiler Arrest in der G2/M-Phase des Zellzyklus unter allen Oxygenierungsbedingungen in beiden Zelllinien zu beobachten. Eine Apoptose Induktion (Spaltung von PARP, hypodiploide Zellen) trat nur in der TP53 wildtypischen MCF-7 Zelllinie nach NVP-BEZ235 Behandlung auf. Somit konnte in beiden Zelllinien in allen pathophysiologisch relevanten Oxygenierungszust{\"a}nden eine sauerstoffunabh{\"a}ngige Radiosensibilisierung durch NVP-BEZ235 gezeigt werden. Der bisher nicht erforschte Aspekt zur synergistischen Wirkung des MEK Inhibitors AZD6244 und des dualen PI3K/Akt/mTOR Inhibitors NVP-BEZ235 nach Bestrahlung wurde an der Glioblastomzelllinie SNB19 und der Lungenkarzinomzelllinie A549 anhand der Koloniebildungsf{\"a}higkeit der behandelten Zellen untersucht. Eine Behandlung mit dem MEK Inhibitor bewirkte lediglich eine moderate Radiosensibilisierung, wohin-gegen der duale PI3K/Akt/mTOR Inhibitor beide Zelllinien in st{\"a}rkerem Maße sensibilisierte. Eine Kombination beider Inhibitoren resultierte bei keiner Zelllinie in einer Verst{\"a}rkung der durch NVP-BEZ235 induzierten Radiosensibilisierung. Eine m{\"o}gliche Erkl{\"a}rung f{\"u}r die fehlende Synergie im Bezug auf die Radiosensibilisierung k{\"o}nnen die gegens{\"a}tzlichen Effekte der beiden Inhibitoren auf den Zellzyklus sein. Auf Proteinebene f{\"u}hrte eine simultane Behandlung mit beiden Substanzen zur Inhibition beider Signalwege. Dar{\"u}ber hinaus war in SNB19 Zellen eine verst{\"a}rkte Dephosphorylierung von Rb und ein erh{\"o}hter Anteil an G1-Phase Zellen bei kombinierter Gabe der Inhibitoren zu beobachten. Im Rahmen dieser Arbeit konnte somit die radiosensibilisierende Wirkung von NVP-BEZ235 in Abh{\"a}ngigkeit vom Behandlungsschema gezeigt werden. Ferner wurde nachgewiesen, dass die Radiosensibilisierung unabh{\"a}ngig von der Sauerstoffversorgung sowie von den PTEN und TP53 Mutationsstatus der Tumorzellen ist. Die kombinierte Inhibition der MAPK und PI3K/Akt/mTOR Signalwege resultierte zwar in einem verst{\"a}rkten zytostatischen, aber nicht in einem verst{\"a}rkten radiosensibilisierenden Effekt. Da allerdings eine große Anzahl verschiedener Inhibitoren der MAPK/Erk und der PI3K/Akt/mTOR Signalkaskade verf{\"u}gbar sind, sollte die kombinatorische Inhibition dieser Signalwege systematisch weiter verfolgt werden. Die vorliegende Arbeit liefert auch weitere grundlegende Erkenntnisse zu den molekularen Mechanismen der Radiosensibilisierung durch NVP-BEZ235, die auch auf Verkn{\"u}pfungen und Wechselwirkungen mit anderen als den bisher bekannten Proteinen hindeuten, die f{\"u}r jeden Inhibitor aufgekl{\"a}rt werden m{\"u}ssen, um eine effektive radiosensibilisierende Wirkung vorher-sagen zu k{\"o}nnen.},
  subject      = {Strahlensensibilisator},
  language  = {de}
}