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Formation of the Clypeolabral Region During Embryonic Head Development of the Red Flour Beetle Tribolium castaneum

dc.contributor.advisorBucher, Gregor Prof. Dr.de
dc.contributor.authorKittelmann, Sebastiande
dc.date.accessioned2013-01-14T15:06:32Zde
dc.date.available2013-01-30T23:50:28Zde
dc.date.issued2012-07-26de
dc.identifier.urihttp://hdl.handle.net/11858/00-1735-0000-000D-EF6C-Dde
dc.identifier.urihttp://dx.doi.org/10.53846/goediss-1446
dc.description.abstractInsekten sind segmentierte Organismen, allerdings ist umstritten, wie viele Segmente zur Bildung des Kopfes beitragen. Die vorderste Kopfregion entwickelt sich anders als der segmentierte Teil des Körpers und wird als nicht-segmental betrachtet. Während der Embryogenese kann diese nicht-segmentale Region in einen lateralen neurogenen und einen medianen weitgehend nicht-neuralen Abschnitt eingeteilt werden. Aufgrund derde
dc.format.mimetypeapplication/pdfde
dc.language.isoengde
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/de
dc.titleFormation of the Clypeolabral Region During Embryonic Head Development of the Red Flour Beetle Tribolium castaneumde
dc.typedoctoralThesisde
dc.title.translatedDie Entstehung der clypeolabralen Region während der embryonalen Kopfentwicklung des rotbraunen Reismehlkäfers Tribolium castaneumde
dc.contributor.refereeBucher, Gregor Prof. Dr.de
dc.date.examination2012-06-14de
dc.subject.dnb570 Biowissenschaften, Biologiede
dc.subject.gokWK 000de
dc.description.abstractengInsects are segmented organisms but the number of segments contributing to the head is disputed. The most anterior head region is patterned differently from the rest of the body and, therefore, is considered to be non-segmental. During embryogenesis, the non-segmental region can be subdivided into an outer neurogenic region and an inner triangular part which is mostly free of neurogenic precursor cells. Due to the similarities with a structure known from embryonic development of the vinegar fly Drosophila melanogaster (MEIGEN, 1830), this median region will be referred to as the clypeolabral region (CLR). It gives rise to the larval clypeolabrum and comprises the anlagen of the anterior gut and the stomatogastric nervous system. The red flour beetle Tribolium castaneum (HERBST, 1797) has been established as an important model organism for insect head development due to its insect-typical head and its amenability to functional studies. The formation of the CLR in Tribolium involves a previously unnoticed connection between mesodermal cells and the extraembryonic amnion as well as the formation of a fold in the anterior head. The anterior fold separates the ectoderm of both head sides during early embryogenesis and apparently accounts for the generation of the lateral head lobes found in insect embryos. It is probably also responsible for the relocation of anterior cells to a more posterior sub-terminal position. Moreover, it may be involved in the formation of the stomodaeum. Seven genes were found to show a rather exclusive expression pattern in the CLR during embryogenesis. Surrounding head regions are marked by a distinct set of genes, as well. RNA interference-mediated knockdown of several genes expressed in the anterior head and the subsequent analysis of developing larvae and embryonic gene expression patterns led to the establishment of a model for a gene regulatory network of the CLR. While the late expression aspects of the analyzed genes show a high degree of evolutionary conservation throughout arthropods, the genetic interactions during CLR development appear to be only partly conserved between Drosophila and Tribolium. Three genes, Tc-six3, Tc-crocodile (Tc-croc) and Tc-cap'n'collar (Tc-cnc) were identified as most important upstream regulators of CLR development. Tc-six3 is necessary for all anterior ectodermal derivatives, Tc-croc for development of the foregut and Tc-cnc for clypeolabrum formation. I established transgenic animals for ubiquitous expression of Tc-croc and Tc-six3 by using the φC31-based site specific integration system to further test the function of these genes during embryonic head development.de
dc.contributor.coRefereeWodarz, Andreas Prof. Dr.de
dc.subject.topicBiology (incl. Psychology)de
dc.subject.gerTriboliumde
dc.subject.gerKopfentwicklungde
dc.subject.gerInsektenkopfde
dc.subject.gerStomodaeumde
dc.subject.gerLabrumde
dc.subject.gercrocodilede
dc.subject.gercap'n'collarde
dc.subject.gerforkheadde
dc.subject.engTriboliumde
dc.subject.enghead developmentde
dc.subject.enginsect headde
dc.subject.engstomodaeumde
dc.subject.englabrumde
dc.subject.engcrocodilede
dc.subject.engcap'n'collarde
dc.subject.engforkheadde
dc.subject.bk42.23de
dc.identifier.urnurn:nbn:de:gbv:7-webdoc-3633-5de
dc.identifier.purlwebdoc-3633de
dc.affiliation.instituteBiologische Fakultätde
dc.identifier.ppn726543764de


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