dc.contributor.advisor | Bucher, Gregor Prof. Dr. | de |
dc.contributor.author | Kittelmann, Sebastian | de |
dc.date.accessioned | 2013-01-14T15:06:32Z | de |
dc.date.available | 2013-01-30T23:50:28Z | de |
dc.date.issued | 2012-07-26 | de |
dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-000D-EF6C-D | de |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-1446 | |
dc.description.abstract | Insekten 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 der | de |
dc.format.mimetype | application/pdf | de |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | de |
dc.title | Formation of the Clypeolabral Region During Embryonic Head Development of the Red Flour Beetle Tribolium castaneum | de |
dc.type | doctoralThesis | de |
dc.title.translated | Die Entstehung der clypeolabralen Region während der embryonalen Kopfentwicklung des rotbraunen Reismehlkäfers Tribolium castaneum | de |
dc.contributor.referee | Bucher, Gregor Prof. Dr. | de |
dc.date.examination | 2012-06-14 | de |
dc.subject.dnb | 570 Biowissenschaften, Biologie | de |
dc.subject.gok | WK 000 | de |
dc.description.abstracteng | Insects 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.coReferee | Wodarz, Andreas Prof. Dr. | de |
dc.subject.topic | Biology (incl. Psychology) | de |
dc.subject.ger | Tribolium | de |
dc.subject.ger | Kopfentwicklung | de |
dc.subject.ger | Insektenkopf | de |
dc.subject.ger | Stomodaeum | de |
dc.subject.ger | Labrum | de |
dc.subject.ger | crocodile | de |
dc.subject.ger | cap'n'collar | de |
dc.subject.ger | forkhead | de |
dc.subject.eng | Tribolium | de |
dc.subject.eng | head development | de |
dc.subject.eng | insect head | de |
dc.subject.eng | stomodaeum | de |
dc.subject.eng | labrum | de |
dc.subject.eng | crocodile | de |
dc.subject.eng | cap'n'collar | de |
dc.subject.eng | forkhead | de |
dc.subject.bk | 42.23 | de |
dc.identifier.urn | urn:nbn:de:gbv:7-webdoc-3633-5 | de |
dc.identifier.purl | webdoc-3633 | de |
dc.affiliation.institute | Biologische Fakultät | de |
dc.identifier.ppn | 726543764 | de |