%0 Generic
%A Gavriouchkina, Daria
%D 2012
%F heidok:13036
%K Platynereis , single cell amplification , cell culture , transcriptomics , circadian , light induced , zebrafish
%R 10.11588/heidok.00013036
%T The Platynereis cell : from morphology to single-cell amplification
%U https://archiv.ub.uni-heidelberg.de/volltextserver/13036/
%X All organisms are composed of cells. These cells display a plethora of different morphologies and functions. Since their discovery in their in the seventeenth century their secrets and mysteries have fascinated philosophers and natural scientists alike. In the first part of this thesis I describe experiments performed on a very curious organism; the zebrafish, Danio rerio, whose every cell can carry out a function relegated to only a few chosen cells in other organisms - that of light perception. In order to investigate this phenomenon a genome-wide screen for light-induced genes and miRNAs was performed in the zebrafish embryo, at a stage when photoreceptive organs or structures were not present yet . We revealed the regulatory mechanism that controls these processes. Using a computational approach in combination with knock down and over expression studies we demonstrate that the PAR bZip transcription factor TEF a plays a key role in the regulation of the majority of light-induced genes during early zebrafish development. Since we show that tef alpha! transcription is under circadian clock control, our data suggest that fish embryos anticipate the daily exposure to radiation and the ensuing damage. This capacity to respond to light directly is common to all zebrafish cells but is restricted to only a chosen few in many organisms, in which specific cells called photoreceptors are required for either circadian or non-circadian light perception. Cells categorized as a function of their function, morphology or gene expression are called cell types. Considerable interest has been taken in the evolutionary conservation of cell types between different phyla. In the second part of this thesis, I present work performed in the lab of Dr. Detlev Arendt on the marine polychaete worm Platynereis dumerilii, performing exploratory method development to dissociate larval and adult worm into individual cells in the most efficient fashion, followed by characterization of the resulting single cell suspensions using morphological and molecular methods. Attempts at cell culture from Platynereis dumerilii larval and adult cells as well as other marine organisms are described, demonstrating that primary cell culture can be achieved in these organisms but that further effort is necessary to identify appropriate conditions necessary for the proliferation and survival of these cells.