Untersuchungen epigenetischer Effekte von Modellsubstanzen in embryonalen Stammzellen

Epigenetics is a field of genetics that deals with the study of heritable changes in gene functions that are not caused by changes in the DNA sequence, but by covalent modifications of DNA and associated proteins. The modification of the DNA may be induced by DNA methylation, by histone modification or by non coding RNAs. During embryonic development these mechanisms play an especially important role. Demethylation or remethylation processes enable the differentiation of pluripotent cells. How sensitive this phase of epigenetic reprogramming during development is, is demonstrated by the example of diethylstilbestrol, since this substance causes very severe damages during the formation of certain organs in the developing organism. Therefore, one aim of this work was to examine which genes are involved in producing this negative effects of diethylstilbestrol. Another aim was to investigate whether embryonic stem cells, or whether the system of the embryonic stem cell test are suitable for analysing epigenetic modifications. Various kits with which the examination of the overall methylation of the genome and single gene methylation was performed confirmed this presumption. However, it was observed that the analysis of the single gene methylation produced more significant results than the investigation of the overall methylation. The search for genes that were affected by diethylstilbestrol, revealed 5 genes. Cdx2, NeuroD, Pax4, Lefty1 and somatostatin are candidates that should be further analysed in order to investigate their interaction with diethylstilbestrol accurately