Analysis of the dynamics of epigenetic modifications during Drosophila germ line development

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Germ cells maintain life through the transmission of genetic information into the next generation. Germ cells have the potential to develop into any tissue, making it critical that they are protected from inappropriate differentiation. The mechanisms that provide this protection are unknown and are likely to be relevant to understanding how somatic stem cells maintain pluripotency. DNA-methylation and histone modifications play a major role in the epigenetic regulation of gene expression. We will analyze the function of these modifications during the segregation of the germ cell lineage from somatic cells, their transcriptional quiescence and the maintenance of their identity during embryonic development of Drosophila melanogaster. The host laboratory has established that Dnmt2 is responsible for the DNA-methylation of the fly genome and that high levels of Dnmt2-mediated methylation exist in pole cells (primordial germ cells). We will now globally analyse the dynamics of DNA-methylation and other epigenetic marks (covalent histone modifications) in developing germ Schaefer cells of both wildtype embryos and embryos mutant for genes involved in establishing and maintaining pole cell identity. This will be complemented by a genomic profiling approach to map Dnmt2 target sequences. The combined results will provide insights into the relevance of epigenetic mechanisms during germ line development.