Reuter

Project Title: Epigenetic control of pluripotency in Drosophila primordial and ovarian germ line stem cells

There is substantial progress in understanding molecular processes controlling formation, maintenance and differentiation of germ line stem cells in Drosophila whereas epigenetic control of cellular identity and developmental progression is largely unknown. Drosophila PGCs and ovarian GSCs are especially suitable model systems for resolving epigenetic processes in germ line stem cells. Based on our results of a study of histone modifications in PGCs and GSCs, first functional studies of histone methyltransferases and demethylases, an establishment of genetic systems for monitoring gene silencing in female germ line cells and for isolation of germ line chromatin for ChIP we will focus our work on functional dissection of epigenetic processes controlling pluripotency in PGCs and ovarian GSCs. Genes controlling epigenetic processes in Drosophila were identified by Su(var) and E(var) mutations of gene silencing in PEV. Using this large collection of mutant material we will study the control of epigenetic marks, molecular mechanisms of gene silencing, chromatin regulation and epigenetic programming in germ line cells and will combine these studies with ChIP analysis at specific genomic regions as well as genome wide in PGCs and ovarian GSCs. (PGC - primordial germ line cell; GSC - germ line stem cell; ChIP- chromatin immunoprecipitation).

Figure Legend: Immunocytological analysis of histone modification in primordial germ line cells (pole cells- arrow heads) of early Drosophila embryos.

Figure 2: Germ line stem cells with their niche. Electron microscopic visualisation of GSCs (photo Dr. Gerd Hause, Biocenter, Martin Luther Univ. Halle-Wittenberg).