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

组蛋白修饰标记的分析揭示了PGCs和GSC中特定的表观遗传过程。与胚盘一样，原始生殖细胞的染色质分化也是极性的。H3 K4 me 1和H3 K27 me 2/me 3是丰富的，并且SU（VAR）3-3脱甲基酶确保PGCs中低水平的H3 K4 me 2。Su（var）3-3突变损害GSC的干细胞性和发育。异染色质H3 K9 me 2/me 3标记在PGCs中由SETDB 1控制，在GSC中由SU（VAR）3-9和SETDB 1控制。PGC中丰富的染色质蛋白是SU（VAR）3-3和SU（VAR）2-1，它们与早期染色质蛋白复合物结合。SU（VAR）2-1是PGC和GSC发育所必需的新因子。PGC中的染色质分化受蜕皮激素信号的控制。生殖系干细胞基因沉默的遗传解剖揭示了复杂的表观遗传编程，并证明了许多已知的表观遗传因子在这些过程中的功能。在我们未来的工作中，我们将集中在定义和功能分析的表观遗传因素控制组蛋白修饰的生殖系干细胞。在我们对生殖系干细胞表观遗传过程的分析中，我们将联合收割机遗传技术与生殖系染色质的ChIP分析相结合。

Analysis of histone modification marks revealed specific epigenetic processes in PGCs and GSCs. Like in blastoderm also in PGCs chromatin differentiation is polar. H3K4me1 and H3K27me2/me3 are abundant and the SU(VAR)3-3 demethylase ensures a low level of H3K4me2 in PGCs. Su(var)3-3 mutations impair stemness and development of GSCs. The heterochromatic H3K9me2/me3 marks are controlled by SETDB1 in PGCs and by SU(VAR)3-9 and SETDB1 in GSCs. Abundant chromatin proteins in PGCs are SU(VAR)3-3 and SU(VAR)2-1 associating into an early chromatin protein complex. SU(VAR)2-1 is a novel factor essential for PGC and GSC development. Chromatin differentiation in PGCs is under control of ecdysone signaling. Genetic dissection of gene silencing in germ line stem cells revealed complex epigenetic programming and proved the function of many known epigenetic factors in these processes. In our future work we will focus on defining and functional analysis of epigenetic factors which control histone modifications in germ line stem cells. In our analysis of epigenetic processes in germ line stem cells we will combine genetic techniques with ChIP analysis of germ line chromatin.