A very important open question in stem cells regulation is how the fine balance between GSCs self-renewal and differentiation is orchestrated at the molecular level. In the past several years much progress has been made in understanding the molecular mechanisms underlying intrinsic and extrinsic controls of GSC regulation but the complex gene regulatory networks that regulate stem cell behavior are only partially understood. HP1 is a dynamic epigenetic determinant mainly involved in heterochromatin formation, epigenetic gene silencing and telomere maintenance. Furthermore, recent studies have revealed the importance of HP1 in DNA repair, sister chromatid cohesion and, surprisingly, in positive regulation of gene expression. Here, we show that HP1 plays a crucial role in the control of GSC homeostasis in Drosophila. Our findings demonstrate that HP1 is required intrinsically to promote GSC self-renewal and progeny differentiation by directly stabilizing the transcripts of key genes involved in GSCs maintenance.

干细胞调节中一个非常重要的开放性问题是，如何在分子水平上协调GSCs自我更新和分化之间的良好平衡。在过去的几年中，在理解GSC调节的内在和外在控制的分子机制方面已取得了很大进展，但调节干细胞行为的复杂基因调节网络仅得到部分了解。HP1是动态表观遗传决定簇，主要参与异染色质形成，表观遗传基因沉默和端粒维持。此外，最近的研究表明，HP1在DNA修复，姐妹染色单体内聚以及基因表达的正向调控中具有重要意义。在这里，我们显示HP1在果蝇GSC稳态控制中起着至关重要的作用。我们的发现表明，通过直接稳定参与GSC维持的关键基因的转录本，HP1本质上是促进GSC自我更新和后代分化的必需物质。