Epigenetic control of spermatogonial stem cell self-renewal

项目摘要 在精原干细胞更新的驱动下，雄性在整个成年期持续产生精子 （SSC）。本申请的长期目标是确定一种新的表观遗传程序的作用， 我们最近在调节成体SSC的更新中发现了这一点。SSCs既能自我更新， 将分化以启动精子发生的祖精原细胞。SSC自身之间的平衡 更新和分化是成年男性终生产生精子的关键。SSC移植和 体外SSC培养使SSC的功能研究成为可能，并允许促进SSC的翻译。 在动物转基因中的应用。然而，虽然对精子发生了解很多，但精子发生的调节 对南南合作的自我更新仍然知之甚少。干细胞更新需要干细胞内在因子， 外部生态位因素，其中只有少数已被确定（PLZF，RB，NANOS2，GDNF，ETV5等）。 值得注意的是，它们在SSC自我更新中的功能已通过遗传研究揭示。尽管有这些 尽管取得了一些进展，但对SSC的分子生物学控制仍然知之甚少。我们确定了一个 表观遗传因子DOT1L，唯一的H3K79甲基转移酶，作为小鼠SSC自我调节的一种新的主调节因子， 退款此外，通过化学抑制DOT1L，我们能够鉴定出可能 促进南南合作的复兴。我们提出了一个创新的多管齐下（遗传，化学，基因组， 蛋白质组学）方法来全面阐明SSCs中这种新的表观遗传程序。由于SSC失效， 自我更新导致精子生产不足，从而导致男性不育，该项目的完成将奠定一个 为SSC干细胞更新的分子解剖奠定了坚实的基础，并开辟了SSC研究的新途径 生物学和生殖医学。

Project Summary Males produce sperm continuously through adult life, driven by the renewal of spermatogonial stem cells (SSCs). The long-term objective of this application is to determine the role of a novel epigenetic program that we have recently identified in regulating the renewal of adult SSCs. SSCs can both self-renew and produce progenitor spermatogonia that will differentiate to initiate spermatogenesis. The balance between SSC self- renewal and differentiation is key for life-long production of sperm in adult males. Both SSC transplantation and in vitro SSC cultures have enabled functional studies of SSC and allowed for advancement of translational applications in animal transgenesis. However, while much is known about spermatogenesis, the regulation of SSC self-renewal remains poorly understood. Stem cell renewal requires both stem cell-intrinsic factors and external niche factors, only a handful of which have been identified (PLZF, RB, NANOS2, GDNF, ETV5, etc.). Notably, their functions in SSC self-renewal have been revealed through genetic studies. Despite these advances, the molecular biological control of SSC remains poorly understood. We have identified an epigenetic factor DOT1L, the sole H3K79 methyltransferase, as a novel master regulator of mouse SSC self- renewal. Moreover, by chemically inhibiting DOT1L, we were able to identify specific target genes that likely contribute to SSC renewal. We propose an innovative multi-pronged (genetic, chemical, genomic, and proteomic) approach to comprehensively elucidate this novel epigenetic program in SSCs. As failure in SSC self-renewal leads to a lack of sperm production and thus male infertility, completion of this project will lay a firm foundation for molecular dissection of SSC stem cell renewal and open new avenues of research in SSC biology and reproductive medicine.