Stem Cell Mechanism in the Murine Germline

描述：(申请人提供)我们的长期目标是学习如何 干细胞的自我更新是实现和调节的，这是一个关键的问题 了解组织发育、肿瘤发生、伤口修复、免疫缺陷、 和不孕不育。我们的重点是研究生殖系中的干细胞。通过这样做， 我们希望将我们的研究联系起来，将两个极其重要但高度 生物医学研究的谜团领域-生殖系和干细胞生物学。我们的 方法是建立果蝇作为探索分子的先导系统 干细胞分裂的机制，并扩大我们从中学到的东西 通过反向遗传学方法将果蝇转化为哺乳动物系统。 具体地说，我们已经在果蝇和 发现了控制细胞内和细胞间机制的关键基因 干细胞分裂。此外，我们一直在深入研究这些问题 哺乳动物系统中的基因。这一战略为我们提供了无与伦比的 有机会发现干细胞的基本机制并探索其 医学上的意义。我们的假设是，关键干细胞的功能 基因在进化过程中是保守的。为了支持这一点，我们发现了 第一个也是唯一一个已知的进化保守基因家族，Piwi家族 不同生物体中参与干细胞自我更新的基因 动植物王国。我们在该提案中的工作假设是两个 该基因家族中的小鼠成员miwi和mili参与了 细胞自主机制，控制精原干细胞分裂和 精子发生。我们在这项提案中的具体目标是探索干细胞 通过系统地研究miwi和miii在细胞内的作用机制 精原干细胞分裂及其相关过程。用所有的工具 根据大多数拟议分析的情况和经验，我们计划：1. 描述MILI在生殖系发育过程中的表达。2.分析 通过创建和检查条件零点来实现MII的发育功能 老鼠。3.研究miwi和mili在精原干细胞中的作用 组织。4.分析MIWI和MILL在精原细胞中的生化作用 干细胞分裂。5.确定MIWI和MILL的直接靶基因，以便进一步研究 研究MIWI/MILI介导的机制。

DESCRIPTION: (provided by applicant) Our long term goal is to learn how the self-renewal of stem cells is achieved and regulated, a question crucial to understanding tissue development, oncogenesis, wound repair, immunodeficiency, and infertility. Our focus is to study stem cells in the germline. In so doing, we hope to link our research between two extremely important yet highly enigmatic areas of biomedical research - germline and stem cell biology. Our approach is to establish Drosophila as a pilot system to explore molecular mechanisms underlying stem cell division, and to expand what we learn from Drosophila to mammalian systems via the reverse genetics approach. Specifically, we have identified germline stem cells in Drosophila and discovered key genes that control the intra- and intercellular mechanisms of the stem cell division. Further more, we have been intensively studying these genes in mammalian systems. This strategy has offered us unparalleled opportunities to discover fundamental stem cell mechanisms and to explore their medical significance. Our hypothesis is that the function of key stem cell genes is conserved during evolution. In support of this, we have discovered the first and only known family of evolutionarily conserved genes, the piwi family genes that are involved in stem cell self-renewal in diverse organisms in animal and plant kingdoms. Our working hypothesis in this proposal is that two murine members of this gene family, miwi and mili, are involved in cell-autonomous mechanisms that control spermatogonial stem cell division and spermatogenesis. Our specific aim in this proposal is to explore the stem cell mechanism by systematically characterizing the function of miwi and miii in spermatogonial stem cell division and its related processes. With all the tools in place and experience in most of the proposed analyses, we plan to: 1. Characterize mili expression during germline development. 2. Analyze the developmental function of miii by creating and examining conditional mili-null mice. 3. Characterize the roles of miwi and mili in spermatogonial stem cell division. 4. Analyze the biochemical roles of MIWI and MILl in spermatogonial stem cell division. 5. Identify direct target genes of MIWI and MILl to further study MIWI/MILI-mediated mechanisms.