Control of Stem Cell Fate in Drosophila Spermatogenesis

果蝇精子发生中干细胞命运的控制

• 批准号: 6867276
• 负责人: Erika L Matunis
• 金额: $ 36.08万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6867276
• 关键词: DNA binding protein; Drosophilidae; JAK kinase; biological signal transduction; cell cycle; cell growth regulation; cell population study; developmental genetics; enzyme activity; enzyme inhibitors; gene expression; germ cells; green fluorescent proteins; in situ hybridization; ligands; polymerase chain reaction; spermatogenesis; stem cells; testis

DESCRIPTION (provided by applicant): Although spermatogonial stem cells are essential for reproduction, little is known about their regulation. Environmental and intrinsic factors are crucial for stem cell establishment and maintenance, but systematically identifying these factors is extremely challenging in mammalian systems. We use Drosophila spermatogenesis as a model system, since it parallels mammalian systems, yet we can precisely locate the stem cells, and manipulate their microenvironment genetically. Prior funding enabled us to discover the molecular mechanism controlling Drosophila spermatogonial stem cell self-renewal. Germline stem cells (GSCs) are anchored around a cluster of somatic support cells called the hub. The hub produces a ligand that activates Jak-Stat in adjacent germ cells, instructing them to remain as stem cells. Daughters displaced away from the hub differentiate. Building on preliminary data derived from these findings, in this renewal we address three fundamental questions. In Aim 1, we pursue our preliminary data suggesting that Jak-Stat signaling converts GSC precursors (primordial germ cells) into GSCs by characterizing germ cell behavior and Jak-Stat activity in the embryonic testis, then using genetics to determine the role of this pathway in GSC establishment. In Aim 2, we extend our studies of Jak-Stat signaling in adult stem cells. Although GSCs require direct activation of Stat, this was not tested for SSCs. In Aim 2a, we determine if Jak-Stat signaling is directly or indirectly required for GSC maintenance. In Aim 2b, we pursue our extensive preliminary data indicating that socs36E, a target and inhibitor of Jak-Stat signaling, maintains GSCs in the testis. We will complete the characterization of our socs36E alleles, then we will determine if socs36E is directly or indirectly required for GSC maintenance. Finally, since targets of Stat in GSCs (& possibly SSCs) may be intrinsic determinants of stem cell fate, while targets in hub cells may regulate hub cell function, we will identify these targets, and test them for roles in stem cell maintenance using genetic approaches in Aim 3. Together this work will provide fundamental insight into the molecular mechanisms that regulate stem cell establishment and maintenance, which is of great importance towards developing potential therapeutic uses of stem cells in regenerative medicine.

描述（由申请人提供）：尽管精子干细胞对于繁殖至关重要，但对其调节知之甚少。环境和内在因素对于干细胞的建立和维护至关重要，但是在哺乳动物系统中，系统地识别这些因素是极具挑战性的。我们使用果蝇的精子发生作为模型系统，因为它与哺乳动物系统相似，但是我们可以精确地定位干细胞，并通过基因操纵其微环境。先前的资金使我们能够发现控制果蝇精子干细胞自我更新的分子机制。种系干细胞（GSC）锚定在一个称为中心的体细胞支撑细胞周围。该轮毂产生一种配体，该配体在相邻生殖细胞中激活JAK-STAT，指示它们作为干细胞保留。女儿偏离了轮毂分化。在这些发现的初步数据的基础上，在此续签中，我们解决了三个基本问题。在AIM 1中，我们追求初步数据，表明JAK-STAT信号通过表征胚胎睾丸中的生殖细胞行为和JAK-STAT活性，然后使用遗传学来确定该途径在GSC建立中的作用，从而将GSC前体（原始生殖细胞）转化为GSC。在AIM 2中，我们扩展了对成年干细胞中JAK-STAT信号传导的研究。尽管GSC需要直接激活STAT，但没有对SSC进行测试。在AIM 2A中，我们确定GSC维护是否直接或间接需要JAK-STAT信号传导。在AIM 2B中，我们追求广泛的初步数据，表明SOCS36E（JAK-STAT信号传导的目标和抑制剂）在睾丸中维持GSC。我们将完成SOCS36E等位基因的表征，然后我们将确定SOCS36E是否直接或间接用于GSC维护。最后，由于GSC（及可能是SSC）中统计数据的靶标可能是干细胞命运的固有决定因素，而集线器细胞中的靶标可能会调节HUB细胞功能，我们将确定这些靶标，并测试它们在AIM中使用遗传学的遗传方法中的遗传方法在维持干细胞中的作用3。再生医学中的干细胞。