Stage-Specific Germ Cell-Sertoli Cell Interactions

阶段特异性生殖细胞-支持细胞相互作用

• 批准号: 6862638
• 负责人: WILLIAM Wallace WRIGHT
• 金额: $ 33.11万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6862638
• 关键词: Sertoli cells; autoradiography; cell cell interaction; cysteine endopeptidases; gel electrophoresis; gene expression; genetic promoter element; genetic transcription; genetically modified animals; germ cells; immunoprecipitation; laboratory mouse; laboratory rat; northern blottings; phase contrast microscopy; spermatogenesis; testis; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): Interactions between developing male gametes and adjacent Sertoli cells are essential for spermatogenesis. Sertoli cells express genes encoding cell adhesion molecules, growth factors, transport proteins, proteases and protease inhibitors required by male germ cells. Germ cells regulate expression by Sertoli cells of many of these genes. Consequently, expression of these genes changes as the adjacent germ progress through the stages of the cycle of the seminiferous epithelium. This application examines the regulation and biological consequences of stage-specific gene expression by Sertoli cells from the perspective of the cathepsin L gene. Transcription of this gene increases more than 10-fold as adjacent germ cells progress from stage I to stages VI and VII and then decreases to undetectable levels when germ cells reach stage X. This cycle of gene expression is a response to germ cells which causes sequential repression, stimulation and re-repression of transcription of the cathepsin L gene. We have identified 2 domains in the cathepsin L gene that potentially respond to these signals: [1] An upstream repressor domain responds to inhibitory signals from germ cells [2] A 120 bp activation domain is stimulated upon the culmination of testis maturation, which is characterized by the completion of the first wave of spermatogenesis. These domains are functional in vivo; a 3kb fragment of the cathepsin L gene confers both Sertoli cell-specific and stagespecific expression of a reporter in transgenic mice. This application also proposes to examine the function of cathepsin L in the seminiferous epithelium. Those experiments are prompted by our observation that mice which express catalytically inactive cathepsin L exhibit an increased incidence of seminiferous tubule atrophy and produce 30% fewer spermatids in nonatrophic tubules than are produced by control mice. Building on all of these data, this proposal asks four questions which are our specific aims: 1 What are the specific cis-acting elements in the activation domain and what are their functions? 2. What is the identity of the transcription factors that bind to the maturation domain? Is their expression stage-specific amd maturation-dependent? 3. What cis-acting elements and which spermatogenic cells repress cathepsin L promoter activity in Sertoli cells? 4. What is the function of cathepsin L in the seminiferous epithelium?

描述（由申请人提供）：发展中的男配子和相邻的Sertoli细胞之间的相互作用对于精子发生至关重要。 Sertoli细胞表达编码细胞粘附分子，生长因子，转运蛋白，蛋白酶和蛋白酶抑制剂所需的基因。生殖细胞通过许多这些基因的Sertoli细胞调节表达。因此，这些基因的表达随着邻近的细菌的进展而变化，通过生精上皮周期的阶段。该应用研究了Sertoli细胞从组织蛋白酶L基因的角度研究Sertoli细胞对阶段特异性基因表达的调节和生物学后果。随着邻近生殖细胞从I期到VI和VII阶段的发展，该基因的转录增加了10倍以上，然后在生殖细胞达到X阶段时降低至无法检测的水平。基因表达的这种循环是对生殖细胞的反应，对生殖细胞产生顺序抑制，刺激，刺激和重新反应Cathepsin L Gene的转录。我们已经确定了在组织蛋白酶L基因中的2个结构域，可能对这些信号有反应：[1]上游阻遏域对生殖细胞的抑制信号做出反应[2]一个120 bp的激活结构域受到睾丸成熟的高潮的刺激，这是由首次精子发生的第一波验证的表征。这些域在体内起作用。组织蛋白酶l基因的3KB片段同时赋予了转基因小鼠中记者的Sertoli细胞特异性和特异性表达。该应用还建议检查组织蛋白酶L在生精上皮中的功能。这些实验是由我们的观察结果引起的，即表达催化性无活力的组织蛋白酶L的小鼠表现出比对照小鼠产生的非养生小管中的生精小管萎缩的发生率增加，而在非养生小管中的精子却少30％。在所有这些数据的基础上，该提案提出了四个问题，这是我们的具体目的：1激活域中的特定顺式作用元素是什么？它们的功能是什么？ 2。与成熟域结合的转录因子的身份是什么？它们的表达阶段特异性AMD成熟依赖性吗？ 3。哪些顺式作用元素和哪些精子生成细胞抑制sertoli细胞中的组织蛋白酶L启动子活性？ 4。在生精中性上皮中，组织蛋白酶L的功能是什么？