APOPTOSIS IN GERM CELLS--THE ROLE OF BCL-X

这些研究的长期目标是如果确定如何生存 生精细胞的数量受Bcl-2蛋白家族的调控。 尽管存在对监管的多重影响的可能性 增殖中的生殖细胞中的有丝分裂事件，一个重要的 数据已经建立了大小之间的关联 生精室和早期生殖细胞的数量 不能存活到单倍体阶段。我们最近发现bcl-x是一种 Bcl-2癌基因家族成员，优先表达于 老鼠的睾丸。这项提案的研究集中在监管方面。 表达两种蛋白亚型，即Bclxl和Bclxs，以及 它们在决定生殖细胞存亡中的作用。我们的 研究重点将集中在bcl-x在卵巢癌中表达的独特特征。 生精小管。首先，bcl-x基因将被克隆并具有潜在的 DNA鉴定其近端启动子中的调控元件 序列分析。第二，对异构体的具体规定 BCL-x受雄激素和干细胞生长因子的影响 用高纯度的原代培养模型进行评价 精原细胞和早期精母细胞。第三，政治体制改革的阶段性 将测定bclx在生精小管中的表达，并 干细胞因子和雄激素对bclx表达和DNA的影响 减数分裂前生殖细胞的合成已确定。第四，中国经济的影响 Bc l-2家族成员比例的变化 癌蛋白对精原细胞程序性死亡的影响 检查过了。压抑与压抑的天平的具体变化 诱导细胞死亡将通过特定的抑制作用完成 用反义寡核苷酸方法检测BCL-XL mRNA Bcl2基因在转基因生殖细胞中的过表达特征描述 转bcl2基因的生殖细胞发育和细胞凋亡过程 小鼠将促进研究，以描绘bcl2家族在 雄性生殖细胞存活的基因。从睾丸开始 不育男性的活组织检查通常显示数量减少 增殖和发育的生殖细胞，我们预计这是 研究将产生重要的新数据 细胞凋亡及其对男性生育能力的调节。

The long-term goal of these studies if to determine how the survival of spermatogenic cells is regulated by the Bcl-2 family of onoproteins. Although the potential exists for multiple influences on the regulation of mitotic events in the proliferating germ cells, a significant body of data has established a correlation between the size of the spermatogenic compartment and the number of early germ ells that do not survive to the haploid stage. We recently identified bcl-x as a member of the bcl-2 family of oncogenes preferentially expressed in the rat testis. Studies in this proposal concentrate on the regulation of the expression of two protein isoforms, Bcl-xL and Bcl-xS, and their roles in determining survival versus death of germ cells. Our studies will focus on the unique features of bcl-x expression in the seminiferous tubule. First, the bcl-x gene will be cloned and potential regulatory elements identified in its proximal promoter by DNA sequence analysis. Second, the specific regulation of the isolforms of bcl-x mRNA by androgens and stem cell growth factor will be evaluated using primary culture models of highly purified spermatogonia and early spermatocytes. Third, the stage specificity of bcl-x expression in the seminiferous tubule will be determined and the effects of stem cell factor and androgens on bcl-x expression and DNA synthesis in premeiotic germ cells ascertained. Fourth, the effects of changes in the ratio of the members of the Bcl-2 family of oncoproteins on programmed cell death in spermatogonia will be examined. Specific alterations in the balance of suppression versus induction of cell death will be accomplished by specific inhibition of Bcl-xL mRNA using an antisense oligonucleotide approach and by overexpression of Bcl-2 in transfected germ cells. Characterization of germ cell development and apoptotic processes in the bcl-2 transgenic mouse will facilitate studies to delineate the role of the bcl-2 family of genes in the survival of the male germ cells. Since testicular biopsies rom infertile males often show decreased numbers of proliferating and developing germ cells, we anticipate that this research will lead to significant new data on the relevance of apoptosis and its regulation to human male fertility.