Regulation of a Spermatogenesis-Specific Gene

精子发生是一个动态的细胞分化过程，其特征是精子发生过程中精子的数量发生了显著的变化。 基因表达模式。多年来，我们一直在研究精子发生特异性Pgk 2基因， 一个严格调控的组织特异性基因只在减数分裂和减数分裂后表达的模型 生精细胞我们已经利用了独特的可接近的生精细胞谱系， 在减数分裂前、减数分裂和减数分裂后阶段的特定生精细胞类型的纯化群体。这 使我们能够检查与转录调节机制相关的分子参数， 并确定导致转录起始的分子事件的发育顺序， Pgk 2基因。这使我们能够制定有关这一机制的可验证的假设， 监管过程。在这个应用中，我们提出了实验来确定参与的关键因素， 该基因的调控，以表征染色质组成和结构的变化， 该基因的转录激活，最后，评估组织-和基因- 在转录参数的任何其他变化之前，在该基因中形成特定的去甲基化结构域 并评估去甲基化在何种程度上需要预先处理转录激活的基因。 体内Pgk 2基因。这些实验将使我们能够确定因果关系， 与精子发生特异性基因的转录激活相关的调控事件。这将 导致对调节组织特异性基因表达的机制的进一步理解， 一般，特别是精子发生特异性基因表达。

Spermatogenesis is a dynamic process of cellular differentiation that is marked by dramatic changes in patterns of gene expression. For many years we have studied the spermatogenesis-specific Pgk2 gene as a model of a tightly regulated tissue-specific gene expressed exclusively in meiotic and postmeiotic spermatogenic cells. We have exploited the uniquely accessible spermatogenic cell lineage to obtain purified populations of specific spermatogenic cell types at premeiotic, meiotic, and postmeiotic stages. This has allowed us to examine molecular paramters associated with mechanisms of transcriptional regulation, and to determine a developmental order of molecular events that lead up to initiation of transcription of the Pgk2 gene. This has allowed us to formulate testable hypotheses about the mechanisms involved in this regulatory process. In this application, we propose experiments to identify key factors involved in the regulation of this gene, to characterize changes in chromatin composition and structure that precede transcriptional activation of this gene, and, finally, to assess the mechanism by which a tisssue- and gene- specific demethylation domain develops in this gene prior to any other changes in transcriptional parameters and to assess the extent to which demethylaUon is required to predispose transcriptional activation of the Pgk2 gene in vivo. These experiments will allow us to define cause-and-effect relationships among regulatory events associated with transcriptional activation of a spermatogenesis-specific gene. This will lead to an enhanced understanding of the mechanisms that regulate tissue-specific gene expression in general, and spermatogenesis-specific gene expression in particular.