ROLE OF TESTIS-SPECIFIC HISTONES IN SPERMATOGENESIS

这项拟议工作的长期目标是调查 睾丸特异性组蛋白的生物学作用及其基因调控 在精子发生过程中。 此外，雌激素在 将研究精子发生。 我们将调查是否存在 大鼠睾丸特异性基因周围含有睾丸特异性基因的区域 TH 2A和TH 2B基因，存在睾丸特异性显性控制区 在区域附近，通过核基质结合来定义区域 位点，以及睾丸特异性组蛋白基因的调节， 显性控制区的睾丸特异性增强子活性。 TH2B 基因在精原细胞中转录较差，这可能是由于 一种精原细胞特异性蛋白，结合TATAA盒之间的位点 和TH 2B转录起始位点。 这将被调查 用部分纯化的蛋白质在体外转录系统中进行。 的 TH 1和TH 2B组蛋白在形成更松弛的 粗线期精母细胞的染色质结构将通过 在缺乏H1或H2 B的酵母突变株中产生组蛋白 组蛋白基因 组蛋白分子中负责 染色质结构的变化将通过定点 诱变 此外，TH 1和TH 2B对细胞凋亡率的可能影响也是未知的。 将研究酵母中的减数分裂。 雌激素产生于 睾丸支持细胞中的睾丸激素和女性性激素可能有一个共同的作用。 在精子发生中的直接作用，可能是负调节。 初级 精母细胞含有雌激素受体，这意味着直接作用 雌激素在精子发生中的作用 我们将调查 雌激素对精子发生影响 睾丸支持细胞-生精细胞共培养物的表达及 雌激素. 我们将克隆受雌激素和氨基调节的基因， 将确定基因产物的酸序列。 细胞 表达基因和基因产物将通过在 原位细胞杂交和免疫细胞化学。

The long term objectives of this proposed work are investigations of the biological role of testis-specific histones and regulation of their genes during spermatogenesis. In addition, the role of estrogen in spermatogenesis Will be investigated. We will investigate presence of a domain containing testis-specific genes around the rat testis-specific TH2A and TH2B genes, presence of testis-specific dominant control region near the domain, definition of the domain by nuclear matrix binding sites, and regulation of testis-specific histone genes by the testis-specific enhancer activity of the dominant control region. TH2B gene is poorly transcribed in spermatogonia and this could be due to the spermatogonia-specific protein which binds to a site between TATAA box and the TH2B transcription initiation site. This will be investigated with partially purified protein in an in vitro transcription system. The possible role of TH1 and TH2B histones in the formation of more relaxed chromatin structure in pachytene spermatocytes will be investigated by producing the histones in yeast mutant strains lacking either Hl or H2B histone genes. The regions of the histone molecule responsible for the changes in chromatin structure will be investigated by site-directed mutagenesis. Also, the possible effect of TH1 and TH2B on the rate of meiosis in yeast will be investigated. Estrogen is produced from testosterone in Sertoli cells, and the female sex hormone may have a direct role in spermatogenesis, possibly negative regulation. Primary spermatocytes contain estrogen receptors, and this implies a direct role of estrogen in spermatogenesis. We win investigate the stages of spermatogenesis affected by estrogen in differentiating primary cultures of Sertoli-spermatogenic co-cultures and the proteins regulated by estrogen. We will clone the genes regulated by estrogen and the amino acid sequence of the gene products will be determined. The cells expressing the genes and the gene products will be investigated by in situ cytohybridization and immunocytochemistry.