FUNCTIONS OF ZINC FINGER GENES ON SEX CHROMOSOMES

锌指-Y（ZFY）基因已从性别决定中鉴定出来 区域的人类Y染色体，并假定为候选基因， 睾丸决定因子（TDF）高度同源基因（ZFX） 在X染色体上也有发现。ZFY和ZFX序列都是 存在于其他哺乳动物的性染色体上。表达研究 确定ZFY基因在成年睾丸中以高水平转录， 但在体细胞组织和胎儿睾丸中含量最低。而且 ZFY和ZFX基因的差异表达是离散大小的， 成年性腺和体细胞组织中的转录本。这些结果提出了一个 关于ZFY基因是否是主要的性别决定基因的重要问题 基因和/或精子发生基因。 拟议研究的主要目的是阐明 Zfy和Zfx基因在睾丸决定和精子发生中的作用。我们计划 把我们的研究集中在两个物种上，老鼠和旅鼠。 小鼠的性别决定已经在遗传水平上得到了很好的表征， 许多菌株在性别决定上发生了突变， 精子发生可用。林旅鼠体内有一个变异的X染色体 染色体，命名为X*，它诱导X*Y动物发育成 女性初步研究表明，Zfx* 基因在分子上是不同的， 来自Zfx基因我们计划使用重组DNA方法来表征 这两个物种的Zfy和Zfx基因。我们会分离并排序 它们的组织特异性全长cDNA，以产生各自的 重组蛋白，并产生相应的组织特异性 抗体的我们将阐明这些木材之间 旅鼠Zfx和Zfx* 基因。我们将研究Zfy和Zfx的表达 正常和异常胚胎发生和精子发生过程中的基因。我们将 将表达模式与它们在这些疾病中的假定作用相关联， 流程.此外，我们计划通过以下方式验证和定义这些角色： 转基因小鼠测定。我们将培育出转基因小鼠， 改变Zfy和Zfx基因的形式，并试图破坏正常的 通过基因打靶等手段， 我们希望观察到异常的性别决定和/或精子发生 在转基因动物中。我们认为， Zfy和Zfx基因的基因和蛋白质结构， 它们在正常、异常和转基因动物中的表达模式将 提供了重要的信息，他们可能在哺乳动物睾丸的作用 决定、分化和精子发生。这些信息将 在性腺发育不全的临床评价中很重要， 男性不育症

The zinc finger-Y (ZFY) gene has been identified from the sex determination region of the human Y chromosome, and postulated as the candidate gene for the testis determining factor (TDF). A highly homologous gene (ZFX) has also been identified on the X chromosome. Both ZFY and ZFX sequences are present on the sex chromosomes of other mammals. Expression studies establish that ZFY genes are transcribed at high levels in adult testis, but at minimal levels in somatic tissues and fetal testes. Furthermore, the ZFY and ZFX genes are differentially expressed as discrete sized transcripts in adult gonadal and somatic tissues. These results raise an important question on whether the ZFY gene is the primary sex determining gene and/or a spermatogenic gene in mammals. The main objective of the proposed studies is to elucidate the functions of the Zfy and Zfx genes in testis determination and spermatogenesis. We plan to concentrate our studies on two species, the mouse and the wood lemming. Sex determination in mouse has been well characterized at genetic levels, and many strains with mutations in their sex determination and spermatogenesis are available. The wood lemming contains a mutated X chromosome, designated X*, which induces X*Y animals to develop into females. Preliminary studies showed that Zfx* gene is molecularly distinct from the Zfx gene. We plan to use recombinant DNA methods to characterize the Zfy and Zfx genes in these two species. We will isolate and sequence their tissue-specific full-length cDNAs, to produce the respective recombinant proteins, and to generate the corresponding tissue-specific antibodies. We will elucidate the molecular differences between the wood lemming Zfx and Zfx* genes. We will study the expression of the Zfy and Zfx genes during normal and abnormal embryogenesis and spermatogenesis. We will correlate the expression patterns to their putative roles in these processes. In addition, We plan to verify and define such roles through transgenic mice assays. We will generate transgenic mice harboring various forms of altered Zfy and Zfx genes, and also attempt to disrupt the normal functions of the endogenous genes through gene targeting and other means. We hope to observe abnormal sex determination and/or spermatogenic activities in the transgenic animals. We believe the proposed studies of the Zfy and Zfx genes in terms of their gene and protein structures and their expression patterns in normal, abnormal and transgenic animals will provide significant information on their probable roles in mammalian testis determination, differentiation and spermatogenesis. This information will be important in the clinical evaluation of gonadal dysgenesis and infertility in man.