摘要
Homeobox genes encode DNA-binding proteins that regulate the transcription of subordinate downstream genes. In this study, we show that the Pem homeobox gene is expressed and regulated in a unique manner in neonatal and adult rats. Pem gene expression was primarily confined to reproductive tissue: epididymis, testis, ovary, and placenta. In the epididymis, Pem transcripts were localized by in situ hybridization analysis to the proximal cauda region, a site where spermatozoa gain fertilization competence. Pem mRNA levels dramatically increased between Days 21 and 26 postpartum in the epididymis, coincident with the induction of genes known to be responsive to testosterone (T), but in contrast to that of other genes examined, including the Hoxc-8 homeobox gene. Pem expression was shown to be T-dependent on the basis of an absence of Pem transcripts in the epididymides of hypophysectomized rats and restoration of normal Pem mRNA levels after administration of T. In the testis, Pem mRNA levels were elevated earlier (between Days 12 and 15 postpartum) and less dramatically than in epididymis. Pem gene expression in the testis was depressed after hypophysectomy, but normal levels of Pem expression were not restored by T treatment under the same conditions that permitted normal Pem expression in the epididymis. To our knowledge Pem is the first reported putative transcription factor that has been demonstrated to depend on androgens for expression in the epididymis, and thus Pem is a candidate as a regulator of androgendependent events in this tissue.
摘要译文
同源框基因编码调节下游下游基因转录的DNA结合蛋白。在这个研究中，我们显示Pem同源框基因在新生和成年大鼠中以独特的方式表达和调节。 Pem基因表达主要局限于生殖组织：附睾，睾丸，卵巢和胎盘。在附睾中，Pem转录本通过原位杂交分析定位于近端马尾区域，即精子获得受精能力的位置。产后第21天和第26天Pem mRNA水平在附睾中显着增加，与已知对睾酮（T）有反应的基因的诱导同时发生，但与其他检查的基因相比，包括Hoxc-8同源框基因。基于垂体切除大鼠的附睾中Pem转录物的缺失和施用T后正常Pem mRNA水平的恢复，m表达显示为T依赖性。在睾丸中，Pem mRNA水平较早（在产后第12天和第15天之间）升高，并且比附睾中的显着降低。垂体切除术后睾丸中Pem基因表达下降，但是在允许附睾中正常Pem表达的相同条件下，T处理不能恢复正常水平的Pem表达。据我们所知，Pem是第一个被证明依赖于雄激素在附睾中表达的假定转录因子，因此，Pem是该组织中雄激素依赖性事件的调节剂的候选者。
J. Suzanne Lindsey; Miles F. Wilkinson. An Androgen-Regulated Homeobox Gene Expressed in Rat Testis and Epididymis[J]. Biology of Reproduction, 1996,55(5): 975–983