REGULATION OF POMC GENE IN TESTIS AND EPIDIDYMIS

我们研究的目的是了解特定基因是如何 在雄性生殖组织中表达和调节。 在这一提议中， 阿黑皮素原（POMC）将用作模型系统。 POMC， 促肾上腺皮质激素、β-内啡肽和黑素细胞刺激的前体蛋白 激素，在许多组织中得到了很好的表征。 我们最近 睾丸和附睾中POMC样mRNA的存在 表明POMC基因的表达和POMC肽的合成， 这些组织。 由于特定基因表达的调节在 睾丸间质细胞或附睾尚未得到很好的理解，我们选择了 研究POMC基因在这些组织中的表达调控。 我们的第一个具体目标是在体内和体外研究 调节POMC mRNA水平和POMC肽合成、加工， 睾丸和附睾中的分泌，使用已知影响 Leydig细胞的功能（促性腺激素，催乳素LHRH类似物等）或 附睾（雄激素、睾丸液）。 POMC mRNA的调控及其与细胞凋亡的关系 肽水平也将在细胞水平上进行检测， cDNA杂交组织化学技术。 第二个具体目标是 了解POMC mRNA变化的分子机制 调制器的水平。 为了回答这个问题，我们将确定 通过核转录测定POMC mRNA的合成速率 POMC基因的活性或POMC mRNA的稳定性将被改变， 调制器。 最后，表达的异质性POMC mRNA的结构 睾丸和附睾中的肿瘤 POMC样mRNA 在睾丸、附睾或Leydig细胞系中发现的大约 150-200个碱基短于垂体或下丘脑。 为了了解在生产过程中涉及的机制异质 POMC mRNA在不同组织中的表达，我们将确定POMC mRNA的结构 通过cDNA克隆和DNA测序分析，表征POMC基因 从大鼠基因组文库中分离，并鉴定转录单位 POMC基因及其核前体mRNA的加工途径。 建议的研究将提供有用的信息，研究 睾丸间质细胞和附睾中特定基因表达的调节。 此外，由于POMC是几种肽激素的前体， 神经递质，拟议的研究将有助于我们了解 这些来自POMC的单独肽的生物学作用， 男性生殖生理学

The objective of our research is to understand how a specific gene is expressed and regulated in male reproductive tissues. In this proposal, proopiomelanocortin (POMC) will be used as a model system. POMC, which is a precursor protein for ACTH, beta-endorphin and melanocyte-stimulating hormones, has been well characterized in many tissues. Our recent demonstration of the existence of POMC-like mRNA in testis and epididymis suggests the expression of a POMC gene and synthesis of POMC peptides in these tissues. Since the regulation of a specific gene expression in Leydig cells or epididymis has not yet been well understood, we have chosen to investigate the regulation of POMC gene expression in these tissues. Our first specific aim is to investigate both in vivo and in vitro the regulation of POMC mRNA level and POMC peptide synthesis, processing, and secretion in testis and epididymis by using factors known to affect functions of Leydig cells (gonadotropins, prolactin LHRH analogs, etc.) or epididymis (androgen, testis fluid). The regulation of POMC mRNA and its peptide levels will also be examined at cellular levels by using in situ cDNA hybridization histochemistry technique. Our second specific aim is to understand the molecular mechanisms involved in the change of POMC mRNA level by modulators. To answer this question, we will determine whether the rate of synthesis of POMC mRNA as measured by nuclear transcriptional activity of the POMC gene or the stability of POMC mRNA will be altered by modulators. Finally, the structure of heterogeneous POMC mRNAs expressed in the testis and epididymis will be characterized. The POMC-like mRNAs found in the testis, epididymis, or Leydig cell lines are approximately 150-200 bases shorter than those found in the pituitary or hypothalamus. To understand the mechanism involved in the production of heterogeneous POMC mRNA in different tissues, we will determine the POMC mRNA structure by cDNA cloning and DNA sequencing analysis, characterize POMC gene(s) isolated from rat genomic libraries, and identify the transcription unit of POMC gene and the pathway of processing nuclear precursor of POMC mRNA. The proposed research will provide useful information in studying the regulation of a specific gene expression in Leydig cells and epididymis. In addition, since POMC is a precursor for several peptide hormones and neurotransmitters, the proposed research will facilitate our understanding of the biological role of these individual peptides derived from POMC in the male reproductive physiology.