REGULATION OF POMC GENE IN TESTIS AND EPIDIDYMIS

我们研究的目的是了解一个特定的基因是如何 在男性生殖组织中表达和调控。在这份提案中， 前阿片黑素皮质素(POMC)将被用作模型系统。POMC，这是 促肾上腺皮质激素、β-内啡肽和黑素细胞刺激的前体蛋白 荷尔蒙，在许多组织中都有很好的特性。我们最近 睾丸和附睾中存在POMC样mRNA的证据 提示POMC基因的表达和POMC多肽的合成 这些纸巾。由于对特定基因表达的调节 间质细胞或附睾尚未被很好地了解，我们选择 目的：探讨POMC基因在这些组织中的表达规律。 我们的第一个具体目标是研究体内和体外的 POMC信使核糖核酸水平和POMC多肽的合成、加工和调节 利用已知的影响睾丸和附睾液分泌的因素 间质细胞的功能(促性腺激素、催乳素LHRH类似物等)或 附睾症(雄激素、睾丸液)。POMC mRNA及其转录因子的调控 多肽水平也将通过原位检测在细胞水平上进行 C DNA杂交组织化学技术。我们的第二个具体目标是 了解POMC基因表达变化的分子机制 由调制器调平。为了回答这个问题，我们将确定是否 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，表达了异质性POMC mRNAs的结构 在睾丸和附睾处的特征将是。POMC样蛋白mRNAs 在睾丸、附睾或间质细胞系中发现的大约 比脑垂体或下丘脑短150-200个碱基。 了解异质油产生的机理 在不同的组织中，我们将确定POMC的mRNA结构 通过基因克隆和序列分析，鉴定了pomc基因(S) 从大鼠基因组文库中分离，并鉴定其转录单位 POMC基因及其核前体的加工途径。 建议的研究将提供有用的资料以研究 间质细胞和附睾中一种特定基因表达的调控。 此外，由于POMC是几种多肽激素和 神经递质，拟议的研究将有助于我们理解 这些来源于POMC的单独的多肽在 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.