TRANSCRIPTIONAL REGULATION OF GONADOTROPIN BETA SUBUNITS DURING DEVELOPMENT

发育过程中促性腺激素β亚基的转录调控

• 批准号: 6241349
• 负责人: MICHAEL W WOLFE
• 金额: $ 9.75万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 1998-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6241349
• 关键词: chorionic gonadotropin; developmental genetics; follicle stimulating hormone; gene expression; genetic promoter element; genetic transcription; genetically modified animals; gonadotropin releasing factor; gonadotropins; hormone regulation /control mechanism; laboratory mouse; luteinizing hormone; nucleic acid sequence; pituitary gland; reporter genes

The gonadotropins, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and chorionic gonadotropin (CG), are essential to mammalian reproduction. LH and FSH are synthesized and secreted from the anterior pituitary gland function to regulate gonadal gametogenesis and steroidogenesis, while CG is synthesized and secreted from the placenta and has a role in maintaining pregnancy. The gonadotropins are heterodimeric glycoprotein hormones composed of a common alpha-subunit noncovalently linked to a unique beta-subunit. A considerable amount of attention has been focused on regulation of expression of the alpha- subunit gene, however, little is known about the mechanisms that regulate expression of the gonadotropin beta-subunits. This has been due to a lack of cell lines that express gonadotropin beta-subunits. Transgenic mice have proven to be extremely valuable for the study of the alpha-subunit and recently have been reported to be a useful model in which to investigate regulation of the beta-subunits. These studies have examined transgene expression in adult mice, but have failed to address spatiotemporal expression patterns. The overall goal of the present proposal is to identify regions in the LHbeta and FSHbeta proximal promoters that direct the appropriate spatiotemporal pattern of expression in transgenic mice. Accordingly, experiments have been proposed to: 1) identify the segment of the equine LH/CGbeta-subunit gene that directs the correct spatial and temporal pattern of expression in the pituitary and to determine whether this region of the gene is also responsible for GnRH regulation of gene expression, and 2) define a small region of the ovine FSHbeta-subunit proximal promoter that retains the correct temporal pattern of gonadotrope-specific expression. Transgenes will be evaluated in adult mice for gonadotrope-specific expression and during embryonic development for the correct onset of expression as well as gonadotrope-specific expression. This segment of proximal promoter must then contain the DNA response elements responsible for directing the correct pattern of gene expression. These promoter fragments will subsequently serve as valuable test constructs in which the physiological relevance of various cis- elements can be evaluated. Several such elements have been identified in the eLH/CGbeta and oFSHbeta proximal promoters and await such testing. The functional significance of these putative elements in the oFSHbeta gene have not been determined.

促性腺激素、黄体生成素、卵泡刺激素 卵泡刺激素(FSH)和绒毛膜促性腺激素(CG)是哺乳动物的必需激素 繁殖。黄体生成素和卵泡刺激素是从大脑的前部合成和分泌的。 脑垂体腺功能调节性腺配子发生和 类固醇生成，而CG是从胎盘合成和分泌的 并在维持妊娠方面发挥作用。促性腺激素是 由一个共同的α-亚基组成的异二聚体糖蛋白激素 非共价连接到一个独特的β-亚基。相当数量的 人们的注意力集中在对α-受体表达的调控上。 然而，亚单位基因对调控机制知之甚少。 促性腺激素β亚基的表达。这是由于缺乏 表达促性腺激素β亚基的细胞系。转基因小鼠 已被证明对阿尔法亚基的研究非常有价值 最近被报道为一种有用的模式，在这种模式下 研究β-亚基的调节。这些研究已经检验了 转基因在成年小鼠中的表达，但未能解决 时空表达模式。 本提案的总体目标是确定 LHbeta和FSHbeta近端启动子引导适当的 转基因小鼠的时空表达模式。因此， 已经提出了以下实验：1)识别马的节段 黄体生成素/降钙素基因--引导正确时空方向的亚单位基因 在脑下垂体的表达模式，并确定这是否 该基因的区域也负责GnRH对基因的调节 表达，以及2)定义绵羊FSHβ亚基的一个小区域 近端启动子保留了正确的时间模式 促性腺激素特异性表达。转基因将在成人中进行评估 小鼠促性腺激素特异性表达及胚胎发育 对于正确的表达开始以及促性腺激素特异性 表情。这段近端的启动子必须含有DNA 负责引导正确基因模式的反应元件 表情。这些启动子片段随后将成为有价值的 测试结构，其中各种顺式的生理相关性- 可以对元素进行评估。有几个这样的元素已经在 ELH/CGbeta和oFSHbeta近端启动子，并等待这样的测试。 卵泡刺激素β亚基中这些假定元件的功能意义 基因还没有确定。