REPRODUCTIVE BIOLOGY OF GONADOTROPIN REGULATION

黄体生成素和卵泡刺激素的调节 性腺功能和配子发生，对正常的性行为至关重要 发育和生殖功能。黄体生成素和卵泡刺激素被合成并 在脑下垂体促性腺激素的复杂调节下分泌 下丘脑肽，促性腺激素释放激素(GnRH)。长的- 这项建议的任期目标是为了更好地了解 促黄体生成素和促卵泡刺激素亚基差异调控的分子机制 促性腺激素释放激素的基因表达。促性腺激素释放激素是从下丘脑释放的。 脉动时尚，释放频率在整个过程中变化 生殖周期。不同的脉冲频率进行不同的调节 黄体生成素和卵泡刺激素的生物合成和分泌。生殖中的一个主要问题 生理学是这种现象发生的机制。之前的研究已经 由于缺乏表达黄体生成素和黄体生成素的细胞系 FSH亚单位基因，并对GnRH作出反应。我们创造了一种新颖的细胞 进行这些研究的系统，通过将大鼠 含大鼠促性腺激素释放激素受体基因的垂体GH3细胞株。这些细胞， 当与黄体生成素或卵泡刺激素亚单位基因的调节区共转染时 融合到荧光素酶报告基因，对GnRH的反应增加 荧光素酶活性。目前的研究建议侧重于使用 该细胞模型有助于阐明和比较其作用机制。 促性腺激素释放激素对促性腺激素亚单位基因表达的调节在……里面 具体地说，该细胞模型系统将用于：(1)识别 LHBeta基因中介导促性腺激素释放激素反应的关键顺式元件(S)； (2)确定FSHBeta基因的关键顺式元件(S)。 调节促性腺激素释放激素反应，并将其与LHBeta中确定的反应进行比较 基因；(3)鉴定和比较与基因结合的反式因子 LHBeta和FSHBeta中介导GnRH反应的顺式元件 基因；以及(4)确认已识别的GnRH调节机制 LHBeta和FSHBeta基因在原代大鼠垂体细胞或其他细胞中的表达 如果有促性腺激素细胞株的话。预计这些研究将 将为监管的机制提供新的见解 促性腺激素释放激素，这反过来可能提供更好的理解 促进生殖发育，改善对疾病的管理 生殖功能。

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) regulate gonadal function and gametogenesis, and are critical for normal sexual development and reproductive function. LH and FSH are synthesized and secreted from pituitary gonadotropes under complex regulation by the hypothalamic peptide, gonadotropin-releasing hormone (GnRH). The long- term objective of this proposal is to gain a better understanding of the molecular mechanisms of the differential regulation of LH and FSH subunit gene expression by GnRH. GnRH is released from the hypothalamus in a pulsatile fashion, with the frequency of release varying throughout the reproductive cycle. Different pulse frequencies regulate differentially LH and FSH biosynthesis and secretion. A major question in reproductive physiology is the mechanism by which this occurs. Previous studies have been limited by the lack of available cell lines which express the LH and FSH subunit genes and respond to GnRH. We have created a novel cell system in which to perform these studies, by transfecting the rat pituitary GH3 cell line with the rat GnRH receptor cDNA. These cells, when cotransfected with regulatory regions of the LH or FSH subunit genes fused to a luciferase reporter gene, respond to GnRH with an increase in luciferase activity. The present research proposal focuses on the use of this cell model as an aid to elucidate and compare the mechanisms of regulation of gonadotropin subunit gene expression by GnRH. In particular, this cell model system will be used: (1) to identify the critical cis element(s) in the LHBeta gene which mediates GnRH responses; (2) to identify the critical cis element(s) in the FSHBeta gene which mediates GnRH responses and compare it to that identified in the LHBeta gene; (3) to characterize and compare the trans factors that bind to the cis elements which mediate GnRH responsiveness in the LHBeta and FSHBeta genes; and (4) to confirm the identified mechanisms of GnRH regulation of LHBeta and FSHBeta genes in primary rat pituitary cells, or other gonadotrope cell lines when available. It is expected that these studies will provide new insights into the mechanisms of the regulation of gonadotropins by GnRH, which may in turn provide a better understanding of reproductive development and lead to improved management of disorders of reproductive function.