Expression profiling of gonadotropin receptor-related genes

使用几个物种进行了基因表达谱分析，以研究两个促性腺激素受体(FSHR和LHR)在鱼类配子发生中的作用。在青竹卵子发生过程中收集高度同步的卵泡，并对卵子发生相关分子如类固醇代谢酶和促性腺激素受体的mRNA水平进行定量比较。产卵前32h，FSHR基因表达水平显著下降。同时，参与雌激素合成途径的几个基因表达下调。LHR基因表达水平一直维持到产卵前11小时。参与成熟诱导球茎生物合成的基因具有相似的表达谱。结论：1.卵母细胞成熟过程中，孕激素核受体基因的表达呈现出一种独特的模式，并有一过性的升高。分析了FSHR和LHR基因在牙鲆(P.olivaceus)性腺温度依赖性分化中的表达。雄性诱导温度特异性地抑制FSHR、FOXL2和芳香酶的基因表达，提示FSH信号在性别分化中具有新的功能。构建了含FSHR-绿色荧光蛋白(GFP)报告基因的青竹转基因菌株。在该菌株中，仅在性腺支持细胞中检测到荧光。我们将尝试利用这个模型来阐明FSHR的基因调控机制。从大西洋鳕鱼(G.morhua)中克隆了FSHR、LHR和性激素代谢酶基因，并对其在成熟过程中的表达谱进行了分析。用芳香酶抑制剂处理一龄遗传雌性(XX)鲤鱼的卵巢，诱导卵巢组织。这一观察结果表明，在性腺分化后，性色毛类鱼类维持了性双性潜能。已从鲤鱼中克隆了FSHR、LHR的基因，并对其表达谱进行了分析。

Gene expression profiling was performed to address the role of two gonadotrpin receptors (FSHR and LHR) in fish gametogenesis using several species.1. Highly synchronous ovarian follicles were collected from medaka (O. latipes) during the course of oogenesis, and subjected to quantitation of mRNA levels for oogenesis-related molecules such as steroid-metabolizing enzymes in comparison with gonadotropin receptors. FSHR mRNA level dramatically decreased 32 hours before spawning. At the same time, several genes involved in estrogen synthetic pathway were down-regulated. LHR mRNA level was maintained until 11 hours before spawning. Genes involved in the biosynthesis of maturation inducing stroid showed similar expression profiles. Progesterone nuclear receptor mRNA exhibited a unique pattern with a transient increase during oocyte maturation.2. Gene expression of FSHR and LHR were analyzed in the temperature-dependent gonadal sex differentiation of Japanese flounder (P. olivaceus). Male-inducing temperature specifically suppressed the gene expression of FSHR as well as those of Foxl2 and aromatase, suggesting novel functions of FSH signaling in sex differentiation.3. A transgenic medaka strain harboring FSHR-green fluorescent protein (GFP) reporter gene construct was established. In this strain, the fluorescence was detected only in gonadal supportive cells. We will attempt to elucidate the gene regulation mechanism for FSHR using this model.4. cDNAs for FSHR, LHR and sex steroid-metabolizing enzymes were cloned from Atlantic cod (G. morhua) and their expression profiles during maturation were analyzed.5. Testicular tissue was induced in the ovary of one-year-old genetic female (XX) carp by aromatase inhibitor treatment. This observation shows the maintenance of sexual bipotentiality after gonadal sex differentiation in gonochoristic fish. cDNAs for FSHR, LHR have been cloned from carp and their expression profiles will be analyzed.