Hormonal control of reproduction in goldfish

这项拟议的研究将继续进行中，并以金鱼为主要实验模型，启动关于荷尔蒙控制脑下垂体和性腺功能的新的研究路线。重点是对涉及脑-垂体-性腺轴的繁殖的综合控制以及对金鱼性腺发育和分化的自分泌/旁分泌调节。主要目标是：研究(1)神经内分泌调节金鱼脑下垂体中促性腺激素(GTH)和生长激素(GH)的产生。重点放在促性腺激素释放激素(GnRH)、性腺类固醇，以及抑制GTH产生的下丘脑RFamide相关多肽家族。我们建议全面研究RFamide及其受体在垂体和垂体外的功能特征，并研究它们与GnRH和性腺类固醇的相互作用。重点是参与卵巢和睾丸早期发育和分化的基因的调节，以及它们与当地产生的GnRH和类固醇的相互作用。因此，阐明介导雌激素、雄激素和甲状腺激素作用的核受体的结构和功能特征是很重要的。本研究的目的是探讨本实验室最近发现的新型核受体形式的调控和功能意义。本研究将为金鱼生殖的内分泌和旁分泌控制提供新的信息，并为更好地了解脊椎动物脑下垂体和性腺功能的神经内分泌控制提供框架。

The proposed research will continue work in progress and initiate new lines of inquiry concerning hormonal control of pituitary and gonadal function, using goldfish as primary experimental model. Emphasis is placed on integrated control of reproduction involving brain-pituitary-gonadal axis as well as autocrine/ paracrine regulation of gonadal development and differentiation in goldfish. The main objectives are:     1) Neuroendocrine regulation of gonadotropin (GTH) and growth hormone (GH) production in the goldfish pituitary. Emphasis is placed on gonadotropin releasing hormone (GnRH), gonadal steroids, and hypothalamic RFamide-related family of peptides that inhibit GTH production. We propose to fully investigate functional characterization of RFamides and their receptors in the pituitary and extrapituitary and  their interaction with GnRH and gonadal steroids.    2) We continue testing the main hypothesis that GnRH plays a role in autocrine/paracrine regulation of gonadal function in goldfish. Emphasis is placed on the regulation of genes involved in early ovarian and testicular development and differentiation and their interaction with locally produced GnRH and steroids.    3) Sex steroids play critical role in the regulation of pituitary and gonadal function. It is therefore important to elucidate structural and functional characterization of nuclear receptors that mediate actions of estrogen, androgen, and thyroid hormones. The objective of the proposed study is to investigate the regulation and functional significance of novel nuclear receptor forms discovered recently in my laboratory.     The propose research will generate novel information on endocrine and paracrine control of reproduction in goldfish as well as providing a framework for better understanding of neuroendocrine control of pituitary and gonadal function in vertebrates.