RFamide Influence on Gonadal Activity

下丘脑促性腺激素释放激素(GnRH)最初是从哺乳动物和包括鸟类在内的非哺乳动物中分离出来的，神经肽对促性腺激素分泌的控制主要是通过下丘脑十肽的刺激作用来实现的。尽管对不同形式的促性腺激素释放激素及其受体的研究揭示了其功能的丰富信息，但直到最近，在任何脊椎动物中，对促性腺激素释放的抑制性下丘脑神经肽仍是未知的。2000年，一种新的雷法米特神经肽被发现特异性地抑制促性腺激素的释放(Tsutsui等人，2000年)。这种多肽现在被命名为促性腺激素抑制激素(GnIH)。促性腺激素抑制系统是一个耐人寻味的概念，为从全新的角度研究生殖调控提供了前所未有的机会。PI实验室的最新发现表明，除了在大脑中合成外，鸣禽的雄性和雌性性腺中也合成了GnIH。此外，GnIH受体在两性的性腺中都有表达。GnIH及其受体在性腺中的表达为生殖系统对环境线索的反应提供了额外的控制水平的框架。因此，了解GnIH及其受体在性腺中表达的原因对脊椎动物生殖生物学领域具有普遍意义。目前，对性腺中的这种激素系统几乎一无所知。本研究以禽性腺GnIH及其受体为研究对象，为进一步研究下丘脑-垂体-性腺轴的相互作用提供可靠的基础数据。如果没有性腺GnIH的基本数据，它的位置和功能，就不能正确地解释脑-性腺的相互作用。这项研究的更广泛影响包括在不同国家的实验室培训研究生，本科生参加研究和科学会议，以及将应得的本科生作为作者纳入出版物。此外，所获得的结果的智力价值包括促进我们对一种新的激素系统的理解，该系统影响到迄今所研究的所有脊椎动物的生殖。关于大脑中的GnIH已经知道了很多，但神经性GnIH如何与性腺GnIH相互作用来计时生殖努力尚不清楚。该项目将提供坚实的数据，在此基础上可以更深入地了解这一新发现的激素系统。

Neuropeptide control of gonadotropin secretion at the level of the anterior pituitary gland is primarily through the stimulatory action of the hypothalamic decapeptide, gonadotropin-releasing hormone (GnRH), which was originally isolated from mammals and subsequently from non-mammals including birds. Although studies of the different forms of GnRH and its receptors have revealed a wealth of information as to their function, an inhibitory hypothalamic neuropeptide for gonadotropin release has, until recently, remained unknown in any vertebrate. In 2000, a novel RFamide neuropeptide was found specifically to inhibit gonadotropin release in quail (Tsutsui et al., 2000). This peptide has now been named gonadotropin-inhibitory hormone (GnIH). A gonadotropin inhibitory system is an intriguing concept and provides an unprecedented opportunity to study the regulation of reproduction from an entirely novel standpoint. Recent findings in the PI's laboratory indicate that in addition to synthesis in the brain, GnIH is also synthesized in male and female gonads of songbirds. In addition, the receptor for GnIH is expressed in the gonads of both sexes. Expression of both GnIH and its receptor in the gonads provides the framework for an additional level of control of the reproductive system in response to environmental cues. Thus, it would be beneficial to the field of vertebrate reproductive biology in general to understand why GnIH and its receptor are expressed in the gonads. At present, almost nothing is known about this hormone system in the gonads. This project focuses on GnIH and its receptor in avian gonads in order to provide solid baseline data for further studies on the interactions of the hypothalamo-pituitary-gonadal axis. Without fundamental data on gonadal GnIH, its location and function, interpretations about brain-gonad interactions cannot be made correctly. The broader impacts of this research include training of graduate students in laboratories in different countries, undergraduate participation in research and scientific meetings, and inclusion of deserving undergraduates as authors on publications. Furthermore, the intellectual merit of the results obtained includes advancement our understanding of a novel hormone system which influences reproduction in all vertebrates studied to date. A great deal is known about GnIH in the brain, but how neural GnIH interacts with gonadal GnIH to time reproductive effort is unknown. This project will provide solid data upon which a deeper understanding of this newly-identified hormone system can be built.