Collaborative Research: RUI: Regulation of the transition from primary to secondary ovarian follicle development by androgens in a teleost model

脊椎动物可受精卵的产生是一个复杂的过程，在这个过程中，一个小的、相对非特化的细胞卵母细胞被提供了各种母体物质，以支持受精和早期胚胎的发育。因此，“卵子质量”的许多方面都是相对较早确定的。“卵子质量”是用来描述一个卵子能够连续受精并产生一个可存活的后代的术语。该项目将使用来自非哺乳动物脊椎动物模型的卵巢来确定卵母细胞的早期生长是如何受激素调节的。由于脊椎动物卵子发育的保守性，该研究将提高对脊椎动物（包括人类和农业重要动物）卵子发育的基础知识，并可能导致开发改进的方法来克服保护和商业水产养殖中圈养鱼类的生殖功能障碍。该项目将整合研究和教育，招募来自加州州立大学富勒顿分校（一个西班牙裔服务机构）的本科生和研究生，与来自华盛顿大学的不同科学家群体以及来自一个联邦机构的研究人员合作。目标是培养下一代科学家如何应用分子工具，生物信息学和组织学来解决生物学问题，同时深入了解动物生理学，内分泌学和生殖学。这项研究将通过已建立的伙伴关系向科学界和公众介绍，为受训者提供服务学习经验。雌性硬骨鱼繁殖的基本生理学，特别是在卵子发生的后期阶段（如卵黄发生、成熟、排卵），已经相当清楚。相比之下，人们对青春期的过渡知之甚少。在卵巢中，当初级生长的卵泡（包含发育中的卵母细胞）被招募到次级生长时，就会发生这种情况。研究人员利用coho salmon卵巢外植体的体外模型表明，11-酮睾酮（11KT），一种硬骨鱼特异性芳香化雄激素，促进原发性和早期继发卵巢卵泡的发育，这与通过RNA-Seq鉴定数百至数千个基因mRNA水平的改变有关，这取决于阶段。这些变化与激素信号通路改变、组织重塑和早期继发性卵巢卵泡表型的进展一致。该项目将进一步探索雄激素对早期卵巢卵泡至关重要的假设，利用蛋白质组学、定量类固醇生化分析和同源重组促性腺激素的可用性来：表征雌性coho salmon在青春期开始时存在的主要内源性雄激素；表征雄激素受体；使用尖端蛋白质组学记录卵巢卵泡蛋白的发育相关变化；探讨促性腺激素在调节卵泡发育前的潜在作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Production of a fertilizable vertebrate egg is a complex process in which a small and relatively unspecialized cell, the oocyte, is provisioned with a variety of maternal materials that support fertilization and early embryonic development. Thus, many aspects of "egg quality", the term used to describe an egg that can be successively fertilized and lead to a viable offspring, are determined relatively early. The project will use ovaries from a non-mammalian vertebrate model to determine how early oocyte growth is regulated by hormones. Because of the conserved nature of egg development in vertebrates, the research will improve fundamental knowledge of egg development in vertebrates, including humans and agriculturally important animals, and may lead to the development of improved methods to overcome reproductive dysfunction of captive-reared fish in conservation and commercial aquaculture. The project will integrate research and education by recruiting undergraduate and graduate students from California State University Fullerton, a Hispanic Serving Institution, to work with a diverse group of scientists from the University of Washington, and with researchers from a federal agency. The goal is to train the next generation of scientists how to apply molecular tools, bioinformatics, and histology to biological questions while gaining an in-depth understanding of animal physiology, endocrinology, and reproduction. The research will be presented to the scientific community and to the public via established partnerships to provide trainees with service-learning experience.The basic physiology of female teleost reproduction, particularly during the later stages of oogenesis (e.g., vitellogenesis, maturation, ovulation) is fairly well understood. By contrast, comparatively little is known about the transition into puberty. In the ovary, this occurs when the primary growth ovarian follicles (containing developing oocytes) are recruited into secondary growth. Using a well-characterized in vitro model using coho salmon ovarian explants, the investigators have shown that 11-ketotestosterone (11KT), a teleost-specific aromatizable androgen, promotes the development of primary and early secondary ovarian follicles, associated with identification via RNA-Seq of altered mRNA levels of hundreds to thousands of genes, depending on stage. These changes are consistent with altered hormonal signaling pathways, tissue remodeling, and the progression to an early secondary ovarian follicle phenotype. The project will further explore the hypothesis that androgens are essential for early ovarian follicle by exploiting advances in proteomics, quantitative steroid biochemical analyses and the availability of homologous recombinant gonadotropins to: characterize the major endogenous androgens present in the female coho salmon during the onset of puberty; characterize androgen receptors; document the development-related changes in ovarian follicle proteins using cutting-edge proteomics; and explore the potential roles of gonadotropins in regulating previtellogenic ovarian follicle development.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.