Endocrine Control of Fish Reproduction

鱼类繁殖的内分泌控制

• 批准号: RGPIN-2020-06134
• 负责人: Peng, Chun
• 金额: $ 3.42万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740710
• 关键词: Endocrine; Control; Fish; Reproduction

Development and maturation of oocytes (eggs) within the ovary are complex events that require the coordination of signaling molecules originating from the brain, pituitary, and ovary. We have been using zebrafish as an experimental model to investigate how the ovarian-derived signaling molecules, particularly members of the transforming growth factor-beta (TGF-beta) family and microRNAs (miRNAs), exert regulatory effects within the ovary to control the development and maturation of eggs. In the next five years, we will extend these studies to investigate the role of Nodal and several specific miRNAs: Aim 1. Physiological roles and signaling mechanisms of Nodal in zebrafish ovary Nodal is a member of the TGF-beta family known to play critical roles in embryonic development. However, its role in ovarian physiology is not known. There are three Nodal related (ndr) genes in zebrafish (ndr1, ndr2, and ndr3). We are using genetic tools to delete these genes individually or in combination and will use these knockout lines to study how these genes are involved in regulating reproduction in female zebrafish. Specifically, we will compare the production of steroid hormones, oocyte maturation, ovulation, spawning, and embryo production between wild type fish and ndr mutants. We will also determine how Nodal exerts the regulatory effects in zebrafish ovary by investigating various signaling pathways induced by Nodal. Aim 2. Role of microRNAs in zebrafish follicle growth and oocyte maturation miRNAs are small non-coding RNAs that play important roles in gene regulation. The role of miRNAs in ovarian development and oocyte maturation is largely unknown. We recently identified many miRNAs that are differentially expressed between stage IIIa (small vitellogenic follicles that are unresponsive to maturation-inducing hormones) and stage IIIb (large vitellogenic follicles that are maturationally competent) follicular cells. We will select four miRNAs that are most strongly decreased in stage IIIb follicular cells to investigate their functions and mode of actions in the ovary. We will develop knockout lines to study the consequences of loss of these miRNAs on follicle development, oocyte maturation, ovulation, spawning, and embryo production. These miRNAs are predicted to target Nodal receptors and signaling components for key hormones involved in oocyte maturation. We will characterize the target genes of these miRNAs to understand how these miRNAs play a role in reproduction. This research program will provide novel insights into how Nodal and miRNAs are involved in the regulation of ovarian physiology in fish and may have practical applications into aquaculture. It will also further enhance our understanding on the reproduction and fertility control of other vertebrates, including human.

卵母细胞（卵子）在卵巢内的发育和成熟是复杂的事件，需要来自大脑、垂体和卵巢的信号分子的协调。我们一直使用斑马鱼作为实验模型来研究卵巢来源的信号分子，特别是转化生长因子-β（TGF-β）家族和microRNA（miRNA）的成员，如何在卵巢内发挥调节作用，以控制卵子的发育和成熟。在接下来的五年里，我们将扩展这些研究，以研究Nodal和几种特定的miRNAs的作用：Aim 1。Nodal在斑马鱼卵巢中的生理作用和信号机制Nodal是已知在胚胎发育中起关键作用的TGF-β家族的成员。然而，其在卵巢生理学中的作用尚不清楚。在斑马鱼中存在三个Nodal相关基因（ndr 1、ndr 2和ndr 3）。我们正在使用遗传工具来删除这些基因单独或组合，并将使用这些敲除系来研究这些基因如何参与调节雌性斑马鱼的繁殖。具体而言，我们将比较野生型鱼和ndr突变体之间类固醇激素的产生、卵母细胞成熟、排卵、产卵和胚胎产生。我们还将通过研究Nodal诱导的各种信号通路来确定Nodal如何在斑马鱼卵巢中发挥调节作用。 目标2. microRNAs在斑马鱼卵泡生长和卵母细胞成熟中的作用miRNAs是一类在基因调控中起重要作用的非编码小分子RNAs。miRNAs在卵巢发育和卵母细胞成熟中的作用在很大程度上是未知的。我们最近鉴定了许多在IIIa期（对成熟诱导激素无反应的小卵黄发生卵泡）和IIIb期（成熟能力强的大卵黄发生卵泡）卵泡细胞之间差异表达的miRNA。我们将选择在IIIb期卵泡细胞中减少最强烈的四种miRNAs，以研究它们在卵巢中的功能和作用模式。我们将开发敲除细胞系来研究这些miRNAs缺失对卵泡发育、卵母细胞成熟、排卵、产卵和胚胎生产的影响。这些miRNA被预测为靶向Nodal受体和参与卵母细胞成熟的关键激素的信号传导组分。我们将描述这些miRNAs的靶基因，以了解这些miRNAs如何在生殖中发挥作用。 这项研究计划将为Nodal和miRNAs如何参与鱼类卵巢生理的调节提供新的见解，并可能在水产养殖中有实际应用。这亦会进一步加深我们对其他脊椎动物，包括人类的生殖和生育控制的认识。