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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745846
• 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.

卵巢内卵母细胞（卵）的发育和成熟是一个复杂的过程，需要来自大脑、垂体和卵巢的信号分子的协调。我们一直以斑马鱼为实验模型，研究卵巢来源的信号分子，特别是转化生长因子- β (tgf - β)家族成员和microRNAs （miRNAs）如何在卵巢内发挥调节作用，控制卵子的发育和成熟。在接下来的五年中，我们将扩展这些研究，以研究Nodal和几种特定mirna的作用：Nodal是tgf - β家族的一员，在胚胎发育中起关键作用。然而，其在卵巢生理中的作用尚不清楚。斑马鱼有三个节点相关基因（ndr1、ndr2和ndr3）。我们正在使用遗传工具来单独或组合地删除这些基因，并将使用这些基因敲除系来研究这些基因如何参与调节雌性斑马鱼的生殖。具体来说，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microRNAs是一种小的非编码rna，在基因调控中起重要作用。mirna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。我们最近发现了许多mirna在IIIa期（对成熟诱导激素无反应的小卵黄细胞）和IIIb期（成熟能力强的大卵黄细胞）卵泡细胞之间差异表达。我们将选择四个在IIIb期卵泡细胞中下降最强烈的mirna来研究它们在卵巢中的功能和作用模式。我们将开发基因敲除系来研究这些mirna缺失对卵泡发育、卵母细胞成熟、排卵、产卵和胚胎产生的影响。据预测，这些mirna靶向参与卵母细胞成熟的关键激素的节点受体和信号成分。我们将描述这些mirna的靶基因，以了解这些mirna如何在生殖中发挥作用。该研究项目将为Nodal和mirna如何参与鱼类卵巢生理调节提供新的见解，并可能在水产养殖中有实际应用。这也将进一步加深我们对包括人类在内的其他脊椎动物的生殖和生育控制的认识。