卵母细胞健康成熟是进行鱼类繁育和养殖的基础。黄体生成素（LH）是调控卵母细胞成熟的主要因子，但LH信号如何传入卵母细胞的分子机制尚未清楚，也是目前鱼类生殖生理学的研究热点。我们初步的研究提示：瘦素（leptin b）是介导LH信号诱导斜带石斑鱼卵母细胞成熟的潜在因子。在此基础上，本项目将从以下五方面深入探讨leptin信号调控斜带石斑鱼卵母细胞成熟的分子机制：（1）LH如何激活leptin b的表达？（2）leptin b作用于滤泡细胞或卵母细胞调控卵母细胞成熟？（3）leptin b通过何种分子机制调控卵母细胞成熟？（4）leptin b是否为LH诱导的卵母细胞成熟所必须？（5）leptin b在促卵巢成熟中的应用？通过以上的研究，将帮助我们了解leptin信号在石斑鱼卵母细胞成熟过程中的作用；也有助于我们深入了解石斑鱼类卵母细胞成熟的分子调控机制。

One of the major objectives of the fish aquaculture industry is the production of a large number of viable eggs with high survival. Fundamental information on fish oocyte maturation and its application to artificial induction of sexual maturation are needed to produce good quality eggs. It has been widely accepted that oocyte maturation is regulated by luteinizing hormone (LH). However, the molecular mechanisms of how LH signal is transmitted into the oocyte remains to be studied. Our preliminary data suggest that leptin b plays an important role in mediating the action of LH signaling in the regulation of oocyte maturation in orange-spotted grouper. In order to reveal the mechanisms of leptin b in the regulation of oocyte maturation in grouper, in this project, we propose to (ⅰ) investigate which signal pathway of LH regulates the expression of leptin b in the follicles, (ⅱ) investigate whether the leptin b induce oocyte maturation via acting on follicular cell layer or oocyte, (ⅲ) elucidate the molecular mechanisms of leptin b in inducing oocyte maturation, (ⅳ) investigate whether leptin b is indispensable for mediating LH action on oocyte maturation, (ⅴ) evaluate the potential application of leptin b in inducing the ovarian development and maturation. Our study will uncover the functions and mechanisms of leptin signaling in the process of oocyte maturation in orange-spotted grouper, and also provide valuable information for elucidating the regulatory mechanisms of oocyte maturation in grouper species.