MEIOTIC REGULATION IN MAMMALIAN OOCYTES

哺乳动物卵母细胞的减数分裂调节

• 批准号: 6159193
• 负责人: STEPHEN M DOWNS
• 金额: $ 13.38万
• 依托单位: MARQUETTE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6159193
• 关键词: aminoacid metabolism; bioenergetics; cell growth regulation; egg /ovum; glucose; glutamine; granulosa cell; high performance liquid chromatography; laboratory mouse; meiosis; paracrine; pyruvates; reproductive development; tissue /cell culture

A major goal of my research program is to identify molecules and metabolic pathways that participate in the control of oocyte maturation in mammals. We have generated considerable data implicating carbohydrates and amino acids as important participants in meiotic regulation, although specific mechanisms of action have not yet been delineated. The experiments proposed herein will address specific questions relating to the involvement of three potential energy substrates--pyruvate, glucose and glutamine--in oocyte maturation. First, an analysis will be made of pyruvate and glucose consumption by oocytes and oocyte-cumulus cell complexes as it relates to meiotic maturation. The hypothesis to be tested is that different energy requirements exist at different stages of meiotic maturation, specifically, that pyruvate requirements increase as the oocyte progresses to metaphase II. Second, the role(s) of amino acids in meiotic maturation will be assessed, with special emphasis on glutamine, utilizing metabolic assays and HPLC analysis of amino acid dynamics. The data will provide insights on the interaction between cumulus granulosa cells and the oocyte and the importance of the cell-cell coupling pathway on glutamine action. Third, we will examine the possibility that pyruvate is a positive paracrine factor that is secreted by cumulus granulosa cells and acts on the oocyte to trigger meiotic resumption. This series of experiments will test the ability of cumulus cells and follicle hemisections to induce meiotic maturation in cocultured denuded and cumulus cell-enclosed oocytes. We will then relate this response to levels of pyruvate that accumulate in the culture medium. These results will have important implications for both fertility and contraception, since each is affected by the ability of the oocyte to successfully initiate and complete meiotic maturation. They may also help in preventing or minimizing erroneous meiotic control that can give rise to aneuploidy and its disastrous consequences. Furthermore, these studies will benefit the development of in vitro systems where either meiotic arrest or completion of meiotic maturation is the desired endpoint.

我的研究计划的一个主要目标是确定参与控制哺乳动物卵母细胞成熟的分子和代谢途径。 我们已经生成了大量数据，表明碳水化合物和氨基酸是减数分裂调节的重要参与者，尽管尚未描述具体的作用机制。 本文提出的实验将解决与卵母细胞成熟中三种势能底物——丙酮酸、葡萄糖和谷氨酰胺——相关的具体问题。 首先，将分析卵母细胞和卵母细胞-卵丘细胞复合体的丙酮酸和葡萄糖消耗，因为它与减数分裂成熟有关。 要测试的假设是减数分裂成熟的不同阶段存在不同的能量需求，具体来说，随着卵母细胞进入中期 II，丙酮酸需求增加。 其次，将利用代谢测定和氨基酸动力学的 HPLC 分析来评估氨基酸在减数分裂成熟中的作用，特别是谷氨酰胺。 这些数据将提供有关颗粒卵丘细胞和卵母细胞之间相互作用以及细胞间偶联途径对谷氨酰胺作用的重要性的见解。 第三，我们将检查丙酮酸是否是一种正性旁分泌因子，由卵丘颗粒细胞分泌并作用于卵母细胞以触发减数分裂恢复。 这一系列实验将测试卵丘细胞和卵泡半切在共培养的裸露卵母细胞和卵丘细胞封闭卵母细胞中诱导减数分裂成熟的能力。 然后我们将这种反应与培养基中积累的丙酮酸水平联系起来。 这些结果将对生育和避孕产生重要影响，因为两者都受到卵母细胞成功启动和完成减数分裂成熟的能力的影响。 它们还可能有助于预防或最大程度地减少错误的减数分裂控制，这种控制可能导致非整倍性及其灾难性后果。 此外，这些研究将有利于体外系统的开发，其中减数分裂停滞或减数分裂成熟的完成是所需的终点。