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的数据，这些数据暗示碳水化合物和氨基酸是减数分裂调节中的重要参与者，尽管尚未描述作用的具体机制。 本文提出的实验将解决与三种势能底物的参与有关的特定问题 - 丙酮酸，葡萄糖和谷氨酰胺 - 卵母细胞的成熟。 首先，将分析与减数分裂成熟有关，对卵母细胞和卵母细胞 - 肿瘤细胞复合物的消耗进行分析。 要测试的假设是，在减数分裂成熟的不同阶段存在不同的能量需求，特别是，丙酮酸的需求随着卵母细胞发展到中期II而增加。 其次，将评估氨基酸在减数分裂成熟中的作用，并特别强调谷氨酰胺，利用代谢分析和HPLC分析氨基酸动力学。 数据将提供有关积云颗粒细胞与卵母细胞之间相互作用的见解以及细胞细胞偶联途径在谷氨酰胺作用上的重要性。 第三，我们将研究丙酮酸是颗粒状颗粒细胞分泌的阳性旁分泌因子并作用于卵母细胞以触发减数分裂恢复的可能性。 这一系列的实验将测试积云细胞和卵泡半剖面在共培养的裸卵形卵母细胞中诱导减数分裂成熟的能力。 然后，我们将将这种反应与积累在培养基中的丙酮酸水平联系起来。 这些结果将对生育和避孕具有重要意义，因为每个结果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。 它们还可能有助于防止或最小化错误的减数分裂控制，从而导致非整倍性及其灾难性后果。 此外，这些研究将使体外系统的发展有益于减数分裂停滞或减数分裂成熟是所需的终点。