OOCYTE CORTICAL MATURATION AND GRANULE ACTIVATION

卵母细胞皮质成熟和颗粒激活

• 批准号: 2673566
• 负责人: THOMAS W DUCIBELLA
• 金额: $ 20.48万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2673566
• 关键词: aneuploidy; calcium flux; carbohydrate receptor; cell cell interaction; egg /ovum; egg proteins; exocytosis; female; fertilization; granule; inositol phosphates; laboratory mouse; sperm; tissue /cell culture

In humans and other mammals, 1-5% of fertilized eggs become triploid, abort, and die. Human triploidy is primarily due to fertilization by more than one sperm and is usually prevented by the release of egg cortical granules (CGs) whose contents biochemically modify the egg's zona pellucida. In a mouse model, the long-term objectives are to identify: (Aim 1) an important cause of triploidy that originates from a failure of CG release and (Aim 2) egg proteins responsible for the prevention of triploidy. The failure of CG release, associated with incomplete cytoplasmic maturation in mice and humans, involves second messengers and their targets: inositol trisphosphate (IP3), calcium (Ca), and Ca-dependent proteins. Aims: 1) Development of Ca signaling for CG release: Does the ability to undergo CG exocytosis develop from increases in Ca release (hypothesis A) or an increased response to Ca (hypothesis B)? Prior to ovulation, is CG exocytosis failure due to insufficient elevation of Ca, a lack of sensitivity to Ca, and/or improper amount, localization, or phosphorylation of IP3 receptor isoforms (channels for intracellular Ca release)? 2) Biochemical characterization of individual (egg CG) proteins released at fertilization. Testing the hypothesis that one or more proteins are responsible for the zona protein (ZP3)-mediated block to polyspermy, characterized by reductions in sperm binding and in the acrosome reaction. Technical Methods: High resolution fluorescence microscopy and computerized image analysis of CGs, Ca imaging, electrophoresis, ultrasensitive chemiluminescence protein detection, and bioassays. Significance: Aim 1) Identification of a signaling deficiency would provide an important 'marker' for oocyte cytoplasmic maturation and a more detailed scientific explanation for the origin of abnormal triploid abortuses. Determination of a quantitative relationship between egg Ca and CG release (& cell cycle resumption) will advance our knowledge of the role of Ca in fertilization. Aim 2) The biochemical identification of the egg protein(s) modifying ZP3 is an important step in elucidating the molecular mechanism responsible for the mammalian block to polyspermy. This research may lead to a new non-invasive egg activation assay of released CG proteins (for optimizing or monitoring animal and human in vitro fertilization).

在人类和其他哺乳动物中，1-5% 的受精卵变成 三倍体， 中止，然后死亡。 人类三倍体主要是由于受精 经过 超过一个精子，通常通过释放卵子来阻止 皮质颗粒（CG），其内容物可以生化改变 鸡蛋的 透明带。 在小鼠模型中，长期目标是 识别：（目标 1）三倍体起源的重要原因 从一个 CG 释放失败和（目标 2）卵蛋白导致 预防三倍体。 CG释放失败，相关 和 小鼠和人类的不完全细胞质成熟涉及 第二 信使及其目标：三磷酸肌醇 (IP3)、钙 (钙), 和钙依赖蛋白。 目标： 1) CG 释放的 Ca 信号传导的发展：是否有能力 因 Ca 释放增加而发生 CG 胞吐作用 （假设A） 或者对 Ca 的反应增加（假设 B）？ 排卵前， 是CG 由于 Ca 升高不足、缺乏 对 Ca 的敏感性，和/或不当的量、定位或 IP3 受体亚型的磷酸化（通道 细胞内钙 发布）？ 2) 个体（鸡蛋CG）蛋白质的生化特征 释放 在受精时。 检验一种或多种蛋白质的假设 是 负责透明带蛋白 (ZP3) 介导的阻断 多精受精, 其特点是精子结合和顶体减少 反应。 技术方法：高分辨率荧光显微镜和 CG 计算机图像分析、Ca 成像、电泳、 超灵敏化学发光蛋白质检测和生物测定。 意义：目标 1) 识别信号缺陷将 为卵母细胞胞质成熟提供重要的“标记” 一个 对异常起源更详细的科学解释 三倍体 流产。 确定之间的数量关系 蛋钙 CG 发布（和细胞周期恢复）将增进我们的知识 的 Ca 在受精中的作用。 目标 2) 生化 鉴别 鸡蛋蛋白修饰 ZP3 是实现这一目标的重要一步。 阐明 负责哺乳动物阻断的分子机制 多精受精。 这项研究可能会产生一种新的非侵入性鸡蛋 激活 释放的 CG 蛋白测定（用于优化或监测动物 和 人类体外受精）。