MAMMALIAN SPERM SURFACE ORGANIZATION AND FUNCTION

哺乳动物精子表面的组织和功能

• 批准号: 2696569
• 负责人: Diana G Myles
• 金额: $ 24.72万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2003-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2696569
• 关键词: acrosome; cell adhesion; cell adhesion molecules; egg /ovum; enzyme substrate; fertilization; genetically modified animals; guinea pigs; immunofluorescence technique; integrins; laboratory mouse; membrane fusion; membrane proteins; metalloendopeptidases; phagocytosis; protein purification; purinergic receptor; sperm; surface property; tissue /cell culture

The overall goal of this proposal is to understand each step in the process of sperm-egg plasma membrane adhesion and fusion. The first step is the contact between the tip of the acrosome-reacted sperm (the inner acrosomal membrane, IAM) and the egg plasma membrane. The second step is the adhesion between these sperm surface equatorial/posterior head region and the egg plasm membrane. Additional steps may follow adhesion and lead to membrane fusion. Previous work implicated two sperm surface proteins, fertilin and cyritestin, as acting in the equatorial/posterior head region binding step. Mutant (knockout) mice lacking fertilin were produced. The homologous, mutant males were infertile. Aim 1 proposes to use these mice to define the precise role of fertilin in gamete membrane binding, fusion and egg activation. A cyritestin gene knockout is also being generated. Aim 2 proposes to use male mice lacking cyritestin to determine cyritestin function in gamete membrane binding, fusion and egg activation. Aim 3 focuses on the first step in gamete membrane interaction, i.e. contact of the sperm IAM with the egg surface. It will be tested if this contact promotes later adhesion steps and/or the phagocytosis-like process that takes the IAM into the egg cytoplasm. Aim 4 proposes to study steps that may occur after sperm bind, but before they fuse. It will be tested if there is a metalloprotease or a surface ATP receptor that must act before fusion occurs. Aim 5 addresses the question of what molecules on the egg plasma membrane participate in interactions with the sperm that lead to fusion. It will determine if the egg surface integrin, alpha-6-beta-1, an adhesion partner for either fertilin or cyritestin. It will also propose to us a unique approach with a tissue culture cell line that fuses with mouse sperm to identify another egg protein that promotes membrane fusion. Understanding the molecular basis of the gamete fusion process may allow new developments in assisted reproduction. Furthermore, the identified, functional gamete proteins are potential targets for novel contraceptive methods based on pharmacological and immunological approaches.

该提议的总体目标是了解 精子 - 卵形质膜粘附和融合的过程。第一步 是Adrosome反应精子的尖端之间的接触（内部 Arosomal膜，IAM）和卵质膜。 第二步 是这些精子表面赤道/后头之间的粘附 区域和卵质膜。 其他步骤可能遵循附着力 并导致膜融合。 以前的工作暗示了两个精子表面 蛋白质，受精蛋白和甲状腺素，作用于赤道/后部 头部区域结合步骤。 缺乏肥料的突变体（敲除）小鼠是 生产。 同源的突变雄性不育。 AIM 1提出 使用这些小鼠来定义肥料在配子中的确切作用 膜结合，融合和卵子激活。 Cyritestin基因敲除 也正在生成。 AIM 2建议使用缺少雄性小鼠 塞里特蛋白确定配子膜结合中的西里蛋白功能， 融合和鸡蛋激活。 AIM 3专注于配子的第一步 膜相互作用，即精子IAM与鸡蛋的接触 表面。 如果此触点促进以后的附着力，它将进行测试 步骤和/或将IAM带入的类似吞噬作用的过程 卵细胞质。 AIM 4建议研究精子后可能发生的步骤 绑定，但在它们融合之前。 如果有一个 金属蛋白酶或表面ATP受体必须在融合前起作用 发生。 AIM 5解决了鸡蛋上什么分子的问题 质膜与导致的精子进行互动 融合。 它将确定卵表面整合素是否α-6-β-1， 受精蛋白或甲状腺素的粘附伴侣。 它也会 向我们提出一种独特的方法，该方法具有组织培养细胞系 与小鼠精子融合以识别另一种促进的卵子蛋白 膜融合。 了解配子融合的分子基础 过程可能允许辅助生殖的新发展。 此外，已鉴定的功能配子蛋白是潜在的 基于药理和 免疫学方法。