Molecular Mechanism of sperm-egg membrane fusion in fertilization

受精过程中精卵膜融合的分子机制

• 批准号: 16390480
• 负责人: MIYADO Kenji
• 金额: $ 8.96万
• 依托单位: National Center for Child Health and Development
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390480/
• 关键词: Fertilization; Membrane Fusion; CD9; CD81; Microvilli; Tubulin; Tetraspanin; Imaging

Fertilization is an essential process that naturally produces a cell capable for developing into a new individual. However, a molecular mechanism that underlying membrane interaction of sperm and egg still remains a mystery in mammals. CD9, a tetraspan-membrane protein (tetraspanin), expressed in a wide variety of cells, is reported to function in many cellular events. CD9 associates with other tetraspanins and some kinds of membrane proteins to form complexes at the plasma membrane. In fertilization, CD9 is required for sperm-egg fusion, and also implicated in other fusion events. When inseminated, eggs from CD9-/-females bound sperm normally, but were greatly impaired in fusion with sperm, but not developmental processes. Since CD9 can associate with integrins, models of fertilization have posited that CD9 acts in association with alpha6betal in fusion. However, analyses of deficient eggs have sublated that integrins are essential for sperm-egg fusion. A new model in which CD9 acts by itself, or interacts with egg protein(s) other than integrins, to function in sperm-egg fusion, was proposed. CD9 was exclusively localized to microvilli, not concentrated of actin-filaments. Electron microscopy also revealed that CD9-/-eggs had a severe defect in microvilli formation. When a vector, expressing EGFP- tagged CD9 under oocyte-specific promoter, was transferred into CD9-/-females, both gametes fusion and microvilli formation were restored. Microvilli, visualized by EGFP-CD9, was vitally monitored and defined to function in gametes fusion. These results indicate that CD9 is a key element for the formation of microvilli required for sperm-egg fusion.

受精是自然产生能够发育成新个体的细胞的重要过程。然而，哺乳动物精卵膜相互作用的分子机制仍然是一个谜。据报道，CD 9是一种在多种细胞中表达的四跨膜蛋白（四跨膜蛋白），在许多细胞事件中起作用。CD 9与其他四跨膜蛋白和某些膜蛋白在质膜上形成复合物。在受精过程中，CD 9是精卵融合所必需的，也涉及其他融合事件。当受精时，来自CD 9-/-雌性的卵子正常结合精子，但在与精子融合时受到极大损害，但发育过程没有。由于CD 9可以与整联蛋白结合，受精模型已经假定CD 9在融合中与α 6 β 1结合起作用。然而，对缺陷卵子的分析表明，整合素对精卵融合是必不可少的。提出了一种新的模型，其中CD 9本身起作用，或与卵蛋白而不是整合素相互作用，以在精卵融合中起作用。CD 9只定位于微绒毛，而不是集中的肌动蛋白丝。电子显微镜还显示，CD 9-/-鸡蛋有一个严重的缺陷，微绒毛的形成。当将在卵母细胞特异性启动子下表达EGFP标记的CD 9的载体转移到CD 9-/-雌性中时，配子融合和微绒毛形成均恢复。通过EGFP-CD 9可视化的微绒毛被重要地监测并定义为在配子融合中起作用。这些结果表明，CD 9是精卵融合所需的微绒毛形成的关键因素。

项目成果

A Novel Marker for Purkinje Cells, KIAA0864 Protein. An Analysis Based on a Monoclonal Antibody HFB-16 in Developing Human Cerebellum

浦肯野细胞的新型标记物，KIAA0864 蛋白。

• 发表时间: 2005
• 期刊: The Journal of Histochemistry ＆ Cytochemistry. 53(4)
• 作者: Nakamura Y;et al.
• 通讯作者: et al.

Menstrual blood-derived cells confer human dystrophin expression in the murine model of Duchenne muscular dystrophy via cell fusion and myogenic transdifferentiation

• DOI: 10.1091/mbc.e06-09-0872
• 发表时间: 2007-05-01
• 期刊: MOLECULAR BIOLOGY OF THE CELL
• 影响因子: 3.3
• 作者: Cui, Chang-Hao;Uyama, Taro;Umezawa, Akihiro
• 通讯作者: Umezawa, Akihiro

Possible involvement of CD81 in acrosome reaction of sperm in mice

• DOI: 10.1002/mrd.20709
• 发表时间: 2008-01
• 期刊: Molecular Reproduction and Development
• 影响因子: 2.5
• 作者: Maya Tanigawa;Kiyoko T. Miyamoto;Satoshi Kobayashi;Masahiro Sato;H. Akutsu;M. Okabe;E. Mekada;K. Sakakibara;M. Miyado;A. Umezawa;K. Miyado

Tetraspanin protein CD9 is a novel paranodal component regulating paranodal junctional formation

• DOI: 10.1523/jneurosci.1484-03.2004
• 发表时间: 2004-01-07
• 期刊: JOURNAL OF NEUROSCIENCE
• 影响因子: 5.3
• 作者: Ishibashi, T;Ding, L;Baba, H
• 通讯作者: Baba, H

Possible role of mouse poly(A) polymerase mGLD-2 during oocyte maturation

• DOI: 10.1016/j.ydbio.2005.10.017
• 发表时间: 2006-01-01
• 期刊: DEVELOPMENTAL BIOLOGY
• 影响因子: 2.7
• 作者: Nakanishi, T;Kubota, H;Baba, T
• 通讯作者: Baba, T