Possible involvement of CD81 in acrosome reaction of sperm in mice
Possible involvement of CD81 in acrosome reaction of sperm in mice
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DOI：
10.1002/mrd.20709
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发表时间：
2008-01
影响因子：
2.5
通讯作者：
Maya Tanigawa;Kiyoko T. Miyamoto;Satoshi Kobayashi;Masahiro Sato;H. Akutsu;M. Okabe;E. Mekada;K. Sakakibara;M. Miyado;A. Umezawa;K. Miyado
中科院分区：
文献类型：
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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 CD81与CD9在氨基酸序列上具有较高的同源性。众所周知，CD9参与精子-卵子融合，CD81也参与膜融合事件。然而，CD81和CD9在膜融合中的作用尚不清楚。在这里，我们报告了小鼠CD81基因的破坏导致雌性小鼠繁殖力的下降，并且CD81−/−卵子与精子的融合能力受损。此外，我们还发现，当CD81−/−卵子与精子孵育时，部分穿透到CD81−/−卵子卵黄周间隙的精子尚未发生顶体反应，提示CD81−/−卵子的融合性受损可能部分是由于精子顶体反应失败所致。此外，我们还发现CD81在卵母细胞周围的颗粒细胞中高表达。我们的观察结果表明，在精子与卵子直接相互作用之前，精子与卵子周围体细胞上的CD81存在相互作用。我们的结果可能为阐明精子-卵子融合所需的顶体反应的细胞机制提供新的线索。摩尔。是Reprod。戴夫。75：150-155,2008.©2007 Wiley-Liss Inc.
Tetraspanin CD81 is closely homologous in amino acid sequence with CD9. CD9 is well known to be involved in sperm–egg fusion, and CD81 has also been reported to be involved in membrane fusion events. However, the function of CD81 as well as that of CD9 in membrane fusion remains unclear. Here, we report that disruption of the mouse CD81 gene led to a reduction in the fecundity of female mice, and CD81−/− eggs had impaired ability to fuse with sperm. Furthermore, we demonstrated that when CD81−/− eggs were incubated with sperm, some of the sperm that penetrated into the perivitelline space of CD81−/− eggs had not yet undergone the acrosome reaction, indicating that the impaired fusibility of CD81−/− eggs may be in part caused by failure of the acrosome reaction of sperm. In addition, we showed that CD81 was highly expressed in granulosa cells, somatic cells that surround oocytes. Our observations suggest that there is an interaction between sperm and CD81 on somatic cells surrounding eggs before the direct interaction of sperm and eggs. Our results may provide new clues for clarifying the cellular mechanism of the acrosome reaction, which is required for sperm–egg fusion. Mol. Reprod. Dev. 75: 150–155, 2008. © 2007 Wiley‐Liss, Inc.