Sperm equatorial segment protein 1, SPESP1, is required for fully fertile sperm in mouse
Sperm equatorial segment protein 1, SPESP1, is required for fully fertile sperm in mouse
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DOI：
10.1242/jcs.067363
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发表时间：
2010-05-01
影响因子：
4
通讯作者：
Okabe, Masaru
中科院分区：
文献类型：
--
作者：
Fujihara, Yoshitaka;Murakami, Masao;Okabe, Masaru
哺乳动物的受精是一个多步骤的过程，在精子和卵子的质膜融合时达到高潮。人们普遍认为顶体反应精子的赤道段在受精过程中开始与卵质膜融合是重要的。已知有各种蛋白质只分布在精子的赤道部分。这些蛋白的作用必须澄清，以了解膜融合过程。我们制作了一个缺乏SPESP1（精子赤道段蛋白1）的小鼠品系，并分析了精子的受精能力。Spesp1（+/-）和Spesp1（-/-）雄鼠的幼崽平均数量显著低于野生型雄鼠。在这些小鼠系中，迁移到输卵管中的精子较少，受精卵较少。与野生型精子相比，Spesp1（+/-）和Spesp1（-/-）精子的融合能力较低。Spesp1的破坏被证明会导致各种精子蛋白的异常分布。此外，扫描电镜显示，spesp1缺陷小鼠的赤道段区域通常形成顶体鞘的膜在顶体反应后消失。结果表明，SPESP1是产生完全“融合能力”精子所必需的。
Mammalian fertilization is a multistep process that culminates in the fusion of the sperm and egg plasma membrane. It is widely accepted that the equatorial segment of the acrosome-reacted sperm is important in initiating fusion with the egg plasma membrane during fertilization. There are various proteins known to be distributed only in the equatorial segment of sperm. The role of these proteins must be clarified to understand the membrane fusion process. We produced a mouse line that lacked SPESP1 (sperm equatorial segment protein 1) and analyzed the fertilizing ability of the sperm. The average number of pups that were fathered by Spesp1(+/-) and Spesp1(-/-) males was significantly lower than that of wild-type fathers. In these mouse lines, fewer sperm were found to migrate into oviducts and fewer eggs were fertilized. The Spesp1(+/-) and Spesp1(-/-) sperm showed a lower fusing ability compared with the wildtype sperm. The disruption of Spesp1 was shown to cause an aberrant distribution of various sperm proteins. Moreover, scanning electron microscopy revealed that the membrane in the equatorial segment area, which usually forms an acrosomal sheath, disappears after acrosome reaction in Spesp1-deficient mice. It was demonstrated that SPESP1 is necessary to produce the fully 'fusion competent' sperm.