Acrosin is essential for sperm penetration through the zona pellucida in hamsters
Acrosin is essential for sperm penetration through the zona pellucida in hamsters
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DOI：
10.1073/pnas.1917595117
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发表时间：
2020-02-04
影响因子：
11.1
通讯作者：
Ogura, Atsuo
中科院分区：
文献类型：
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作者：
Hirose, Michiko;Honda, Arata;Ogura, Atsuo
在自然受精过程中，哺乳动物精子必须通过透明带才能到达卵母细胞的质膜。据推测，这一步骤涉及精子顶体酶对顶体小带的部分溶解，但没有明确的证据支持这一观点。在这里，我们提出的证据表明，顶体酶，一种顶体丝氨酸蛋白酶，在精子穿透透明带的过程中发挥着重要作用。我们利用体内转基因CRISPR/Cas9系统获得了顶体酶基因敲除(KO)仓鼠。纯合子突变的男性完全不育。顶体素-KO精子爬上女性生殖道，到达输卵管壶腹部的排卵卵母细胞，但从未使其受精。体外受精(IVF)实验表明，突变精子附着在透明带上，但未能穿透。IVF前摘除透明带后，所有卵母细胞均受精。这表明，在仓鼠体内，顶体酶在使受精精子穿透小带的过程中发挥着不可或缺的作用。这项研究还表明，KO仓鼠系统将是一个有用的模型，以确定新的基因功能或分析人类和动物的疾病，因为它的技术便利和重复性。
During natural fertilization, mammalian spermatozoa must pass through the zona pellucida before reaching the plasma membrane of the oocyte. It is assumed that this step involves partial lysis of the zona by sperm acrosomal enzymes, but there has been no unequivocal evidence to support this view. Here we present evidence that acrosin, an acrosomal serine protease, plays an essential role in sperm penetration of the zona. We generated acrosin-knockout (KO) hamsters, using an in vivo transfection CRISPR/Cas9 system. Homozygous mutant males were completely sterile. Acrosin-KO spermatozoa ascended the female genital tract and reached ovulated oocytes in the oviduct ampulla, but never fertilized them. In vitro fertilization (IVF) experiments revealed that mutant spermatozoa attached to the zona, but failed to penetrate it. When the zona pellucida was removed before IVF, all oocytes were fertilized. This indicates that in hamsters, acrosin plays an indispensable role in allowing fertilizing spermatozoa to penetrate the zona. This study also suggests that the KO hamster system would be a useful model for identifying new gene functions or analyzing human and animal disorders because of its technical facility and reproducibility.