The immunoglobulin superfamily protein Izumo is required for sperm to fuse with eggs
The immunoglobulin superfamily protein Izumo is required for sperm to fuse with eggs
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DOI：
10.1038/nature03362
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发表时间：
2005-03-10
期刊：
影响因子：
64.8
通讯作者：
Okabe, M
中科院分区：
文献类型：
--
作者：
Inoue, N;Ikawa, M;Okabe, M
精子和卵子代表了构成人体的60万亿个细胞，它们相遇，相互识别，融合形成新一代的生命。参与这一重要的膜融合事件——受精——的因素已经被寻找了很长时间(1)。最近，发现卵子膜上的CD9对融合至关重要（2-4），但与精子相关的融合因子仍然未知。本研究通过融合抑制单克隆抗体(5)和基因克隆，鉴定了一种小鼠精子融合相关抗原，并证明该抗原是一种新的免疫球蛋白超家族蛋白。我们将这种基因命名为出云基因，并培育出一种基因被破坏的小鼠品系。Izumo（-/-）小鼠健康，但雄性不育。他们产生了与透明带结合并穿透的正常精子，但不能与卵子融合。人类精子也含有出云病毒，添加了抗人类出云病毒的抗体后，精子无法与无带的仓鼠卵融合。
Representing the 60 trillion cells that build a human body, a sperm and an egg meet, recognize each other, and fuse to form a new generation of life. The factors involved in this important membrane fusion event, fertilization, have been sought for a long time(1). Recently, CD9 on the egg membrane was found to be essential for fusion(2-4), but sperm-related fusion factors remain unknown. Here, by using a fusion-inhibiting monoclonal antibody(5) and gene cloning, we identify a mouse sperm fusion-related antigen and show that the antigen is a novel immunoglobulin superfamily protein. We have termed the gene Izumo and produced a gene-disrupted mouse line. Izumo(-/-) mice were healthy but males were sterile. They produced normal-looking sperm that bound to and penetrated the zona pellucida but were incapable of fusing with eggs. Human sperm also contain Izumo and addition of the antibody against human Izumo left the sperm unable to fuse with zona-free hamster eggs.