Sperm from the calmegin-deficient mouse have normal abilities for binding and fusion to the egg plasma membrane
Sperm from the calmegin-deficient mouse have normal abilities for binding and fusion to the egg plasma membrane
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DOI：
10.1006/dbio.2002.0803
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发表时间：
2002-10-15
影响因子：
2.7
通讯作者：
Okabe, M
中科院分区：
文献类型：
--
作者：
Yamagata, K;Nakanishi, T;Okabe, M
Calmegin是一种假定的睾丸特异性分子伴侣，是精子α / β异二聚化和精子表面出现β所需的分子伴侣。钙蛋白缺乏的小鼠几乎完全不育。不育的原因最初被认为是精子/透明带（ZP）和精子/卵质膜（EPM）结合能力受损，以及精子向输卵管的上升，表型与受精β缺乏动物的精子相似。我们开发了一种新的方法，在这种方法中，使用压电驱动的微机械臂制备卵子，使其表面没有任何可检测到的ZP3。利用这些卵和精子顶体中含有绿色荧光蛋白，可以区分顶体完整和顶体反应的精子，重新检查钙蛋白缺乏精子的结合和融合能力。在这些条件下，顶体反应的精子保留了与EPM结合和融合的能力。钙蛋白（-/-）小鼠精子中EPM结合的减少显然是由于钙蛋白（+/-）小鼠的大量顶体完整精子与酸性Tyrode’s溶液制备的EPM上残留的ZP残留物人工结合所致。因此，钙蛋白缺失动物的精子缺陷不是在精子与epm结合的水平上，而是可能涉及精子与zp结合和/或精子转运到输卵管。由于钙蛋白缺乏小鼠中缺乏β -受精素，这些结果也表明β -受精素在精子- epm相互作用中的作用需要重新评估。(C) 2002 Elsevier Science （USA）。
Calmegin is a putative testis-specific molecular chaperone required for the heterodimerization of fertilin alpha/beta and the appearance of fertilin beta on the sperm surface. Calmegin-deficient mice are almost completely sterile. The cause of the sterility initially was considered to be impaired abilities in sperm/zona pellucida (ZP) and sperm/egg plasma membrane (EPM) binding, and in the ascension of sperm to the oviduct, phenotypes similar to those seen in sperm from fertilin beta-deficient animals. We have developed a new method in which eggs were prepared without any detectable ZP3 on their surfaces by using a piezo-driven micromanipulator. Using these eggs and sperm containing the green fluorescent protein in their acrosomes, which can distinguish acrosome-intact from acrosome-reacted sperm, the binding and fusing abilities of calmegin-deficient sperm were reexamined. Under these conditions, acrosome-reacted sperm retained their ability to bind to and fuse with the EPM. The reduction in EPM binding of sperm from the calmegin(-/-) animals was apparently due to the artifactual binding of large numbers of acrosome-intact sperm from calmegin(+/-) mice to ZP remnants remaining on the EPM prepared with acidic Tyrode's solution. Thus, the sperm defect in calmegin-null animals is not at the level of sperm-EPM binding but rather may involve either sperm-ZP binding and/or sperm transit to the oviduct. Because fertilin beta is absent from calmegin-deficient mice, these results also suggest that the role of fertilin beta in sperm-EPM interaction needs to be reevaluated. (C) 2002 Elsevier Science (USA).