Komorowski Sebastian, Baranowska Barbara, Maleszewski Marek
Department of Embryology, Institute of Zoology, Warsaw University, Warsaw, Poland.
Zygote. 2006 May;14(2):119-23. doi: 10.1017/S0967199405003497.
CD9 is a member of the tetraspanin superfamily proteins and is the only protein on the mouse oocyte which is known to be indispensable in sperm-egg fusion. Here, using indirect immunofluorescence we show that CD9 appears on the oolemma during the early stages of the growth of the oocyte, when it measures 13-22 microm in diameter. When the oocyte reaches a diameter of 17-22 microm, the density of CD9 in its oolemma is similar to the density of this protein in the cell membrane of the fully grown secondary oocyte. The appearance of CD9 in growing oocytes correlates with the previously reported time of the acquisition of fusibility between the spermatozoon and the egg. Accordingly we propose that during oogenesis the development of the ability of the oolemma to fuse with sperm may be regulated by synthesis of CD9 by the oocyte.
CD9是四跨膜蛋白超家族的成员，是小鼠卵母细胞上已知在精卵融合中不可或缺的唯一蛋白质。在此，我们通过间接免疫荧光显示，CD9在卵母细胞生长早期出现在卵膜上，此时卵母细胞直径为13 - 22微米。当卵母细胞直径达到17 - 22微米时，其卵膜中CD9的密度与完全成熟的次级卵母细胞膜中该蛋白质的密度相似。CD9在生长中的卵母细胞中的出现与先前报道的精子与卵子之间获得融合能力的时间相关。因此，我们提出在卵子发生过程中，卵膜与精子融合能力的发展可能受卵母细胞合成CD9的调控。
