Linfor J, Berger T
Department of Animal Science, University of California, Davis, CA 95616, USA.
J Reprod Fertil. 2000 Sep;120(1):65-72.
Integrin molecules are cell adhesion molecules that are thought to be involved in sperm-oocyte interaction in rodents and humans. The objective of this study was to evaluate whether integrin molecules were present on the surface of pig oocytes, consistent with involvement in sperm-oocyte interaction in this species. Immunocytochemistry and confocal microscopy were used to evaluate the presence of beta1, and alpha1, alpha2, alpha3, alpha4, alpha5, alpha6 and alphav integrin subunits on the plasma membrane of pig oocytes. The beta1 and alphav integrin subunits were present consistently at the surface of pig oocytes; however, the remaining alpha integrin subunits evaluated were not routinely detected. The antibodies to the beta1 and alphav integrin subunits recognized appropriately sized protein bands on western blots of partially purified oocyte plasma membrane. These two antibodies also recognized oocyte plasma membrane protein isolated from a sperm plasma membrane affinity column. Sperm plasma membrane proteins of 137 and 93 kDa appeared to be the ligands for the beta1 integrin subunit as revealed by a western sandwich blot. Antibody to an extracellular domain of the beta1 integrin subunit reduced pig sperm-oocyte binding (P < 0.05), also indicating an assisting role for a beta1 oocyte integrin subunit in sperm-oocyte interaction in pigs. These results are consistent with an alphavbeta1 pig oocyte integrin interacting with a ligand on the sperm plasma membrane during fertilization.
整合素分子是细胞粘附分子，被认为参与啮齿动物和人类的精子-卵母细胞相互作用。本研究的目的是评估整合素分子是否存在于猪卵母细胞表面，这与该物种精子-卵母细胞相互作用有关。免疫细胞化学和共聚焦显微镜用于评估猪卵母细胞质膜上β1以及α1、α2、α3、α4、α5、α6和αv整合素亚基的存在情况。β1和αv整合素亚基始终存在于猪卵母细胞表面；然而，所评估的其余α整合素亚基未被常规检测到。针对β1和αv整合素亚基的抗体在部分纯化的卵母细胞质膜的蛋白质印迹上识别出大小合适的蛋白条带。这两种抗体还识别从精子质膜亲和柱分离的卵母细胞质膜蛋白。蛋白质印迹法显示，137 kDa和93 kDa的精子质膜蛋白似乎是β1整合素亚基的配体。针对β1整合素亚基细胞外结构域的抗体减少了猪精子与卵母细胞的结合（P < 0.05），这也表明β1卵母细胞整合素亚基在猪精子-卵母细胞相互作用中起辅助作用。这些结果与受精过程中猪卵母细胞αvβ1整合素与精子质膜上的配体相互作用一致。
