Evans J P, Page B D, Kay B K
Department of Biology, University of North Carolina, Chapel Hill 27599-3280.
Dev Biol. 1990 Feb;137(2):403-13. doi: 10.1016/0012-1606(90)90264-j.
We have investigated the expression and distribution of talin and vinculin in the oocytes, eggs, and embryos of Xenopus laevis. Antibodies to the previously characterized avian proteins stain several different Xenopus cell types identically by immunofluorescence: adhesion plaques of cultured kidney (A6) cells, the cell peripheries of oviduct cells, and the postsynaptic neuromuscular junctions of tadpole tail muscle fibers. These antibodies also identify cognate proteins of the appropriate sizes on immunoblots of A6 cell and oviduct lysates. Using these antibodies on ovarian tissue, we find talin to be highly localized at the cortices of oocytes and vinculin to be in the oocyte cytoplasm and absent from the oocyte cortex. In the cells of the ovarian layers that surround the oocytes, talin and vinculin can be detected as soluble and cytoskeletal components. Vinculin is first detectable as a cytoskeletal component in eggs, appearing some time during or between oocyte maturation and oviposition. During early embryo development, talin and vinculin are colocalized in the cortex of cleavage furrows and blastomeres. Thus, Xenopus oocytes and eggs display different distributions of talin and vinculin. The change from unlinked localization to colocalization appears to be developmentally regulated, occurring during the transition from oocyte to egg.
我们研究了踝蛋白（talin）和纽蛋白（vinculin）在非洲爪蟾（Xenopus laevis）卵母细胞、卵子和胚胎中的表达及分布情况。针对先前已鉴定的禽类蛋白的抗体，通过免疫荧光法对几种不同的非洲爪蟾细胞类型进行染色，结果显示染色情况相同：培养的肾（A6）细胞的黏着斑、输卵管细胞的细胞周边以及蝌蚪尾部肌纤维的突触后神经肌肉接头。这些抗体在A6细胞和输卵管裂解物的免疫印迹上也能识别出大小合适的同源蛋白。利用这些抗体对卵巢组织进行检测，我们发现踝蛋白高度定位于卵母细胞的皮质，而纽蛋白存在于卵母细胞的细胞质中，卵母细胞皮质中则没有。在围绕卵母细胞的卵巢层细胞中，踝蛋白和纽蛋白可被检测为可溶性成分和细胞骨架成分。纽蛋白最早在卵子中作为细胞骨架成分被检测到，出现在卵母细胞成熟期间或成熟与产卵之间的某个时间段。在胚胎发育早期，踝蛋白和纽蛋白共定位于卵裂沟和卵裂球的皮质中。因此，非洲爪蟾的卵母细胞和卵子中踝蛋白和纽蛋白呈现出不同的分布。从非关联定位到共定位的变化似乎受到发育调控，发生在从卵母细胞到卵子的转变过程中。
