Lehtonen E, Reima I
Differentiation. 1986;32(2):125-34. doi: 10.1111/j.1432-0436.1986.tb00564.x.
It has been proposed that vinculin is a microfilament bundle-membrane linking cytoskeletal protein. We used double-fluorescence microscopy to study the distribution of vinculin and F-actin in mouse oocytes and preimplantation embryos. In oocytes and in the cells of cleavage- and blastocyst-stage embryos, vinculin exhibited a diffuse cytoplasmic distribution and was concentrated in a submembranous layer. The presence of vinculin in oocytes was confirmed by immunoblotting. In oocytes, a distinct concentration of actin was observed above the second metaphase spindle. During the 8-cell stage, compacting blastomeres exhibited partial polarization of cortical vinculin and actin toward their outward-facing surfaces. In precompaction-stage blastomeres, the submembranous layer of vinculin contained a ring-like concentration in the most peripheral region of each intercellular contact area. During later development, the amount of vinculin localized in the areas of intercellular contacts became modified. In embryos ranging from the compacted 8-cell stage to the mid-morula stage, the vinculin-specific fluorescence was only intense in some intercellular contacts, being indistinct in most contact areas. In late morulae, the flattened outer cells increasingly exhibited concentration of vinculin in contact areas. In contrast, actin-specific fluorescence was clearly evident in most intercellular contacts throughout the morula stage. At the early blastocyst stage, all contacts of the trophectoderm (TE) cells again regularly exhibited concentration of both components. At the late blastocyst stage, the staining pattern changed once again: the contact-associated concentration of vinculin-specific fluorescence was not observed in polar TE cells, while remaining clear in mural TE cells. In blastocyst outgrowths, TE cells displayed typical vinculin plaques at the peripheries of the cells. The continuous changes in the distribution of vinculin and actin suggest that these components are involved in the control of cellular relationships during early development. Immunoelectron microscopy and experiments using cytochalasin were performed in an attempt to relate the distribution of vinculin to the ultrastructural features of embryo cells.
有人提出纽蛋白是一种连接微丝束与细胞膜的细胞骨架蛋白。我们使用双荧光显微镜研究纽蛋白和F-肌动蛋白在小鼠卵母细胞和植入前胚胎中的分布。在卵母细胞以及卵裂期和囊胚期胚胎的细胞中，纽蛋白呈现出弥漫性的细胞质分布，并集中在亚膜层。通过免疫印迹证实了卵母细胞中存在纽蛋白。在卵母细胞中，在第二次减数分裂中期纺锤体上方观察到明显的肌动蛋白聚集。在8细胞期，紧密化的卵裂球表现出皮质纽蛋白和肌动蛋白朝着其外向表面的部分极化。在预紧密化阶段的卵裂球中，纽蛋白的亚膜层在每个细胞间接触区域的最外围区域含有环状聚集。在后期发育过程中，定位在细胞间接触区域的纽蛋白数量发生了变化。在从紧密化的8细胞期到桑葚胚中期的胚胎中，纽蛋白特异性荧光仅在一些细胞间接触中强烈，在大多数接触区域不明显。在晚期桑葚胚中，扁平的外层细胞在接触区域越来越多地表现出纽蛋白的聚集。相比之下，在整个桑葚胚期的大多数细胞间接触中，肌动蛋白特异性荧光都清晰可见。在早期囊胚期，滋养外胚层（TE）细胞的所有接触再次规律性地表现出这两种成分的聚集。在晚期囊胚期，染色模式再次改变：在极性TE细胞中未观察到与接触相关的纽蛋白特异性荧光聚集，而在壁TE细胞中仍然清晰。在囊胚外植体中，TE细胞在细胞周边显示出典型的纽蛋白斑。纽蛋白和肌动蛋白分布的持续变化表明这些成分参与了早期发育过程中细胞关系的控制。进行了免疫电子显微镜和使用细胞松弛素的实验，试图将纽蛋白的分布与胚胎细胞的超微结构特征联系起来。
