FORMATION OF CYTOSKELETAL ELEMENTS DURING MOUSE EMBRYOGENESIS .2. EPITHELIAL DIFFERENTIATION AND INTERMEDIATE-SIZED FILAMENTS IN EARLY POSTIMPLANTATION EMBRYOS
FORMATION OF CYTOSKELETAL ELEMENTS DURING MOUSE EMBRYOGENESIS .2. EPITHELIAL DIFFERENTIATION AND INTERMEDIATE-SIZED FILAMENTS IN EARLY POSTIMPLANTATION EMBRYOS
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DOI：
10.1111/j.1432-0436.1981.tb01177.x
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发表时间：
1981-01-01
期刊：
影响因子：
2.9
通讯作者：
ILLMENSEE, K
中科院分区：
文献类型：
--
作者：
JACKSON, BW;GRUND, C;ILLMENSEE, K
用电子显微镜、免疫荧光显微镜和~(35)S-蛋氨酸标记的细胞骨架蛋白双向凝胶电泳法研究了植入后早期胚胎细胞骨架元素的组成。由胚胎外胚层和近(内脏)内胚层形成的特征性上皮具有发达的连接复合体和各种分化的膜结构。近端内皮细胞的几个顶端分化，如刷状边状微绒毛、内吞迷路和核上空泡，类似于新生哺乳动物回肠上皮细胞的组织结构。两种胚胎上皮均显示典型的桥粒和附着的中等大小的角蛋白类型的细丝。在第6天和第7天胚胎的任何细胞中都没有检测到其他类型的中等大小的细丝，如波形蛋白和结蛋白细丝，但在第8天晚些时候，在形成中胚层的某些细胞中可以看到波形蛋白类型的细丝。凝胶电泳法还显示，在胚胎外和胚胎组织中6-8天合成的主要细胞骨架蛋白与植入前胚泡的特征相似，并包括一种与成年啮齿动物某些内脏器官中描述的细胞角蛋白A相对应的主要多肽。通过相同的技术，在第8天晚些时候首次发现了另一种细胞骨架蛋白Vimentin的合成。移植后早期胚胎发育，直到中胚层的形成，其特征是在胚胎外胚层和近端内胚层中，仅存在含有桥粒-细胞角蛋白细丝复合体的分化上皮细胞；其他类型的中等大小的细丝尚未表达。
Organization of cytoskeletal elements in early postimplantation emryos up to day 8 of gestation was examined employing EM, immunofluorescence microscopy and 2-dimensional gel electrophoresis of cytoskeletal proteins labeled by incorporation of 35S-methionine. The characteristic epithelia formed by the embryonic ectoderm and proximal (visceral) endoderm present well-developed junctional complexes and various differentiated membrane structures. Several apical differentiations of the proximal endodermal cells, such as brush border-like microvilli, the endocytotic labyrinthum and the supranuclear vacuoles, resemble the organization of epithelial cells of the ileum of neonatal mammals. Both embryonic epithelia show typical desmosomes and attached intermediate-sized filaments of the cytokeratin type. Other types of intermediate-sized filaments, such as vimentin and desmin filaments, have not been detected in any of the cells of embryos of days 6 and 7, but filaments of the vimentin type can be seen, by immunofluorescence microscopy, late in day 8 in certain cells located in the forming mesoderm. Gel electrophoresis also revealed that the major cytoskeletal proteins synthesized during days 6-8 in extraembryonic and embryonic tissue are similar to those characteristic of preimplantation blastocysts and include a major polypeptide corresponding to cytokeratin A described in some internal organs of adult rodents. By the same techniques, synthesis of another cytoskeletal protein, vimentin, was first found late in day 8. Early postimplantation embryonic development, up to mesoderm formation, is characterized by the exclusive presence, in embryonic ectoderm and proximal endoderm, of differentiated epithelial cells containing desmosome-cytokeratin filament complexes; other types of intermediate-sized filaments are not yet expressed.