Gastrulation events in the prestreak pig embryo:: Ultrastructure and cell markers
Gastrulation events in the prestreak pig embryo:: Ultrastructure and cell markers
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DOI：
10.1002/gene.10244
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发表时间：
2004-01-01
期刊：
影响因子：
1.5
通讯作者：
Fléchon, B
中科院分区：
文献类型：
--
作者：
Fléchon, JE;Degrouard, J;Fléchon, B
应用电镜和分子标记技术，对猪条纹前期胚胎外胚层和中胚层细胞的上皮细胞和间充质细胞表型进行了研究。在此期间，胚盘保持平坦或略凸，同时变成椭圆形或梨形。表达波形蛋白的间充质细胞存在于胚盘和下面的内脏内胚层之间，在原始条纹（或凹槽）明显之前。间充质的迁移似乎发生在位于表达Brachyury的梨形胚盘尖端的大量静止细胞的侧向和后部方向;这些细胞被认为是原条的前体和/或形成小鼠早期原肠胚组织者（EGO）的等效物。TEC-1（或SSEA-1）表位的细胞，最常用于表征多能细胞的标志物，最初随机分布在胚胎外胚层，然后被发现定位在一个前新月体，其中可能包含外胚层和神经外胚层的前体细胞。由于仅在前新月体中发现有丝分裂像，因此建议至少有一些增殖细胞向EGO迁移。虽然细胞角蛋白在胚胎外胚层细胞中几乎检测不到，但波形蛋白的表达被认为与这些细胞的迁移能力有关。这些结果表明，原肠胚形成的早期步骤，胚外中胚层的迁移，发生在prestreak阶段，在此期间，胚胎光盘成为极化。（C）2003 Wiley-Liss，Inc.
The epithelial versus mesenchymal phenotypes of embryonic ectoderm and mesoderm cells of the prestreak stage pig embryos were examined by electron microscopy and molecular marker analysis. During this period the embryonic disc remained flat or slightly convex while becoming oval or pyriform in shape. Mesenchyme cells expressing vimentin were present between the embryonic disc and the underlying visceral endoderm before a primitive streak (or groove) was apparent. The migration of mesenchyme appeared to occur in lateral and posterior directions from a mass of quiescent cells located in the pointed end of the pyriform embryonic disc that expressed Brachyury; these cells are proposed to be the precursors of the primitive streak and/or form the equivalent of the mouse early gastrula organizer (EGO). Cells with the TEC-1 (or SSEA-1) epitope, the marker most frequently used to characterize pluripotent cells, were initially distributed randomly in the embryonic ectoderm and then were found to localize in an anterior crescent which may contain the precursor cells of ectoderm and neurectoderm. As mitotic figures were found only in the anterior crescent, it is proposed that at least some of these proliferating cells migrate toward the EGO. While cytokeratins were barely detectable in the embryonic ectoderm cells, vimentin expression was supposed to be associated with the migratory capacity of these cells. These findings indicate that the early step of gastrulation, migration of extraembryonic mesoderm, occurs at a prestreak stage during which the embryonic disc becomes polarized. genesis (C) 2003 Wiley-Liss, Inc.