Carey F J, Linney E A, Pedersen R A
Laboratory of Radiobiology and Environmental Health, University of California, San Francisco 94143-0750, USA.
Dev Genet. 1995;17(1):29-37. doi: 10.1002/dvg.1020170105.
The embryonic ectoderm, or epiblast, is the source of the three primary germ layers that form during gastrulation in the mouse embryo. Previous studies have investigated the fate of epiblast cells in early gastrulation stages using clonal analysis of cell lineage and in late gastrulation stages using transplantation of labeled grafts. In this study, we studied the fate of late gastrulation stage epiblast using a clonal analysis based on a retroviral vector encoding the Escherichia coli lacZ gene. We found that by reducing the volume of viral suspension injected into each embryo, it was possible to achieve single infectious events. Our analysis of 20 embryos singly infected at the late streak stage and 21 at the head fold stage revealed clonal descendants in only a single germ layer in each embryo. These results indicate that allocation of epiblast progenitors to a single germ layer fate has occurred by late gastrulation in mouse embryos.
胚胎外胚层，即上胚层，是小鼠胚胎原肠胚形成过程中形成的三个主要胚层的来源。先前的研究使用细胞谱系克隆分析研究了原肠胚形成早期阶段上胚层细胞的命运，并使用标记移植物移植研究了原肠胚形成后期阶段的情况。在本研究中，我们使用基于编码大肠杆菌lacZ基因的逆转录病毒载体的克隆分析，研究了原肠胚形成后期阶段上胚层的命运。我们发现，通过减少注入每个胚胎的病毒悬液体积，可以实现单个感染事件。我们对20个在晚期条纹阶段单独感染的胚胎和21个在头褶阶段单独感染的胚胎进行分析，发现每个胚胎中只有一个胚层有克隆后代。这些结果表明，在小鼠胚胎原肠胚形成后期，上胚层祖细胞已被分配到单个胚层命运。
