Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, 102-0076, Japan.
Sci Rep. 2017 Aug 21;7(1):8955. doi: 10.1038/s41598-017-08305-2.
The somatopleure is the amniotic primordium in amniote development, but its boundary to the embryonic body at early embryonic stages and the fate of cells constituting this structure are not well characterized. It also remains unclear how cells behave during the demarcation between intra- and extra-embryonic tissues. Here we identify cellular alignments, which indicate two streams towards the sites of dorsal amniotic closure and ventral thoracic wall formation. A subpopulation of mesodermal cells moving ventrally from the somatopleural region adjacent to the base of the head fold enter the body of the embryo and distribute to the thoracic wall, pharyngeal arches and heart. These cells are induced to differentiate into vascular endothelial cells and cardiomyocytes possibly by FGF and BMP signaling, respectively. These results indicate that the somatopleure acting as the amniotic primordium also serves as a source of embryonic cells, which may contribute to cardiovascular development.
体壁层是羊膜动物胚胎发育中的羊膜原基，但在早期胚胎阶段，其与胚胎体的边界以及构成该结构的细胞命运尚不清楚。此外，细胞在胚胎内组织和胚胎外组织之间的分界处如何行为也不清楚。在这里，我们鉴定了细胞排列，这表明有两个流朝向背侧羊膜闭合和腹侧胸壁形成的部位。从头部褶皱基部附近的体壁层区域向腹侧移动的一部分中胚层细胞进入胚胎体，并分布到胸壁、咽弓和心脏。这些细胞可能分别通过 FGF 和 BMP 信号诱导分化为血管内皮细胞和心肌细胞。这些结果表明，作为羊膜原基的体壁层也充当胚胎细胞的来源，这可能有助于心血管发育。
