Department of Anatomy and Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan; JST, ERATO, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
JST, ERATO, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan; Research Center for Animal Life Science, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu, Shiga 520-2192, Japan.
Dev Cell. 2016 Oct 24;39(2):169-185. doi: 10.1016/j.devcel.2016.09.007. Epub 2016 Oct 6.
The germ cell lineage ensures reproduction and heredity. The mechanism for germ cell specification in primates, including humans, has remained unknown. In primates, upon implantation the pluripotent epiblast segregates the amnion, an extra-embryonic membrane eventually ensheathing an embryo, and thereafter initiates gastrulation to generate three germ layers. Here, we show that in cynomolgus monkeys, the SOX17/TFAP2C/BLIMP1-positive primordial germ cells (cyPGCs) originate from the dorsal amnion at embryonic day 11 (E11) prior to gastrulation. cyPGCs appear to migrate down the amnion and, through proliferation and recruitment from the posterior amnion, expand in number around the posterior yolk sac by E17. Remarkably, the amnion itself expresses BMP4 and WNT3A, cytokines potentially critical for cyPGC specification, and responds primarily to them. Moreover, human PGC-like cells in vitro exhibit a transcriptome similar to cyPGCs just after specification. Our study identifies the origin of PGCs and a unique function of the nascent amnion in primates.
生殖细胞系确保了繁殖和遗传。包括人类在内的灵长类动物生殖细胞的特化机制仍然未知。在灵长类动物中，多能上胚层在植入后会分离出羊膜，这是一种最终包裹胚胎的胚胎外膜，随后启动原肠胚形成，产生三个胚层。在这里，我们发现在食蟹猴中，SOX17/TFAP2C/BLIMP1 阳性原始生殖细胞（cyPGC）起源于原肠胚形成前的胚龄 11 天（E11）的背侧羊膜。cyPGC 似乎沿着羊膜向下迁移，并通过增殖和从前侧羊膜募集，在 E17 时围绕后蛋黄囊扩张数量。值得注意的是，羊膜本身表达 BMP4 和 WNT3A，这两种细胞因子可能对 cyPGC 的特化至关重要，并主要对其做出反应。此外，体外的人类 PGC 样细胞在特化后不久就表现出与 cyPGC 相似的转录组。我们的研究确定了 PGC 的起源以及新生羊膜在灵长类动物中的独特功能。
