Godin I E, Garcia-Porrero J A, Coutinho A, Dieterlen-Lièvre F, Marcos M A
Institut d'Embryologie Cellulaire et Moléculaire du CNRS, Nogent-sur-Marne, France.
Nature. 1993 Jul 1;364(6432):67-70. doi: 10.1038/364067a0.
Definitive erythropoiesis in birds originates from stem cells that emerge in the splanchnopleural mesoderm near the embryonic aorta. The yolk sac is still generally held to be the unique provider of haematopoietic stem cells during mammalian ontogeny, although there may be an alternative intraembryonic source of stem cells in the mouse fetus. Here we search for a possible non-yolk-sac source of stem cells by grafting intraembryonic splanchnopleura from 10- to 18-somite mouse embryos into adult immunodeficient SCID mice. We find significant amounts of donor-derived serum IgM, normal numbers of IgM-secreting plasma cells, and the B1a (IgM(a)brightB220dullCD5+) cell subset to be fully reconstituted by donor progenitors 3 to 6 months after engraftment. The haematogenic capacity revealed in our experiments is present in a previously unrecognized site, the earliest described in the embryo, 12 hours before fetal liver colonization.
鸟类的确定性红细胞生成起源于胚胎主动脉附近脏壁中胚层出现的干细胞。尽管在小鼠胎儿中可能存在胚胎内干细胞的替代来源，但卵黄囊在哺乳动物个体发育过程中仍通常被认为是造血干细胞的唯一提供者。在这里，我们通过将10至18体节小鼠胚胎的胚胎内脏壁移植到成年免疫缺陷SCID小鼠中，寻找干细胞可能的非卵黄囊来源。我们发现，移植后3至6个月，供体来源的血清IgM含量显著，分泌IgM的浆细胞数量正常，并且供体祖细胞能完全重建B1a（IgM⁺brightB220⁻dullCD5⁺）细胞亚群。我们实验中揭示的造血能力存在于一个先前未被认识的部位，这是胚胎中最早被描述的部位，在胎儿肝脏定植前12小时。
