Department of Zoology, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto, Japan.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192, Japan.
Dev Biol. 2020 May 15;461(2):160-171. doi: 10.1016/j.ydbio.2020.02.007. Epub 2020 Feb 12.
In amniotes, unlike primary neurulation in the anterior body, secondary neurulation (SN) proceeds along with axial elongation by the mesenchymal-to-epithelial transition of SN precursors in the tail bud. It has been under debate whether the SN is generated by neuromesodermal common progenitor cells (NMPs) or neural restricted lineage. Our direct cell labeling and serial transplantations identify uni-fated (neural) precursors in the early tail bud. The uni-fated SN precursor territory is further divided into two subpopulations, neural-differentiating and self-renewing cells, which are regulated by high- and low levels of Sox2, respectively. Unexpectedly, uni-fated SN precursors change their fate at later stages to produce both SN and mesoderm. Thus, chicken embryos adopt a previously unappreciated prolonged phase with uni-fated SN stem cells in the early tail bud, which is absent or very limited in mouse embryos.
在羊膜动物中，与前部身体的初级神经胚形成不同，次级神经胚形成（SN）通过尾部芽生的 SN 前体细胞的间充质到上皮的转变，伴随着轴向伸长而进行。SN 是由神经中胚层共同祖细胞（NMPs）还是神经限制谱系产生一直存在争议。我们的直接细胞标记和连续移植鉴定了早期尾芽中的单能（神经）前体细胞。单能 SN 前体细胞区域进一步分为两个亚群，即神经分化和自我更新细胞，它们分别受 Sox2 的高和低水平调节。出乎意料的是，单能 SN 前体细胞在后期改变其命运，产生 SN 和中胚层。因此，鸡胚胎在早期尾芽中采用了以前未被认识的延长的单能 SN 干细胞阶段，而在小鼠胚胎中则不存在或非常有限。
