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.

中文翻译：

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在鸡尾芽的二次培养过程中，Sox2调控的神经命运自我更新细胞。

在羊膜动物中，与前体中的初级神经节不同，次级神经节（SN）随着SN前体在尾芽中的间质向上皮转变而伴随着轴向伸长而进行。SN是由神经中胚层共同祖细胞（NMP）还是神经限制性谱系产生的，一直存在争议。我们的直接细胞标记和连续移植可识别早期尾芽中的单缘（神经）前体。单功能SN前体区域进一步分为两个亚群，即神经分化细胞和自我更新细胞，它们分别受高和低水平的Sox2调控。出乎意料的是，单功能SN前体会在以后的阶段改变命运，从而同时产生SN和中胚层。从而，