Three neural tubes in mouse embryos with mutations in the T-box gene Tbx6
Three neural tubes in mouse embryos with mutations in the T-box gene Tbx6
复制标题
DOI：
10.1038/35624
复制
发表时间：
1998-02-12
期刊：
影响因子：
64.8
通讯作者：
Papaioannou, VE
中科院分区：
文献类型：
--
作者：
Chapman, DL;Papaioannou, VE
节体是脊椎动物胚胎的分节中胚层单位，是成年骨骼肌、骨和软骨的前体(1)。在胚胎发生过程中，体体祖细胞通过原始条纹进入，向外侧移动到近轴位置（沿体轴），并分裂成上皮体体(2)。关于这种近轴中胚层组织是如何被指定的知之甚少（1,2）。我们之前描述过一个小鼠T-box基因Tbx6（文献3），它编码一种假定的dna结合蛋白（4,5）。Tbx6在体细胞前体细胞中的胚胎表达模式表明该基因可能参与了近轴中胚层的形成(3)。我们现在报告了Tbx6突变的产生，该突变深刻地影响了近轴中胚层的分化。突变胚胎的颈部区域形成不规则的体体，而更多的后轴旁组织不形成体体，而是沿着神经通路分化，形成轴神经管侧面的神经管样结构。这些近轴管显示神经管的背/腹侧模式，并具有分化的运动神经元。这些结果表明，在原肠胚形成过程中，细胞需要Tbx6来选择中胚层和神经元分化途径；Tbx6对于后近轴中胚层的形成至关重要，在缺乏Tbx6的情况下，注定形成后胚层的细胞会沿着神经元通路分化。
Somites, segmented mesodermal units of the vertebrate embryo, are the precursors of adult skeletal muscle, bone and cartilage(1). During embryogenesis, somite progenitor cells ingress through the primitive streak, move laterally to a paraxial position (alongside the body axis) and segment into epithelial somites(2). Little is known about how this paraxial mesoderm tissue is specified(1,2). We have previously described a mouse T-box gene, Tbx6 (ref. 3), which codes for a putative DNA-binding protein(4,5). The embryonic pattern of expression of Tbx6 in somite precursor cells suggests that this gene may be involved in the specification of paraxial mesoderm(3). We now report the creation of a mutation in Tbx6 that profoundly affects the differentiation of paraxial mesoderm. Irregular somites form in the neck region of mutant embryos, whereas more posterior paraxial tissue does not form somites but instead differentiates along a neural pathway, forming neural-tube-like structures that flank the axial neural tube. These paraxial tubes show dorsal/ventral patterning that is characteristic of the neural tube, and have differentiated motor neurons, These results indicate that Tbx6 is needed for cells to choose between a mesodermal and a neuronal differentiation pathway during gastrulation; Tbx6 is essential for the specification of posterior paraxial mesoderm, and in its absence cells destined to form posterior somites differentiate along a neuronal pathway.