PDF(Pubmed)
Abstract：
Pax3/7 factors play numerous roles in the development of the dorsal nervous system of vertebrates. From specifying neural crest at the neural plate borders, to regulating neural tube closure and patterning of the resulting neural tube. However, it is unclear which of these roles are conserved in non-vertebrate chordates. Here we investigate the expression and function of Pax3/7 in the model tunicate Ciona. Pax3/7 is expressed in neural plate border cells during neurulation, and in central nervous system progenitors shortly after neural tube closure. We find that separate cis-regulatory elements control the expression in these two distinct lineages. Using CRISPR/Cas9-mediated mutagenesis, we knocked out Pax3/7 in F0 embryos specifically in these two separate territories. Pax3/7 knockout in the neural plate borders resulted in neural tube closure defects, suggesting an ancient role for Pax3/7 in this chordate-specific process. Furthermore, knocking out Pax3/7 in the neural impaired Motor Ganglion neuron specification, confirming a conserved role for this gene in patterning the neural tube as well. Taken together, these results suggests that key functions of Pax3/7 in neural tube development are evolutionarily ancient, dating back at least to the last common ancestor of vertebrates and tunicates.
摘要：
Pax3/7因子在脊椎动物背神经系统的发育中起着许多作用。通过在神经板边界指定神经峰，调节神经管的闭合和形成神经管的图案。然而,目前尚不清楚这些角色中哪些在非脊椎动物脊索动物中是保守的。在这里，我们研究了Pax3/7在Ciona模型中的表达和功能。Pax3/7在神经板边界细胞中表达，以及神经管闭合后不久的中枢神经系统祖细胞。我们发现单独的顺式调节元件控制这两个不同谱系中的表达。使用CRISPR/Cas9介导的诱变，我们在F0胚胎中敲除Pax3/7，特别是在这两个独立的区域。Pax3/7敲除神经板边界导致神经管闭合缺陷，这表明Pax3/7在这种脊索特异性过程中的古老作用。此外，在神经受损的运动神经节神经元规范中敲除Pax3/7，证实了该基因在设计神经管中的保守作用。一起来看,这些结果表明，Pax3/7在神经管发育中的关键功能在进化上是古老的，至少可以追溯到脊椎动物和被膜动物的最后一个共同祖先。
