Nodal regulates neural tube formation in the Ciona intestinalis embryo
Nodal regulates neural tube formation in the Ciona intestinalis embryo
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DOI：
10.1007/s00427-007-0168-x
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发表时间：
2007-08-01
影响因子：
2.4
通讯作者：
Fujiwara, Shigeki
中科院分区：
文献类型：
--
作者：
Mita, Kaoru;Fujiwara, Shigeki
在原脊索动物海鞘中，一个左撇子的直系同源基因Ci-lefty的过度表达导致了神经管关闭的失败。躯体向背侧弯曲，前后伸长受到抑制。在用SB 43 1542（Nodal受体的抑制剂）处理的胚胎中观察到类似的表型，表明Ci-Lefty拮抗Nodal信号传导，如在其他后口动物物种中报道的。Ci-nodal的过表达也导致类似的表型，表明Nodal信号传导的正确数量和/或空间限制对于神经管的形成是重要的。除了已知的Ci-Nodal靶基因之外，Zic（Ci-ZicL）和cdx（Ci-cdx）的直向同源物也被Ci-Nodal激活。显性负性Ci-cdx的表达引起神经管形成的缺陷，类似于用SB 431542或过表达Ci-lefty处理所获得的缺陷。Ci-Nodal、Ci-ZicL和Ci-Cdx组成的调控级联可能在玻璃海鞘胚胎神经管形成中起重要作用。
Overexpression of a lefty orthologue, Ci-lefty, caused a failure of neural tube closure in the protochordate ascidian Ciona intestinalis. The body bent dorsally, and anterior-posterior elongation was inhibited. A similar phenotype was observed in embryos treated with SB43 1542, an inhibitor of Nodal receptors, suggesting that Ci-Lefty antagonized Nodal signaling as reported in other deuterostome species. Overexpression of Ci-nodal also resulted in a similar phenotype, suggesting that a correct quantity and/or a spatial restriction of Nodal signaling are important for the neural tube to form. In addition to known Ci-Nodal target genes, orthologues of Zic (Ci-ZicL) and cdx (Ci-cdx) were activated by Ci-Nodal. Expression of a dominant negative Ci-cdx caused defects in neural tube formation similar to those obtained on treatment with SB431542 or overexpression of Ci-lefty. A regulatory cascade composed of Ci-Nodal, Ci-ZicL, and Ci-Cdx may play an important role in neural tube fori-nation in the Ciona embryo.