Watanabe Hiroshi, Kuhn Anne, Fushiki Manami, Agata Kiyokazu, Özbek Suat, Fujisawa Toshitaka, Holstein Thomas W
Department of Molecular Evolution and Genomics, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 329, 69120 Heidelberg, Germany.
1] Department of Molecular Evolution and Genomics, Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 329, 69120 Heidelberg, Germany [2] Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan.
Nat Commun. 2014 Dec 23;5:5536. doi: 10.1038/ncomms6536.
Animal evolution is closely linked to the emergence of the nervous system. At present it is unknown how the basic mechanisms of neural induction and formation of central nervous systems evolved. We addressed this question in Nematostella vectensis, a member of cnidarians, the ancient sister group of bilaterians. We found that β-catenin signalling is crucial for the early induction of the embryonic nervous system. β-Catenin activity at the blastopore induces specific neurogenic genes required for development of the oral nervous system. β-Catenin signalling induces also Bmp signalling, which, at later larval stages, becomes indispensible for the maintenance and asymmetric patterning of the oral nervous system along the primary and secondary (directive) axes. We hypothesize that the consecutive and functionally linked involvement of β-catenin and Bmp signalling in the formation of the cnidarian oral nervous system reflects an ancestral mechanism that evolved before the cnidarian/bilaterian split.
动物进化与神经系统的出现密切相关。目前尚不清楚神经诱导和中枢神经系统形成的基本机制是如何进化的。我们在刺胞动物门的成员星状海葵中解决了这个问题，刺胞动物门是两侧对称动物的古老姐妹类群。我们发现β-连环蛋白信号传导对于胚胎神经系统的早期诱导至关重要。胚孔处的β-连环蛋白活性诱导口腔神经系统发育所需的特定神经源性基因。β-连环蛋白信号传导还诱导Bmp信号传导，在幼虫后期，Bmp信号传导对于口腔神经系统沿初级和次级（定向）轴的维持和不对称模式形成变得不可或缺。我们假设β-连环蛋白和Bmp信号传导在刺胞动物口腔神经系统形成过程中的连续且功能相关的参与反映了一种在刺胞动物/两侧对称动物分化之前就已进化的祖先机制。
