机械阻断神经管的闭合影响爪蟾神经管辐射状切入及神经嵴细胞定向迁移(英文)

神经管闭合缺陷 (NTDs)是一种严重的先天畸形疾病，在新生儿中有千分之一的发病率。神经管融合前后，多种组织参与形态发生运动。神经管一经融合，神经嵴细胞就会向背侧中线方向产生单极突出并向此方向迁移形成神经管的顶部。与此同时，神经管从腹侧开始发生辐射状切入以实现单层化。在此，我们在非洲爪蟾的移植体中机械阻断神经管的闭合以检测其细胞运动及随后的图式形成。结果显示神经管闭合缺陷的移植体不能形成单层化的神经管，并且神经嵴细胞滞留在侧面区域不能向背侧中线迁移，而对神经前体标记基因的检测显示神经管的背腹图式形成并未受到影响。以上结果表明神经管的融合对于辐射状切入和神经嵴细胞向背侧中线方向的迁移过程是必需的，而对于神经管的沿背腹轴方向的图式形成是非必需的。

Physical Blocking Neural Tube Closure Affects Radial Intercalation and Neural Crest Midline-directed Migration in Xenopus Dorsal Explants

Neural tube defects (NTDs) are severe congenital malformation diseases, which occur in 1 out of 1000 births in human. In Xenopus, several tissue movements are involved in the neural tube closure process. Immediately after the neural tube fusion, the neural crest cells get monopolar protrusion toward dorsal midline and migrate to form the roof of the neural tube. At the same time, radial intercalation takes place from the ventral neural tube and forces it to be single-layered. Here, we physically block the neural tube closure to test the cell movements and the following patterning in Xenopus laevis explants. The results show that the single-layered neural tube fails to form and the neural crest cells remain at the lateral regions in the explants with NTDs. However, the patterning of the neural tube is not affected as indicated by the normal expression of the preneural genes. These results indicate a requirement of the neural tube fusion for the radial intercalation and the dorsal midline directed neural crest migration, but not for the dorsal-ventral patterning of the neural tube.