Cell movements of the deep layer of non-neural ectoderm underlie complete neural tube closure in Xenopus
Cell movements of the deep layer of non-neural ectoderm underlie complete neural tube closure in Xenopus
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DOI：
10.1242/dev.073239
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发表时间：
2012-04-15
期刊：
影响因子：
4.6
通讯作者：
Ueno, Naoto
中科院分区：
文献类型：
--
作者：
Morita, Hitoshi;Kajiura-Kobayashi, Hiroko;Ueno, Naoto
在发育中的脊椎动物中，神经管由一片神经外胚层通过复杂的细胞运动和形态发生形成。神经外胚层细胞的会聚伸展运动和顶端收缩以及顶端-基底伸长被认为对于神经管闭合（NTC）过程至关重要。此外，众所周知，非神经外胚层在这一过程中也发挥着至关重要的作用，因为在小鸡和蝾螈中，如果没有这种组织，神经管就无法闭合。然而，其在 NTC 中发挥作用的细胞和分子机制尚不清楚。我们在这里证明，在 NTC 过程中，非神经表面上皮沿着背腹轴施加的拉力方向移动。我们发现这种力部分归因于非神经外胚层细胞的深层，它们与表层一起共同向背中线移动。此外，通过删除整合素来抑制这种运动。 1 功能导致 NTC 不完整。此外，我们证明了其他提出的机制，例如定向细胞分裂、细胞重排和细胞形状变化在非神经运动中没有或仅发挥很小的作用。这项研究首次证明了非神经外胚层中的背侧深层细胞迁移，并表明 NTC 涉及胚胎组织的整体重组。
In developing vertebrates, the neural tube forms from a sheet of neural ectoderm by complex cell movements and morphogenesis. Convergent extension movements and the apical constriction along with apical-basal elongation of cells in the neural ectoderm are thought to be essential for the neural tube closure (NTC) process. In addition, it is known that non-neural ectoderm also plays a crucial role in this process, as the neural tube fails to close in the absence of this tissue in chick and axolotl. However, the cellular and molecular mechanisms by which it functions in NTC are as yet unclear. We demonstrate here that the non-neural superficial epithelium moves in the direction of tensile forces applied along the dorsal-ventral axis during NTC. We found that this force is partly attributable to the deep layer of non-neural ectoderm cells, which moved collectively towards the dorsal midline along with the superficial layer. Moreover, inhibition of this movement by deleting integrin. 1 function resulted in incomplete NTC. Furthermore, we demonstrated that other proposed mechanisms, such as oriented cell division, cell rearrangement and cell-shape changes have no or only minor roles in the non-neural movement. This study is the first to demonstrate dorsally oriented deep-cell migration in non-neural ectoderm, and suggests that a global reorganization of embryo tissues is involved in NTC.