Neural crest emigration from the neural tube depends on regulated cadherin expression.
Neural crest emigration from the neural tube depends on regulated cadherin expression.
复制标题
神经嵴从神经管的迁移取决于调节的钙粘蛋白表达。
作者：
S. Nakagawa;M. Takeichi
在神经嵴细胞从神经管中出现的过程中，钙粘蛋白的表达发生动态变化。在鸡胚胎中，早期神经管在神经嵴细胞产生的最背侧区域表达两种钙粘蛋白，N-钙粘蛋白和钙粘蛋白-6B（cad 6 B）。然而，这两种钙粘蛋白的表达在从神经管迁移的神经嵴细胞中下调;它们开始表达钙粘蛋白7（cad 7）。为了研究这些变化在钙粘蛋白表达中的作用，我们在神经嵴生成细胞中过表达了各种钙粘蛋白结构，包括N-钙粘蛋白、cad 7和显性负性N-钙粘蛋白（cN 390）。这是通过将编码这些分子的腺病毒表达载体注射到第14阶段鸡胚的闭合神经管的内腔中来实现的。在注射病毒的神经管中，在神经嵴形成区域观察到有效的感染，导致迁移的神经嵴细胞中也出现异位钙粘蛋白表达。值得注意的是，异位钙粘蛋白的神经嵴细胞的分布变化取决于表达的结构。当N-cadherin或cad 7过表达时，许多嵴细胞未能从神经管中逃逸。此外，这些异位钙粘蛋白的细胞迁移沿着背外侧（黑素细胞）的途径。当这些样本进行Mitf染色，一种早期黑素细胞标记物，发现阳性细胞在神经管内积累，表明它们迁移的失败不是由于分化缺陷。与这些现象相反，表达非功能性钙粘蛋白的细胞表现出正常的迁移模式。因此，神经上皮钙粘蛋白（N-钙粘蛋白）和嵴钙粘蛋白（cad 7）的过度表达导致神经嵴从神经上皮细胞分离的相同阻断作用，特别是对于黑素细胞前体。这些结果表明，在神经嵴形成区的钙粘蛋白表达或其活性的调节起着至关重要的作用，在神经嵴从神经管迁移。
During the emergence of neural crest cells from the neural tube, the expression of cadherins dynamically changes. In the chicken embryo, the early neural tube expresses two cadherins, N-cadherin and cadherin-6B (cad6B), in the dorsal-most region where neural crest cells are generated. The expression of these two cadherins is, however, downregulated in the neural crest cells migrating from the neural tube; they instead begin expressing cadherin-7 (cad7). As an attempt to investigate the role of these changes in cadherin expression, we overexpressed various cadherin constructs, including N-cadherin, cad7, and a dominant negative N-cadherin (cN390 ), in neural crest-generating cells. This was achieved by injecting adenoviral expression vectors encoding these molecules into the lumen of the closing neural tube of chicken embryos at stage 14. In neural tubes injected with the viruses, efficient infection was observed at the neural crest-forming area, resulting in the ectopic cadherin expression also in migrating neural crest cells. Notably, the distribution of neural crest cells with the ectopic cadherins changed depending on which constructs were expressed. Many crest cells failed to escape from the neural tube when N-cadherin or cad7 was overexpressed. Moreover, none of the cells with these ectopic cadherins migrated along the dorsolateral (melanocyte) pathway. When these samples were stained for Mitf, an early melanocyte marker, positive cells were found accumulated within the neural tube, suggesting that the failure of their migration was not due to differentiation defects. In contrast to these phenomena, cells expressing non-functional cadherins exhibited a normal migration pattern. Thus, the overexpression of a neuroepithelial cadherin (N-cadherin) and a crest cadherin (cad7) resulted in the same blocking effect on neural crest segregation from neuroepithelial cells, especially for melanocyte precursors. These findings suggest that the regulation of cadherin expression or its activity at the neural crest-forming area plays a critical role in neural crest emigration from the neural tube.
DOI：
--
发表时间：
1983-04
期刊：
Journal of embryology and experimental morphology
影响因子：
--
作者：
C. Erickson;J. A. Weston
通讯作者：
C. Erickson;J. A. Weston
神经前体谱系指定了不同的新皮质锥体神经元类型。
DOI：
10.1523/jneurosci.0335-15.2015
发表时间：
2015
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Tyler,WilliamA;Medalla,Maria;Guillamon-Vivancos,Teresa;Luebke,JenniferI;Haydar,TarikF
通讯作者：
Haydar,TarikF
禽类神经嵴细胞只有在被指定为黑素细胞时才能在背外侧路径中迁移。
DOI：
10.1242/dev.121.3.915
发表时间：
1995
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Erickson,CA;Goins,TL
通讯作者：
Goins,TL