Contact inhibition/collapse and pathfinding of neural crest cells in the zebrafish trunk.
Contact inhibition/collapse and pathfinding of neural crest cells in the zebrafish trunk.
复制标题
斑马鱼躯干神经嵴细胞的接触抑制/崩溃和寻路。
作者：
S. Jesuthasan
脊椎动物胚胎主干的神经嵴细胞从神经管中迁移后，有多种途径可供选择：既可以沿体突与神经管之间的内侧途径迁移，也可以沿体突与表皮之间的外侧途径迁移。在斑马鱼胚胎中，最先迁移的细胞都选择中间通道。活胚胎细胞的高分辨率成像表明，神经嵴细胞之所以这样做，是因为体体的排斥作用：细胞选择内侧通路，是因为体体外侧表面触发了突起的麻痹和收缩（接触抑制或塌陷），而内侧表面则没有。体体的部分缺失，利用spadetail突变允许早熟进入外侧通路，但仅在体体缺失的地方，支持了体体上的抑制性提示延迟进入的概念。罗洪-比尔德细胞的生长锥比神经嵴细胞更早进入外侧通路，表明没有绝对的迁移障碍。这些数据，除了提供了神经嵴细胞在体内迁移的详细图片外，还表明神经嵴细胞，就像神经元生长锥一样，是由一个特定的线索引导，触发活动突起的“崩溃”。
Neural crest cells in the trunk of vertebrate embryos have a choice of pathways after emigrating from the neural tube: they can migrate in either the medial pathway between somites and neural tube, or the lateral pathway between somites and epidermis. In zebrafish embryos, the first cells to migrate all choose the medial pathway. High resolution imaging of cells in living embryos suggests that neural crest cells do so because of repulsion by somites: cells take the medial pathway because the lateral somite surface triggers a paralysis and retraction of protrusions (contact inhibition or collapse) when the medial surface does not. Partial deletion of somites, using the spadetail mutation allows precocious entry into the lateral pathway, but only where somites are absent, supporting the notion that an inhibitory cue on somites delays entry. Growth cones of Rohon-Beard cells enter the lateral pathway before neural crest cells, demonstrating that there is no absolute barrier to migration. These data, in addition to providing a detailed picture of neural crest cells migrating in vivo, suggest that neural crest cells, like neuronal growth cones, are guided by a specific cue that triggers 'collapse' of active protrusions.