Axon guidance by diffusible chemoattractants: A gradient of netrin protein in the developing spinal cord
Axon guidance by diffusible chemoattractants: A gradient of netrin protein in the developing spinal cord
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DOI：
10.1523/jneurosci.5191-05.2006
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发表时间：
2006-08-23
影响因子：
5.3
通讯作者：
Tessier-Lavigne, Marc
中科院分区：
文献类型：
--
作者：
Kennedy, Timothy E.;Wang, Hao;Tessier-Lavigne, Marc
已经提出了可扩散的长程吸引剂和排斥蛋白的梯度来指导神经系统发育期间的轴突生长，但这种梯度从未被直接可视化。在胚胎脊髓中，连合轴突在netrin家族的分泌蛋白的指导下，在腹侧中线处开拓到底板的周向轨迹。在鸡胚脊髓中，netrin-1 mRNA由底板细胞表达，netrin-2 mRNA由神经上皮细胞表达。两种netrin的抗体揭示了netrin蛋白直接在连合轴突的路径中的梯度。netrin-1梯度本身延伸许多细胞直径背侧的底板，netrin-1表达的网站。netrin-1蛋白在胚胎大鼠和小鼠脊髓中的分布相似。netrin-1蛋白梯度的检测支持在发育中的神经系统中的远程趋化机制的操作。
Gradients of diffusible long-range attractant and repellent proteins have been proposed to guide growing axons during nervous system development, but such gradients have never been visualized directly. In the embryonic spinal cord, commissural axons pioneer a circumferential trajectory to the floor plate at the ventral midline directed by secreted proteins of the netrin family. In the embryonic chick spinal cord netrin-1 mRNA is expressed by floor plate cells and netrin-2 mRNA by neural epithelial cells. Antibodies to the two netrins reveal a gradient of netrin protein directly in the path of commissural axons. The netrin-1 gradient itself extends many cell diameters dorsal to the floor plate, the site of netrin-1 expression. A similar distribution of netrin-1 protein has been detected in embryonic rat and mouse spinal cord. The detection of a gradient of netrin-1 protein supports the operation of long-range chemotropic mechanisms in the developing nervous system.