Serafini T, Colamarino S A, Leonardo E D, Wang H, Beddington R, Skarnes W C, Tessier-Lavigne M
Howard Hughes Medical Institute, Department of Anatomy, University of California, San Francisco 94143-0452, USA.
Cell. 1996 Dec 13;87(6):1001-14. doi: 10.1016/s0092-8674(00)81795-x.
During nervous system development, spinal commissural axons project toward floor plate cells and trochlear motor axons extend away from these cells. Netrin-1, a diffusible protein made by floor plate cells, can attract spinal commissural axons and repel trochlear axons in vitro, but its role in vivo is unknown. Netrin-1 deficient mice exhibit defects in spinal commissural axon projections that are consistent with netrin-1 guiding these axons. Defects in several forebrain commissures are also observed, suggesting additional guidance roles for netrin-1. Trochlear axon projections are largely normal, predicting the existence of additional cues for these axons, and evidence is provided for a distinct trochlear axon chemorepellent produced by floor plate cells. These results establish netrin-1 as a guidance cue that likely collaborates with other diffusible cues to guide axons in vivo.
在神经系统发育过程中，脊髓连合轴突向底板细胞投射，而滑车运动轴突则远离这些细胞延伸。Netrin-1是一种由底板细胞产生的可扩散蛋白，在体外可吸引脊髓连合轴突并排斥滑车轴突，但其在体内的作用尚不清楚。Netrin-1缺陷小鼠在脊髓连合轴突投射中表现出缺陷，这与Netrin-1引导这些轴突一致。还观察到几个前脑连合的缺陷，提示Netrin-1具有额外的引导作用。滑车轴突投射在很大程度上是正常的，这预示着这些轴突存在其他引导线索，并且有证据表明底板细胞产生一种独特的滑车轴突化学排斥物。这些结果确立了Netrin-1作为一种引导线索，它可能与其他可扩散线索协同作用以在体内引导轴突。
