Giniger E, Jan L Y, Jan Y N
Howard Hughes Medical Institute, University of California, San Francisco 94143.
Development. 1993 Feb;117(2):431-40. doi: 10.1242/dev.117.2.431.
The intersegmental nerve (ISN) of the Drosophila embryo follows a reproducible course near the anterior border of each segment. Based on the experiments reported here, we suggest that growth of the axons constituting the nerve is guided, in part, by the transmembrane proteins Delta and Notch. In particular, we suggest that expression of Delta protein on a branch of the trachea provides a path for the nerve through the lateral part of the embryo, and that the growing axons use the Notch protein on their surfaces to recognize this path. Consistent with this idea, we show that disruption of the trachea abolishes the ability of the ISN to extend through this part of the embryonic periphery. Finally, we argue that the same regulatory network that directs these peripheral axons also specifies the trajectory of part of the axonal scaffold of the central nervous system.
果蝇胚胎的节间神经（ISN）在每个节段的前缘附近遵循可重复的路径。基于此处报道的实验，我们认为构成该神经的轴突生长部分受跨膜蛋白Delta和Notch的引导。具体而言，我们认为气管分支上Delta蛋白的表达为神经提供了一条穿过胚胎侧面的路径，并且生长中的轴突利用其表面的Notch蛋白来识别这条路径。与这一观点一致，我们表明气管的破坏消除了ISN延伸穿过胚胎周边这一部分的能力。最后，我们认为指导这些外周轴突的相同调控网络也决定了中枢神经系统部分轴突支架的轨迹。
