Hidalgo Alicia, Learte Anabel R, McQuilton Peter, Pennack Jenny, Zhu Bangfu
Neurodevelopment Group, School of Biosciences, University of Birmingham, Birmingham, UK.
Brain Behav Evol. 2006;68(3):173-80. doi: 10.1159/000094086. Epub 2006 Aug 14.
Trophic interactions in the vertebrate nervous system enable the adjustment of cell number and axon guidance, targeting and connectivity. Computational analysis of the sequenced Drosophila genome failed to identify some of the main trophic factors, the neuregulins and neurotrophins, as well as many other genes. This provoked speculations that the Drosophila nervous system might not require such regulative interactions. Here we review abundant cellular, genetic and functional data that demonstrate the existence of both neurotrophic and gliatrophic interactions in the Drosophila nervous system. Glial survival is maintained by the epidermal growth factor receptor (EGFR) signaling pathway in response to the ligands Spitz, a transforming growth factor-alpha (TGF-alpha) signaling molecule, and Vein, a neuregulin homologue. Cellular and genetic evidence predicts the existence of neuronal trophic factors operating at least in the Drosophila embryo during axon guidance and, in the visual system, during the targeting of retinal axons in the brain.
脊椎动物神经系统中的营养相互作用能够调节细胞数量以及轴突的导向、靶向和连接。对已测序的果蝇基因组进行的计算分析未能识别出一些主要的营养因子、神经调节蛋白和神经营养因子，以及许多其他基因。这引发了人们的猜测，即果蝇神经系统可能不需要这种调节性相互作用。在这里，我们回顾了大量的细胞、遗传和功能数据，这些数据表明果蝇神经系统中存在神经营养和胶质营养相互作用。胶质细胞的存活通过表皮生长因子受体（EGFR）信号通路来维持，该通路对配体斯皮茨（一种转化生长因子-α（TGF-α）信号分子）和静脉（一种神经调节蛋白同源物）作出反应。细胞和遗传证据预测，至少在果蝇胚胎中，在轴突导向过程中以及在视觉系统中，在视网膜轴突向大脑的靶向过程中，存在神经元营养因子。
