DPP signaling controls development of the lamina glia required for retinal axon targeting in the visual system of Drosophila
DPP signaling controls development of the lamina glia required for retinal axon targeting in the visual system of Drosophila
复制标题
DOI：
10.1242/dev.02040
复制
发表时间：
2005-10
期刊：
影响因子：
--
通讯作者：
S. Yoshida;L. Soustelle;A. Giangrande;Daiki Umetsu;S. Murakami;Tetsuo Yasugi;T. Awasaki;Kei Ito;Makoto Sato;T. Tabata
中科院分区：
文献类型：
--
作者：
S. Yoshida;L. Soustelle;A. Giangrande;Daiki Umetsu;S. Murakami;Tetsuo Yasugi;T. Awasaki;Kei Ito;Makoto Sato;T. Tabata
果蝇的视觉系统由复眼和大脑中的视神经节组成。在8个光感受器(R)神经元中，来自R1-R6神经元的轴突停在视叶最浅的神经节--板层的两层神经胶质细胞之间。尽管有人认为胶质板层是R轴突的中间靶点，但对这些细胞的发育机制知之甚少。我们发现DPP信号在这一过程中起着关键作用。DPP在板层靶区的边缘表达，那里是胶质前体驻留的地方。MedeA克隆突变、DPP信号转导或DPP信号在该区域的抑制导致R神经元投射模式和神经元板层形态的缺陷，这是由于胶质细胞板层分化缺陷所致。胶质细胞缺失/胶质细胞缺陷(GCM；也称为Glide)是在胶质前体细胞开始分化和迁移后不久表达的。它的表达依赖于DPP；GCM在DPP突变体或Medea克隆中减少或缺失，而DPP信号的异位激活诱导了GCM和repo的异位表达。此外，R轴突投射和板层胶质细胞发育受到GCM显性-负性形式表达的损害，这表明GCM确实控制着板层胶质细胞的分化。这些结果表明，DPP信号通过控制GCM的表达，介导了正确的R轴突投射模式所需的板层胶质细胞的成熟。
The Drosophila visual system consists of the compound eyes and the optic ganglia in the brain. Among the eight photoreceptor (R) neurons, axons from the R1-R6 neurons stop between two layers of glial cells in the lamina, the most superficial ganglion in the optic lobe. Although it has been suggested that the lamina glia serve as intermediate targets of R axons, little is known about the mechanisms by which these cells develop. We show that DPP signaling plays a key role in this process. dpp is expressed at the margin of the lamina target region, where glial precursors reside. The generation of clones mutant for Medea, the DPP signal transducer, or inhibition of DPP signaling in this region resulted in defects in R neuron projection patterns and in the lamina morphology, which was caused by defects in the differentiation of the lamina glial cells. glial cells missing/glial cells deficient (gcm; also known as glide) is expressed shortly after glia precursors start to differentiate and migrate. Its expression depends on DPP; gcm is reduced or absent in dpp mutants or Medea clones, and ectopic activation of DPP signaling induces ectopic expression of gcm and REPO. In addition, R axon projections and lamina glia development were impaired by the expression of a dominant-negative form of gcm, suggesting that gcm indeed controls the differentiation of lamina glial cells. These results suggest that DPP signaling mediates the maturation of the lamina glia required for the correct R axon projection pattern by controlling the expression of gcm.