Halter D A, Urban J, Rickert C, Ner S S, Ito K, Travers A A, Technau G M
MRC Laboratory of Molecular Biology, Cambridge, England.
Development. 1995 Feb;121(2):317-32. doi: 10.1242/dev.121.2.317.
We describe the cloning, expression and phenotypic characterisation of repo, a gene from Drosophila melanogaster that is essential for the differentiation and maintenance of glia function. It is not, however, required for the initial determination of glial cells. In the embryo, the gene, which encodes a homeodomain protein, is expressed exclusively in all developing glia and closely related cells in both the central and peripheral nervous systems. The only observed exceptions in the CNS are the midline glia derived from the mesectoderm and two of three segmental nerve root glial cells. Using a polyclonal antibody we traced the spatial and temporal pattern of the protein expression in detail. Embryos homozygous for null alleles of the protein exhibit late developmental defects in the nervous system, including a reduction in the number of glial cells, disrupted fasciculation of axons, and the inhibition of ventral nerve cord condensation. The expression of an early glial-specific marker is unaffected in such homozygotes. By contrast, the expression of late glial-specific markers is either substantially reduced or absent. The specificity of expression is also observed in the locust Schistocerca gregaria and is thus evolutionarily conserved.
我们描述了果蝇黑腹果蝇中一种名为repo的基因的克隆、表达及表型特征，该基因对神经胶质细胞功能的分化和维持至关重要。然而，它并非神经胶质细胞初始决定所必需的。在胚胎中，该基因编码一种同源结构域蛋白，仅在中枢神经系统和外周神经系统中所有发育中的神经胶质细胞及密切相关细胞中表达。在中枢神经系统中唯一观察到的例外是源自中胚层的中线神经胶质细胞以及三个节段神经根神经胶质细胞中的两个。我们使用多克隆抗体详细追踪了该蛋白表达的时空模式。该蛋白无效等位基因的纯合胚胎在神经系统中表现出晚期发育缺陷，包括神经胶质细胞数量减少、轴突束化紊乱以及腹侧神经索凝聚受到抑制。早期神经胶质细胞特异性标志物的表达在这类纯合子中不受影响。相比之下，晚期神经胶质细胞特异性标志物的表达要么大幅降低，要么缺失。在蝗虫沙漠蝗中也观察到了这种表达特异性，因此它在进化上是保守的。
