Bernardoni R, Miller A A, Giangrande A
Institut de Génétique et Biologie Moléculaire et Cellulaire, IGBMC/CNRS/ULP-BP 163 67404 Illkirch, c.u. de Strasbourg, France.
Development. 1998 Aug;125(16):3189-200. doi: 10.1242/dev.125.16.3189.
Glial cells differentiate from the neuroepithelium. In flies, gliogenesis depends on the expression of glial cell deficient/glial cell missing (glide/gcm). The phenotype of glide/gcm loss- and gain-of-function mutations suggested that gliogenesis occurs in cells that, by default, would differentiate into neurons. Here we show that glide/gcm is able to induce cells even from a distinct germ layer, the mesoderm, to activate the glial developmental program, which demonstrates that gliogenesis does not require a ground neural state. These findings challenge the common view on the establishment of cell diversity in the nervous system. Strikingly, ectopic glide/gcm overrides positional information by repressing the endogenous developmental program. These findings also indicate that glial differentiation tightly depends on glide/gcm transcriptional regulation. It is likely that glide/gcm homologs act similarly during vertebrate gliogenesis.
神经胶质细胞由神经上皮分化而来。在果蝇中，神经胶质细胞生成依赖于神经胶质细胞缺陷/神经胶质细胞缺失（glide/gcm）的表达。glide/gcm功能丧失和功能获得突变的表型表明，神经胶质细胞生成发生在默认情况下会分化为神经元的细胞中。在此，我们表明，glide/gcm甚至能够诱导来自不同胚层（中胚层）的细胞激活神经胶质细胞发育程序，这表明神经胶质细胞生成并不需要基础神经状态。这些发现挑战了关于神经系统中细胞多样性建立的普遍观点。引人注目的是，异位的glide/gcm通过抑制内源性发育程序来超越位置信息。这些发现还表明，神经胶质细胞分化紧密依赖于glide/gcm的转录调控。很可能glide/gcm同源物在脊椎动物神经胶质细胞生成过程中发挥类似作用。
