Hughes S M, Raff M C
Department of Zoology and Cell Biology, University College London, UK.
Development. 1987 Sep;101(1):157-67.
In rat optic nerve, oligodendrocytes and type-2 astrocytes develop from a common (O-2A) progenitor cell. The first oligodendrocytes differentiate at birth, while the first type-2 astrocytes differentiate in the second postnatal week. We previously showed that the timing of oligodendrocyte differentiation depends on an intrinsic clock in the O-2A progenitor cell. Here we provide evidence that the timing of type-2 astrocyte differentiation, by contrast, may depend on an inducing protein that appears late in the developing nerve. We show that extracts of 3- to 4-week-old, but not 1-week-old, rat optic nerve contain a protein (apparent Mr approximately 25,000) that induces O-2A progenitor cells in culture to express glial fibrillary acidic protein (GFAP), an astrocyte-specific marker in the rat central nervous system.
在大鼠视神经中，少突胶质细胞和2型星形胶质细胞均由一种共同的（O-2A）祖细胞发育而来。首批少突胶质细胞在出生时分化，而首批2型星形胶质细胞在出生后第二周分化。我们先前表明，少突胶质细胞分化的时间取决于O-2A祖细胞中的内在时钟。相比之下，我们在此提供的证据表明，2型星形胶质细胞分化的时间可能取决于一种在发育中的神经后期出现的诱导蛋白。我们发现，3至4周龄而非1周龄大鼠视神经的提取物含有一种蛋白质（表观分子量约为25,000），该蛋白质可诱导培养中的O-2A祖细胞表达胶质纤维酸性蛋白（GFAP），GFAP是大鼠中枢神经系统中的一种星形胶质细胞特异性标志物。
