Fig. 2.

FGFRdn expression does not alter OPC differentiation into type 2 astrocytes. OPC cultures were infected with retrovirus and then grown in Dulbecco modified eagle medium (DMEM) with 10% FBS to promote OPC differentiation along the astrocytic pathway. A, B: Cells infected with either PMXs (A, green) or PMXs-FGFRdn (B, green) exhibited immunoreactivity for GFAP (red in A, B), characteristic of an astrocytic phenotype. The typical processed morphology of type 2 astrocytes (B, left side) contrasts with the flattened, fibroblastic morphology of type 1 astrocytes (B, right side). Scale bar = 20 μm. C: Quantitation of GFAP immunoreactivity shows a similar frequency of astrocytic differentiation among GFP expressing cells infected with PMXs compared with PMXs-FGFRdn (P ≫ 0.05; values shown are the mean of three independent experiments with at least 300 cells counted for each retrovirus condition).