Fig. 1. BMP4 inhibits oligodendrocyte (OL) lineage commitment by neural progenitor cells. (A) EGF-generated neurosphere cells from E17 mice (A,B) were grown for 3 days in 10 ng/ml each of NT3, PDGF-AA and EGF. Cells were then dissociated and plated in media containing 2 ng/ml EGF in absence (A, parts a-c) or presence of 20 ng/ml BMP4 (A, parts d-f). Cells were stained for CNPase (A, parts a,d), MBP (A, parts b,e) and GFAP (A, parts c,f). (B) Cells were immunostained with OLIG1, NG2, CNPase, MBP, GFAP, and ß-tubulinIII, and the mean numbers of immunoreactive cells were determined. BMP4 treatment significantly reduced the number of all OL species while increasing the number of astrocytes. Scale bars represent means±s.e.m. of four independent experiments. Anova was done to determine significance (^*P<0.05).