Fig. 9. Combinatorial actions of Ascl1, Olig2 and Nkx2-2 in oligodendrocyte differentiation. (A-C) The percentages of cells with three distinct phenotypes among total virus-infected cells (mean±s.d. from three or four independent experiments). Viruses used for infection are shown on the left. (D) Promotion of oligodendrocyte differentiation by the combinatorial actions of Ascl1, Olig2 and Nkx2-2. The percentages of NG2⁺/GalC^- (pale colors on the left), NG2⁺/GalC⁺ (middle) and NG2^-/GalC⁺ (dark colors on the right) in the total oligodendrocyte lineage cells are compared between cultures infected with various viruses. ^*P<0.01 compared with the control virus; ^%P<0.01 compared with culture infected with Olig2 and Nkx2-2 viruses. ^$P<0.01 compared with culture infected with Ascl1 virus.