Fig. 7. Defect in the co-expression of Olig2 and Nkx2-2 in Ascl1^-/- spinal cords. (A) Co-expression of Olig2 and Nkx2-2 in vivo at E16.5. Arrowheads indicate Nkx2-2⁺/Olig2⁺ cells in the ventral white matter. Scale bar: 50 µm. (B,C) Expression of Nkx2-2 in Olig2⁺ OLPs in vitro. Spinal cord cells were isolated from either E16.5 (B) or E18.5 (C) embryos, and the expression of Nkx2-2 in Olig2⁺ cells was compared between the wild type and Ascl1^-/- mutants at indicated time points. Data are mean±s.d. (n=3). ^*P<0.01 compared with DAP7; %P<0.01 compared with the wild type.