Fig. 1. Expression of Nkx2.2 in developing mouse spinal cords shown by in situ hybridization. (A) E10.5; (B) E13.5; (C) E15.5; (D) P0; (E) P4; (F-H) P8. (G,H) Higher magnification of F at the lateral (G) and ventral (H) positions. Nkx2.2-positive cells start to migrate away from the ventricle at E13.5 into both gray matter (arrow, B) and the ventral and lateral white matter (arrowheads, B,C).