Normal induction and early migration of NCCs in Rbpj CKO mice. (A-L) Transverse sections through the upper neural tube (nt) at the 22 or 25 somite stage of E9.5 wild-type (WT) and Rbpj CKO mice with P75 (red) and β-gal (green) (A-F) or Sox10 (green) (G-L) antibodies and counterstained with Hoechst. Although Cre-mediated recombination has occurred in many P75+ and Sox10+ cells by this stage, loss of Rbpj does not appear to affect the expression of either protein. Arrows point to P75/β-gal (A-F) and P75/Sox10 (G-L) co-labeled migratory NCCs. Scale bars: 100 μm.