Fig. 3.

Analysis of Sox2 expression and myelination in Sox2^HomoOE mice carrying two copies of the Sox2IRESGFP transgene. (A-H) Immunohistochemical analysis of sciatic nerves demonstrates that control nerves do not express GFP or Sox2 at P7 (A,B) or P60 (C,D), whereas Sox2^HomoOE nerves have high levels of GFP and Sox2 expression at both P7 (E,F) and P60 (G,H). Scale bar: 40 µm. (I,J) TEM images of control (I) and Sox2^HomoOE (J) nerves at P60. Scale bar: 5 µm. (K) Western blots of control and Sox2^HomoOE nerves at P7 and P60 showing reduction in Krox20, P₀ and MBP expression in vivo mediated by Sox2 expression in SCs. (L,M) G-ratio measurements (L) and numbers of unmyelinated axons greater than 1 µm in diameter (M) in control, Sox2^HetOE and Sox2^HomoOE nerves at P60. Two-sided two-sample Student's t-test; data from n=3 mice of each genotype; *P<0.05, ***P<0.005. (N) Sox2^HomoOE mice (black, on right of picture) were smaller at P60 compared with control animals. (O,P) Sox2^HomoOE animals (P) show hind limb clasping when lifted by the tail, which is characteristic of peripheral hypomyelination, when compared with control littermate (O).