Fig. 3. Shh^-/- and Gli3^-/- mutants show opposite telencephalic phenotypes. Pan-ventral gene expression was analyzed in E10.5 Shh^-/- (A-F) and E12.5 Gli3^-/- (G-L) mutants. Dlx2 and Gsh2 expression is maintained but displaced ventrally in Shh^-/- embryos (B,D,F). By contrast, Dlx2 and Gsh2 expression expands dorsally in Gli3^-/- mutants (H,J,L). (K,L): Gsh2 and Pax6 expression domains abut at the corticostriatal boundary in wild-type animals (K, arrow). This boundary is affected in Gli3^-/- embryos (L), with Gsh2 expression expanding dorsally. Dlx2 expression was assayed either by X-gal staining on whole-mount embryos (A,B) or by in situ hybridization on coronal sections (C,D,G,H). Gsh2 expression was assayed by immunofluorescence against the Gsh2 protein (E,F,I-L).