Rescuing GT agenesis in Shh-/- embryos by restoring Hh responsiveness. (A-C) SEM analysis of E12.5 genital region of Shh-/- mouse embryos (A) and Shh-/- embryos with Hh responsiveness restored in UE (B) or in UE and mesenchyme together (C). Bilateral growth in the UEmes-rescued line is indicated by arrows in C. (D-F″) Whole-mount in situ hybridization on E11.5 UE-rescued Shh-/- (D′,E′,F′), UEmes-rescued Shh-/- (D″,E″,F″) and ShhCreesr/+ littermate control (D,E,F) GT. The rescued expression of Fgf8, Hoxa13 and Hoxd13 is indicated by arrows.