Fig. 1. Wnt5a mutant FRTs lack posterior structures. Hoxa10 whole-mount in situ hybridization of the FRT from wild-type (A,C) and Wnt5a^-/- (B,D) at P0. The Wnt5a mutant FRT lacks cervical and vaginal structures and the uterine horns are short and convoluted. Arrows in C and D indicate the anterior limit of Hoxa10 expression at the uterotubal junction. Scale bars: 1 mm in A,B; 0.4 mm in C,D. Msx1 (E,F), Wnt7a (G,H), Wnt4 (I,J) and Wnt5a (K,L) ³⁵S in situ hybridization of paraffin wax embedded sections from wild-type (E,G,I,K) and Wnt5a mutant (–/–) (F,H,J,L) P0 FRTs. Silver grains are superimposed as red upon a phase contrast image. Ao, aorta; ce, cervix; ova, ovary; ovi, oviduct; ur, ureter; ut, uterus; va, vagina. Scale bar: 200 µm in E-L.