Fig. 5. Comparative expression of Wnt pathway genes in Gata4/Fog2 and Wnt4 mutants. (A-D) The GATA4-FOG2 complex is essential for canonical β-catenin signaling. Gonads from E12.5 mouse embryos carrying Axin2^lacZ and either wild-type (A,B) or homozygous mutant (C,D) Fog2 were stained with X-Gal, which labels Axin2^lacZ-positive cells. Only the ovary (B) is positive for Axin2^lacZ expression. (E-L) ISH was performed with the indicated probes on XX gonads from wild-type, Gata4^ki/ki and Fog2^-/- E12.5-13.5 embryos. (M) qRT-PCR analysis of Sp5, Irx3 and Rspo1 gene expression in wild-type and Gata4^ki/ki E12.5 XX gonads. (N) qRT-PCR analysis of gene expression in wild-type and Wnt4^-/- E12.5 gonads.