Fig. 9. Analysis of the sexual differentiation phenotype in mutants with somatic cell-restricted loss of β-catenin. (A,B) Whole-mount ISH with the indicated RNA probes was performed with XX E12.5 gonads from wild-type and Sf1-Cre/β-cat^flox/flox (where β-cat is Ctnnb1) mouse embryos (A) or with E13.5 XY gonads from wild-type and XX Sf1-Cre/β-cat^flox/flox embryos (B) to examine the status of the female (A) and the male (B) pathway in XX gonads upon β-catenin loss. (C) qRT-PCR analysis of gene expression in the XX E12.5 wild-type and Sf1-Cre/β-cat^flox/flox gonads. The data are shown as the ratio of normalized expression (gene/Gapdh RNA copy number) in wild-type over mutant samples. The combined ^*Wnt4 level in the gonad-mesonephros block does not change; see the corresponding panel in A for gonadal Wnt4 expression. (D,E) Double immunofluorescent staining of E18.5 gonadal sections for either H2AX (D; red) or SYN/COR (E; red) and PECAM1 (green). The wild-type E18.5 ovary contains numerous germ cells with H2AX (D, top panel) or SYN1 (synapsin I) staining (E, top left). In the XX Sf1-Cre/β-cat^flox/flox XX gonad, germ cells are largely lost; no SYN1-positive cells are observed in the control or Sf1-Cre/β-cat^flox/flox testis.