Fig. 6. (A) Embryos expressing truncated ß-catenin do not develop optimally, as indicated by fewer pups per litter. Bar graph depicting the mean number of pups per litter obtained from females producing oocytes expressing truncated ß-catenin (ß^F/ß^F;cre/Ø) and control females (ß^F/ß^F and ß^F/ß;cre/Ø). The number of litters recorded (n) in each group is indicated at the bottom of the graph. (B,C) The paternal alleles of ß-catenin and E-cadherin are activated sequentially. (B) Expression of E-cadherin in embryos lacking maternal E-cadherin (top) and control embryos (bottom). (C) Expression of wild-type ß-catenin in embryos expressing truncated ß-catenin (top) and control embryos (bottom). The expression of both genes was monitored by RT-PCR and subsequent Southern blot analysis of the PCR products using a ³²P-labeled E-cadherin cDNA probe. Wild-type ß-catenin was monitored using primers situated in sequences coding for the N-terminal part of the protein. The gene product monitored is indicated on top of the figure; the genotype of the females from which the embryos were isolated is indicated on the right. Mitochondrial ATP synthase (mt-Atp6) was used as a control for the RT-PCR, and was detected by ethidium bromide staining. Embryo stages are the same as in Fig. 2.