Fig. 1. Targeting strategy for generation of the Wnt7b^lacZ mice. (A) Schematic of Wnt7b targeting construct. (B) Southern blot of a litter of newborn mice indicating the wild-type allele (10 kb) and the mutant allele (5 kb), resulting from an EcoRI restriction enzyme digest. (C) RT-PCR analysis of mRNA from E14.5 mouse lungs from Wnt7b^lacZ–/– embryos. The Wnt7b^lacZ targeted allele and the oligonucleotide used for RT-PCR are shown. No amplifiable transcripts were obtained using oligo combinations A/C or A/E (data not shown) from Wnt7b^lacZ–/– embryos while wild-type (+/+) mRNA produced a robust signal. Low levels of transcript were obtained using oligos D and E with lung cDNA from Wnt7b^lacZ–/– embryos. (D) HEK-293 cells were transfected with either HA-tagged full-length or truncated (trunc) Wnt7b cDNAs. The truncated Wnt7b cDNA represented the complete coding region from the last three exons, which are still present in the Wnt7b^lacZ–/– allele. Cells are counterstained with DAPI to visualize the nucleus. Scale bar: 40 µm.