Fig. 1.
Design of the conditional targeting vector and strategy for disruption of the REA gene using PR-Cre. A, The targeting vector, described in more detail in the text, contains positive (NEO) and negative [thymidine kinase (TK)] selection markers, two frt sites that flank a neomycin resistant gene cassette (indicated as ovals), and two loxP sequences (triangles). The REAflox-frt-neo allele was created by homologous recombination in embryonic stem cells, and the REAflox/+ allele was derived from a REAflox-frt-neo allele through in vivo Flippase recombination enzyme (FLP)-mediated recombination. Finally, the PR-Cre mice were used to generate the conditional deletion of the REA gene by Cre-mediated excision in PR expressing cell lineages. B, Genomic DNA isolated from the indicated tissues was genotyped by PCR.