Figure 2.

Conditional p53 Mutant Transgenic Mouse Model

(A) Schematic illustration of targeting construct. Trp53 exons 5–11 were flanked by loxP sites (triangle). pA indicates an additional transcriptional STOP cassette. The engineered Trp53 duplicate region contains R245W mutations in exon 7, a C-terminal in-frame self-cleaving T2A peptide and enhanced GFP (eGFP). The conditional knockin (cKI) Trp53 allele was obtained after Flp-mediated deletion of the selection markers. Closed triangle and gray triangle indicate FRT site and F3 site, respectively. Prior to induction, the cKI allele expresses the wild-type Trp53 protein; however, after cre-mediated recombination, the allele co-expresses Trp53^R245W mutant protein and eGFP.

(B) Genetic lineage tracing in Ahcre^ERTp53^∗/wt mice. Cre-mediated recombination, induced by β-napthoflavone (βNF) and tamoxifen (Tam), results in expression of the mutant protein in place of the wild-type. The heritable expression of the mutant protein and GFP reporter allows the study of competition between mutant clones and the surrounding wt cells.

See also Figures S4 and S5 and Table S1.