Figure 1.

Generation of p53^S18/23A knockin mice. (A) The endogenous mouse p53 locus. (B) The targeting construct. The PGK-Neo^R cassette flanked by two loxP sites was inserted into intron 4. S18/23A mutations are indicated by asterisks. (C) The targeted p53 locus following homologous recombination between the endogenous p53 allele and targeting vector. (D) Knockin p53 allele following LoxP/Cre-mediated deletion of the PGK-Neo^R gene. (E) PCR analysis of the genomic DNA isolated from the tails of WT (lane 1), p53^S18/23A/+ (lane 2) and p53^S18/23A mice (lane 3). The PCR products depicting the WT and knockin mutant allele are indicated to the right. The primers are indicated by arrowheads. (F) The number of offsprings in various genotypes derived from the breeding of p53^S18/23A/+ mice. The expected number based on the Mendelian ratio is also shown.