Figure 3.
Overexpression of the short isoform of p53 in p44 transgenic mice. (A) p44 protein in transgenic and NT mice. Western blots of 100 μg thymus protein extracted from transgenic (P,Q) and NT (NT) tissues. The anti-p53 polyclonal antiserum CM5 detects both isoforms of p53, as indicated. Biotinylated markers were run alongside the tissue extracts during SDS-PAGE; the marker corresponding to 45 kD is shown. (B) p44 and p53 RNA in transgenic and NT mice. RNAse protection assay was used to detect both p53 (220-bp protected fragment) and p44 (140-bp protected fragment) RNA. Simultaneous hybridization to a probe that detects cyclophilin (Cyc) was used to control for assay conditions. Lu, lung; Li, liver; K, kidney; T, testis; M, marker RNA bands. (C) Effect of p44 on body size. Size of NT (top), hemizygous (middle), and homozygous (bottom) P mice at 3 mo of age. Organ weights of representative hemizygous (black bars) and homozygous (stippled bars) transgenic mice are plotted as a percentage of NT weights. Transgenic animals were generated on a p53+/+ background. (D) Genetic interaction of p44 and p53. Nontransgenic (top), hemizygous (middle), and homozygous (bottom) P mice generated on a p53-/- background. Organ weights of representative hemizygous (black bars) and homozygous (stippled bars) transgenic mice are plotted as a percentage of p53-/- weights.