Fig. 6. ‘Super p53’ mice age normally. (A) Survival at 2 years of wild-type mice and ‘super p53’ mice with three (p53^+/+;tg/·) or four (p53^+/+;tg/tg) p53 alleles. The genetic background of all the mice used for this measurement was mixed C57BL6:CBA, with an estimated contribution of C57BL6 of 87.5% (see Materials and methods). (B) Incidence of spontaneous tumors in wild-type and ‘super p53’ (p53^+/+;tg/·) mice. Moribund mice were killed and complete histopathological surveys were performed to determine the presence of tumors. (C) Hair regrowth in wild-type and ‘super p53’ (p53^+/+;tg/· and p53^+/+;tg/tg) mice of different ages. The figure shows the average percentage of shaved area repopulated with hair after a period of 20 days since shaving. (D) Evaluation of lordokyphosis in aged mice. X-ray radiographs of 24-month-old male mice of the indicated genotypes. The indicated angle of the spine cord was measured to standardize the comparisons (see E). (E) Lordokyphosis in wild-type and ‘super p53’ (p53^+/+;tg/·) mice of different ages. The figure shows individual measurements of the spine angle indicated in (D), in mice of different ages. A narrowing of the angle (see D) indicates an increase in lordokyphosis. (F) Aging of the skin in wild-type and ‘super p53’ (p53^+/+;tg/·) mice. The figure shows representative images of hematoxylin and eosin-stained sections of the skin from the indicated mice. Two mice were analyzed per age and genotype. The epidermis (E), dermis (D), adipose layer (A) and muscular layer (M) are indicated. Mice of 2 years of age show moderate thinning of the dermis, prominent thinning of the adipose layer and atrophy of some hair follicles. Original magnification 10×. (G) Osteoporosis of aged wild-type and ‘super p53’ (p53^+/+;tg/·) mice. The two top panels show representative images of hematoxylin and eosin-stained cross-sections of tibias from the indicated young mice. The two bottom panels show osteoporosis present in a fraction of wild-type (one out of three) and ‘super p53’ (one out of five) mice. The cortical bone (C), trabecular bone (T) and epiphyseal plate (P) are indicated. Bones with osteoporosis present thinning of the cortical bone and partial loss of the trabecular bone. Original magnification 4×.