Figure 9. Expression of the p19Arf tumor suppressor gene in the gastrocnemius of young (2 mos), middle aged (13.5 mos) and aged (20 mos) WT and DN-p38αAF/+ mice. (A: upper panel) The levels of expression of the p19Arf tumor suppressor gene are significantly higher throughout the life span of WT mice compared to corresponding age-matched DN-p38αAF/+ mice. Data for WT mice are depicted in (A1) young (2 mos): (A3) middle aged (13.5 mos); (A5) aged (20 mos) WT mice; (A: lower panel) Data for DN-p38αAF/+ mice are depicted in (A2) young (2 mos); (A4) middle aged (13.5 mos) and aged (A6) aged (20 mos) mice. (B) Bar graphs presentation of the Western blot analyses in (C). Data are presented as relative OD vs. β-actin levels. *p < 0.05 vs WT of the same age. *p = 0.05 vs. WT of the same age. (C) Western blot analyses of the level of expression of p19Arf in gastrocnemius of young (2 mos); middle aged (13.5 mos) and aged (20 mos) WT and DN-p38αAF/+ mice.