Figure 5. Expression of BubR1, a juvenile protective factor, in the gastrocnemius of young (2-3 mos), middle aged (13.5 mos) and aged (20 mos) WT and DN-p38AF/+ mice. (A: upper panel) Levels of BubR1 expression in WT gastrocnemius decline with age. (A1) young (2 mos), (A3) middle aged (13.5 mos), and (A5) aged (20 mos); (A: lower panel) Levels of BubR1 expression in the gastrocnemius of DN-p38αAF/+ mice. (A2) young (2 mos); (A4) middle aged (13.5 mos); and aged (A6). (B) A bar graph presentation of the western blot data in (C). Data are presented as relative OD vs. β-actin levels. *p < 0.05 vs. corresponding WT. (C) Western immunoblot analyses of the levels of BubR1 in young (2.0 mos), middle aged (13.5 mos) and aged (20 mos) WT and DN-p38αAF/+ mice. (GM, right leg). *p = 0.05 vs. WT of the same age.