Figure 8. Muscle fiber type switch during aging of CHC22-mice.

Skeletal muscle (gastrocnemius) was harvested from CHC22-mice and WT mice at the indicated ages and tissue homogenate was analyzed by immunoblotting for Type I and Type IIa/b myosin heavy chains, as well as for CHC22 and loading control GAPDH. A typical immunoblot for each age group is shown at the left. Signals for myosin heavy chain (MyHC) type levels relative to GAPDH signals are shown at the right for 4–5 animals from the indicated age groups. The drop in Type I myosin heavy chain in aged CHC22 mice is significant, *p<0.05, by Student’s t test.