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研究人员从指定年龄的CHC22小鼠与野生型（Wild Type, WT）小鼠体内采集骨骼肌（腓肠肌），制备组织匀浆后采用免疫印迹（immunoblotting）技术，对I型、IIa/b型肌球蛋白重链，以及CHC22蛋白与内参甘油醛-3-磷酸脱氢酶（GAPDH）的表达水平进行检测。左侧展示了各年龄组的典型免疫印迹结果；右侧则呈现了对应年龄组4-5只实验动物的肌球蛋白重链（Myosin Heavy Chain, MyHC）亚型信号相对于GAPDH信号的相对定量结果。老年CHC22小鼠的I型肌球蛋白重链表达量显著下降，*p