Figure 6. Ultrastructure of mitochondria in skeletal muscle of 11-year-old naked mole rat. (A) Longitudinal section of muscle fiber. Arrows 1 indicate large clusters of mitochondria located along myofibrils; arrows 2 indicate large clusters of mitochondria in the perinuclear and subsarcolemmal areas. Mitochondrion which specific ultrastructure is demonstrated under higher magnification in