Figure 1.

Histochemical staining sections of gastrocnemius muscle in mice. (a) Antimyosin heavy chain IIa; (b) and (c) hematoxylin and eosin staining; (d) identification of satellite cells by immunohistochemical triple staining. Only Type IIx/b fibers were present in the muscle (most superficial portion in (a)), while muscle fibers in the deep portion consisted of Types I, IIa, and IIx/b (small portion deeper than connective tissue (CT)). Many fibers with central nuclei (white arrows) were found in Cu/Zn superoxide dismutase (SOD1) knockout (KO) mice (c) but not in control (CTL) mice (b). Satellite cells (white arrows) were identified as stained positive for both DAPI (blue) and Pax7 (red) at the periphery of each fiber beneath the basal lamina (green) in (d).