PGC-1α KO animals have lower mitochondrial content and display myopathic features. (A) TA muscle mass corrected for body weight. (B) Cytochrome C oxidase activity. (C) Representative images of COX staining of EDL muscle from Con and Den WT and KO animals. (D) Representative images of SDH staining of EDL muscle from Con and Den WT and KO animals. (E) EM images of control WT (top left panel) and PGC-1α KO muscle (top right and bottom two panels). PGC-1α KO animals display a myopathic phenotype characterized by the accumulation of multivesicular bodies (top right), aberrant mitochondria (bottom left) as well as tubular aggregates (bottom right). *P < 0.05, significant effect of denervation. †P < 0.05, significant effect of genotype (n = 4 to 8 for all groups). Con, control; COX, cytochrome C oxidase; Den, denervated; KO, knockout; TA, tibialis anterior; WT, wild type.