FIG 8.
Muscle histopathology, mouse activity, and muscle atrophy gene expression of HSACrePofut1FF mice. (A) Quantification of myofibers with central nuclei at various ages. The line at 5% represents the normal range. (B) Assay of serum creatine kinase (CK) activity before and after 30 min of treadmill running at constant speed. (C) Open field measures of mouse activity and movement at various ages. Amb, ambulation; Periph, peripheral. (D) qRT-PCR measures of relative changes in muscle atrophy and autophagy gene markers, including the tripartite motif-containing 63 (Trim 63), F-box protein 32 (Fbxo32), autophagy-related 5 (Atg5) and 12 (Atg12), and beclin 1 (Becn1) genes, in the Gastroc muscles of 2-, 9-, and 17-month-old (mo) mice. Gene expression was not determined for 9-month-old HSACre muscles. Error bars show SEM (n = 4 or 5 [A], 7 to 11 [B], 4 [C], or 9 [D] samples per condition). *, P < 0.05; **, P < 0.01; ***, P < 0.001.