Fig. 6.

Markers of autophagy in the quadriceps muscles of 15-month SED, 23-month SED, and 23-month RWE mice, of both sexes. P-ULK1(Ser757) was quantified relative to t-ULK1 (a, b), and t-ULK1 to the loading control GAPDH (a, c). Ratios of LC3II/LC3I were detected in the 1% NP40 soluble protein fraction, with GAPDH displayed to demonstrate equal loading (a, d). Protein amounts of p62 were quantified in both the 1% NP40 soluble and insoluble fractions, and standardized relative to GAPDH and Ponceau S (stained band between 50 and 37 kDa), respectively (a, e, f). Data were analyzed by ANOVA, using age and sex and sex and activity as variables. Data are mean ± SEM. Asterisk denotes significance at *P < 0.05; **P < 0.01; ***P < 0.001. For each age group, N = 6–10 mice/group. Y-axes represent arbitrary units