(C) MitoTracker (red) and LC3immunostaining (green) of myotubes at DM-2. Chloroquine and 3-MA (where indicated) were added 12 h before staining. Note the extensive overlap of MitoTracker and LC3 in Rb−/−myotubes (yellow), which is inhibited by 3-MA. (D) Mean percentage of MitoTracker (red) to LC3 (green) overlap in 25 myotubes from two independent cultures in control versus Rb−/−myotubes (total) or Rb−/−myotubes with perinuclear mitochondrial aggregation (high). *, P = 7 × 10−5 by Student's t test. 