Mitochondrial matrix dynamics in a rat myotube. FDB fibers plated onto polylysine-coated (Sigma-Aldrich) and laminin-coated (Invitrogen) coverslips (100 µg/ml each; ∼20 coverslips/rat). Satellite cells were infected with the adenoviruses AdmtDsRed and AdmtPA-GFP and were allowed to differentiate to myotubes. Two regions of 5 × 5 µm2 were exposed to 2P photoactivation and recorded for 8 min using a laser-scanning confocal microscope (LSM780MP; Carl Zeiss). Frames were taken every 4 s.
