Video 6.
Intravital dynamics of GFP-tubulin in two skeletal muscle FDB fibers. A mouse whose FDB had been injected with GFP-tubulin cDNA and electroporated 6 d earlier was anesthetized. A skin flap was removed from the sole of the foot to expose the FDB. The animal was placed in a custom-made insert on the stage of a TCS SP5 laser-scanning confocal microscope and kept at 37°C with a heating lamp. A glass coverslip separated foot and objective lens. Two neighboring fibers were imaged simultaneously. The plane of focus intersected one of them (top) near the surface and the other one (bottom) in the core. The time-lapse sequence was recorded at one frame every 2.6 s for 44 s. Arrowheads point to pockets of growing MTs. Additional technical parameters are listed in Table S1. Bar, 10 µm.