Figure 2. Changes in the denervated muscle mass and fiber size after MTM transplantation. A, At 2 weeks after MTM injection into denervated rat gastrocnemius muscles, animals displayed less muscle mass loss than animals injected with empty vector-transfected cells or the vehicle only (*t=0.39, P=0.007 and t=2.37, P=0.04, respectively). B and C, no significant differences were found in muscle masses across all three experimental groups at 4 and 24 weeks after cell transplantation. D and E, The average cross-sectional muscle fiber area at 2 weeks post-injection was significantly larger in MTM-injected animals than in animals injected with empty vector-transfected MSCs or the vehicle only (*t=4.22, P=0.002 and t=2.24, P=0.049, respectively). E, There was no difference in the muscle fiber cross-sectional area at 4 and 24 weeks post-injection. Data are reported as means±SD of the ratios of measurements in denervated vs contralateral non-operated muscles of each animal. More comprehensive data analyses of the muscle mass and fiber cross-sectional area are provided in Supplementary Tables S1 and S2. MTMs, MyoG-transfected muscle satellite cells; MSCs, muscle satellite cells; MyoG, myogenin.