Fig. 8. In vitro myoblast differentiation and fusion to myotubes is normal in gxi mutant mouse. (A) To assess the regenerative capacity of myoblasts, we cultured myoblasts from wild-type (WT), integrin 7 mutant (Itg7^–/–), -sarcoglycan mutant (gsg^–/–) and double mutant (gxi) neonatal mice. Each culture was differentiated to myotubes, and stained for dystrophin (green) and embryonic myosin heavy chain expression (red). Bar, 50 µm. (B) The fusion index was determined as described in Materials and Methods for each genotype and no significant differences were noted in the timing or degree of myoblast fusion to myotubes (P>0.05 for all comparisons).