Fig. 6. Transfection of C2C12 myoblasts with dominant mutants of lamin A prevents nuclear-envelope organization and inhibits myoblast differentiation. C2C12 myoblasts were transfected in triplicate experiments with wild-type (wt) lamin A or lamin A W520S. 24 hours after transfection, cells were induced to differentiate with 2% horse serum. At 24-hour intervals, cells were fixed and stained with anti-myogenin antibody and anti-FLAG antibody. Two hundred transfected cells were counted for strong staining of exogenous lamins in nucleoplasm (a) or at the nuclear envelope (b), or for expression of myogenin (c). Results show the mean ± the standard deviation from triplicate experiments.