EM study of cultured human skeletal muscle explants on 10 consecutive days after incubation made possible a record for the first time, the early events occurring during regeneration. After incubation, normal myonuclei underwent activation and dense granulation. Some myonuclei showed early transformation to presumptive myoblasts. The conclusion was that myonuclei transformed into myoblasts which developed into satellite cells (SC). These SC of myonuclear origin, proliferated, and fused forming myotubes that matured into myofibres, replacing damaged muscle. The findings have new implications for the current myoblast / cell transplant and gene transfer therapy research which may provide possible answers for muscular dystrophy in the future.