ABSTRACT
Objective To investigate the cell-fusion modes and contractive characteristics of myotubes formed by muscle satellite cells in vitro. Methods The muscle satellite cells in quadriceps femoris of six 2-day-old SD rats were isolated, cultured and identified by immunofluorescence; the cell-fusion modes and contractive characteristics of myotubes were observed and recorded under microscope. Results The positve cells expressing marker Pax7 were obtained by immunofluorescence, and the purity was 90.3%. Myotubes were fused by several cells, cell and myotube or myotube and myotube. There were myotubes of spontaneous contraction on the conditions of no acetylcholine, no electric stimulation or no contiguous cells. Conclusion The myotubes of spontaneous contraction are fused by muscle satellite cells through three cell-fusion modes in vitro.