Proliferation precedes differentiation in IGF-I-stimulated myogenesis

Insulin-like growth factors (IGF-1) activate skeletal muscle cell proliferation first, and then triggers events which lead to the expression of muscle-specific genes in myogenic cell cultures. This was gleaned from a detailed analysis of gene expression in L6E9 myoblast cultures treated with IGF-1 to investigate the early events preceding the stimulation of myogenic differentiation by the growth factor.