Figure 1. Schematic representation of the myogenesis process.

Quiescent skeletal muscle satellite cell can become activated following stimuli. The skeletal myoblasts, express transcriptions factors Pax7 and Pax3, as well as the myogenic regulatory factors Myf5 and MyoD. Once committed to differentiation, myoblasts arrest cycling and loose expression of Pax7, Pax3 and Myf5. MRF4 is further required for hypertrophy of the new fibers.