Module 4: Figure MyoD and muscle differentiation

The role of MyoD in skeletal muscle differentiation.

MyoD is one of the myogenic regulatory factors (MRFs) that control muscle differentiation. MyoD binds to the E-box, which is a DNA motif (CANNTG) found on the promoters of many muscle-specific genes. MyoD is expressed in myoblasts early in muscle development when mesodermal cells acquire a myogenic lineage. Since these myocytes continue to proliferate early in development, differentiation is kept in abeyance by various mechanisms that inhibit the activity of this potent myogenic factor. (See the text for details of the mechanisms in the two panels.)