Figure 10

Function of BMP signaling during satellite cell differentiation. Quiescent satellite cells (green) do not respond to BMP signals. Upon activation, satellite cells express MyoD and respond to BMP signals with phosphorylation of p-Smad (red) and reduced differentiation. After satellite cell descendents are committed to differentiate (yellow) they express Myogenin and subsequently the BMP inhibitor Chordin. Upon inhibition of BMP signaling, myoblasts exit the cell cycle, fuse into myotubes and undergo terminal differentiation (purple). Postmitotic myonuclei (blue) irreversibly loose the competence to respond to BMP signals.