Figure 3.

Primary regulators of satellite cell proliferation and differentiation in vitro. Satellite cell isolates from meat-producing livestock cultured in permissive media with the FGF2 (green) elicit a strong proliferative response with a corresponding inhibition of differentiation. Modest mitogenic and myogenic actions are found for IGF-I (blue) with TGF-β (red) serving as a general inhibitor of proliferation and a strong suppressor of differentiation. Scale +1 denotes maximal positive response and −1 maximal inhibitory response.