(A) Proliferation of primary myoblasts isolated from either C57BL/6 (black bars) or β₁/β₂-KO (white bars) mice.

<p>Myoblasts from β₁/β₂-KO mice proliferated more rapidly than those from C57BL/6 controls (*<i>P</i><0.05 compared with control, <i>t</i>-test, <i>n</i> = 6). (B) and (C) Differentiation of primary myoblasts isolated from either C57BL/6 (black bars) or β₁/β₂-KO (white bars) mice. Myoblasts from β₁/β₂-KO mice had significantly impaired differentiation compared with those from C57BL/6 controls (*<i>P</i><0.05 compared with control, <i>t</i>-test, <i>n</i> = 6).