Fig. 4.

Oxygen does not modulate myoregulatory factor gene expression in proliferating myoblasts. For all graphs, 5% oxygen culture conditions are represented by black bars and 20% oxygen culture conditions are represented by white bars. a, b *MyoD and myogenin gene expression was upregulated in proliferating myoblasts with time (p < 0.05; main effect time), indicating spontaneous differentiation with increasing cell density. MyoD and myogenin mRNA levels were similar in 5 and 20% oxygen at all time points measured