Figure 2.

ERK Activation Leads to Downregulation of Muscle-Specific Gene Expression and Promotes Epigenetic Changes during Reprogramming of Salamander Myotubes

(A) Left: schematic representation of the variation in Sox6 mRNA levels upon myogenic differentiation. Right: quantitative RT-PCR analysis of Sox6 (with two different primers, Sox6 1 and Sox6 2) in RNA extracts from purified A1 myotubes, normalized to Ef1-α or L27.

(B) Representative images of myotubes following immunostaining against dimethylated H3K9 and myosin heavy chain (MyHC) 1.5 days after the indicated treatments. Scale bar represents 50 μm.

(C) Western blot analysis of purified myotube extracts. Note the decrease in dimetH3K9 upon serum induction and its impairment when ERK signaling is inhibited. The relative amount of dimethylated H3K9 was quantified for the indicated treatments.

Values represent the mean ± SEM (^∗p < 0.05); n = 4 (A–C), where n indicates the number of independent experiments.