Fig. 3

The phosphorylation level of JNK/MAPK signaling pathway are downregulated during developing mouse embryos muscle and primary skeletal muscle cell differentiation. a The protein expression levels of myogenic markers (MyoD and MyoG) in developing mouse embryos muscle. Mouse hind limb muscles were isolated from seven time points: E12.5, E15.5, E18.5, postnatal 1 week, postnatal 2 weeks, postnatal 4 weeks, and postnatal 8 weeks (adult). b Western blotting for phosphorylation level of JNK/MAPK signaling: JNK, c-JUN, and their phosphorylated forms p-JNK and p-c-JUN in developing mouse embryos muscle. c Relative expression in a and b were calculated. Data in the same group were compared to E12.5. GAPDH was the internal control. d The protein expression levels of myogenic markers (MyoD and MyoG) during primary skeletal muscle cell differentiation. MuSCs were isolated from hind limb muscles in postnatal 1-week mice, and then the cells were activated in vitro for expansion of myogenic progenitors (D0) and subsequently to differentiation (D1 to D8). e Western blotting for phosphorylation level of JNK/MAPK signaling: JNK, c-JUN, and their phosphorylated forms p-JNK and p-c-JUN during primary skeletal muscle cell differentiation. f Relative expression in d and e were calculated. Data in the same group were compared to D0 (except for MyoD was compared to D2). GAPDH was the internal control. Values are means ± SEM. The statistical significance of difference between two means was calculated with the t-test, *p < 0.05; **p < 0.01