Fig. 5.

ERK inhibition by PD98059 rescued MyHC expression and myotube formation during differentiation of emerin-null myogenic progenitors. (A) Timeline showing the timing of PD98059 addition and sample collection for western blot analysis of whole cell lysates during differentiation. (B-I′) Representative images of vehicle-treated wild-type (B-E) or emerin-null (F-I) cells and PD98059-treated wild-type (B′-E′) or emerin-null (F′-I′) cells 36 h after differentiation induction. 40× magnification. (J-L) Quantification of >1000 nuclei for each experimental treatment (n≥3) was done to determine the percentage of myogenic progenitors in the cell cycle (J), that are expressing MyHC (K), and formed myotubes (L) 36 h post-differentiation induction. Results are mean±s.d. of n≥3; N.S., not significant; *P<0.05, ***P<0.001 using paired, two-tailed t-tests.