Figure 4

miR-203 represses myoblast differentiation. (a) After cells were transfected with miR-203 mimic at GM and collected at DM3, the mRNA and protein expression of MHC and myogenin do not change. (b) After cells were transfected with miR-203 mimic at DM2 and collected at DM5, the mRNA and protein expression of myogenin is significantly reduced, whereas the expression of MHC is slightly reduced. (c) After cells were transfected with miR-203 mimic at DM4 and collected at DM7, the mRNA and protein expression of myogenin and MHC are both significantly reduced. (d) Microscopic images of myoblasts at DM7 that were transfected at DM4. After miR-203 transfection, many myoblasts remain mononucleated and do not fuse to each other. (e and f) Cells were fixed and immunostained for desmin after 3 day of miR-203 and control duplex transfection at DM4, and then were quantified for the desmin⁺ nuclei presented in cells with the indicated number of nuclei (f). (g) After cells were transfected with anti-miR-203 at GM and collected at DM3, the mRNA and protein expression of MHC and myogenin are both significantly increased. (h and i) Cells were fixed and immunostained for desmin after 3 days of anti-miR-203 and anti-NC transfection at GM, and then were quantified for the desmin⁺ nuclei presented in cells with the indicated number of nuclei (f).The nuclei were stained blue with DAPI. The results are expressed as the mean±S.E.M. of three replicates. *P<0.05; **P<0.01; ***P<0.001