Figure 5

The drebrin antagonist BTP2 inhibits myoblast differentiation. (A) Primary myoblasts were cultured in differentiation medium for 72 hours in the presence or absence of the drebrin inhibitor BTP2 (5 μM), then fixed and stained for myosin heavy chain (MHC) (red) and drebrin (green). Nuclei were counterstained with 4',6-diamidino-2-phenylindole (blue). (B) Quantification of the fusion index in cultures from part (A). Values shown are means ± SD of triplicate determinations. *P < 0.01. (C) Cultures parallel to those in part (A) were examined by Western blot analysis for drebrin, myogenin and MHC production. Tubulin was used as a loading control. (D) through (F) are the same as (A) through (C), except C2C12 cells were used. The asterisks in (E) refer to differences between dimethyl sulfoxide- and BTP2-treated cells in each of the indicated categories.