Fig. 9. A short-term application of melittin but neither penetratin nor oleic acid to Myomerger-deficient myoblasts synchronized by LPC promotes complete fusion of myoblasts.

a Schematic showing synchronized myoblast fusion assay. b Differentiating Myomerger-deficient cells were accumulated upstream of hemifusion by the incubation in the presence of lysophosphatidylcholine (LPC). After 3 days in the differentiation medium (DM), LPC-supplemented DM was replaced with LPC-free DM supplemented or not with melittin (Mel) or penetratin (Pen) or oleic acid (OA). 60 min later we fixed the cells and scored fusion as the ratio of nuclei in the cells with ≥2 nuclei to the total number of nuclei. N, the number of randomly selected fields of view examined for each condition over two independent cell preparations, is indicated to the left of the box associated with that data. Box-and-whisker plots show median (center line), mean (blue line), 25–75th percentiles (box), 10–90th percentiles (whiskers), and 5–95th percentiles (solid circles). P-values were calculated using a two-tailed unpaired t-test. c Representative images for the experiments in b taken for the control cells and for the cells treated with 0.25 μM Mel or 10 μM Pen or 10 μM OA. Arrows mark examples of fusion. Scale bar 50 μm.