Fig. 6. Kinetics of expression of RyRs during differentiation of embryonic and fetal myoblasts in culture. The number of nuclei in RyR1- and RyR3-positive cells (plotted together, since both curves overlap) or in MyHC-positive cells in embryonic and fetal myoblasts in primary cultures were counted at each time point and expressed as a percentage of the total number of nuclei. At least 20 random microscopic fields were counted for each sample in three independent experiments. Triangles: embryonic myoblasts; circles: fetal myoblasts; filled simbols: RyRs; empty simbols: MyHC. Bars indicate s.d.