Fig. 5. Disturbed Ca²⁺ kinetics in NDST-1-defective myotubes. Primary myoblast cultures of wild-type and NDST-1^–/– embryos were differentiated for three days, and Indo-1 ratios of electrically induced Ca²⁺ spikes were recorded using a high-speed UV confocal laser scanning microscope. Normalized Indo-1 ratios of individual wild-type and NDST-1^–/– primary myotubes were averaged and plotted against time, thus generating representative ratio traces for both genotypes. Each point represents the average value (wild type, n=12; NDST-1^–/–, n=8).