Fig. 6. GalT I-null sperm do not require Ca²⁺ or HCO₃^– during capacitation to achieve maximal binding to the zona pellucida. Wild-type (gt +/+) and GalT I-null sperm (gt –/–) were capacitated in either albumin-free (A), Ca²⁺-free (B), HCO₃^– -free (C) or complete media (control) for varying amounts of time before incubation with ovulated eggs in complete media. Each bar represents the mean±s.e.m.; n=3 experiments. In a single experiment, the value for each data point represents the average of three determinations (nine assays in total). The average number of sperm bound to eggs at each time point was normalized to fully capacitated sperm (60 minutes of capacitation in complete media is equivalent to 100% bound).