Fig. 9. Binding of GalT I-null sperm to the egg is independent of other members of the GalT family. UDP-galactose inhibits wild-type sperm, but not GalT I-null sperm, from binding to ovulated eggs. Each data point represents the mean±s.d.; n=2 experiments. In a single experiment, the value for each data point represents the average of three determinations (for a total of six assays per data point). UDP-glucose had no effect on the binding of either sperm genotype to eggs (data not shown).