VARIATIONS IN THE DISTRIBUTION OF SUGAR RESIDUES IN THE ZONA-PELLUCIDA AS POSSIBLE SPECIES-SPECIFIC DETERMINANTS OF MAMMALIAN OOCYTES

The lectin-binding patterns of mammalian zonae pellucidae were investi gated to determine whether differences reflected their characteristic carbohydrate distribution patterns. Ovaries isolated from rodents (mou se, rat and hamster), rabbits, cats, dogs and pigs were fixed with glu taraldehyde and embedded in paraffin wax. Sections 5 mu m, were depara ffinized, rehydrated and labelled with ten different biotinylated lect ins as probes and avidin-biotin peroxidase complex as visualant. The z onae pellucidae of all animals studied exhibited species-specific vari ations in lectin-binding patterns, whereas the lectin binding of their granulosa cells and follicular fluids were identical. Phylogeneticall y close species, such as the rodents and rabbits demonstrated high sim ilarity in zona pellucida saccharides, expressed in binding of succiny lated wheatgerm agglutinin and peanut agglutinin. Lectins such as Doli chos biflorus agglutinin, which binds only to mouse, Griffonia simplic ifolia (GS-I), which binds to mouse and rat but not hamster and rabbit and soybean agglutinin, which binds only to rodents, reflect characte ristic differences between phylogenetically related mammals.