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 investigated to determine whether differences reflected their characteristic carbohydrate distribution patterns. Ovaries isolated from rodents (mouse, rat and hamster), rabbits, cats, dogs and pigs were fixed with glutaraldehyde and embedded in paraffin wax. Sections 5 μm, were deparaffinized, rehydrated and labelled with ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex as visualant. The zonae pellucidae of all animals studied exhibited species-specific variations in lectin-binding patterns, whereas the lectin binding of their granulosa cells and follicular fluids were identical. Phylogenetically close species, such as the rodents and rabbits demonstrated high similarity in zona pellucida saccharides, expressed in binding of succinylated wheatgerm agglutinin and peanut agglutinin. Lectins such as Dolichos biflorus agglutinin, which binds only to mouse, Griffonia simplicifolia (GS-I), which binds to mouse and rat but not hamster and rabbit and soybean agglutinin, which binds only to rodents, reflect characteristic differences between phylogenetically related mammals.