Species differences in the lectin-binding sites on the zona pellucida of rodent eggs.

zona pellucida contains receptors for a variety of plant lectins, glycoproteins that bind to specific saccharide determinants (Oikawa, Yanagimachi & Nicol¬ son, 1973; Oikawa, Nicolson & Yanagimachi, 1974; Nicolson, Yanagimachi & Yanagimachi, 1975). Some of these lectins can bind to the zona pellucida and induce egg agglutination and/or cause changes in the ability of the exterior region of the zona to scatter visible light (Oikawa et al., 1973, 1974; Oikawa, Nicolson & Yanagimachi, 1975). We report here that rodent eggs show speciesspecific differences in lectin-induced agglutination and light scattering proper¬ ties of their zonae pellucidae when treated with Ricinus communis agglutinin I (RCAi), which recognizes /?-linked D-galactose residues (Nicolson & Blaustein, 1972; Nicolson & Lacorbier, 1973), or wheat germ agglutinin (WGA), which recognizes N-acetyl-D-glucosamine and sialic acid residues (Burger & Goldburg, 1967; Greenaway & LeVine, 1973). Unfertilized eggs of the golden hamster, rat (Fisher) and mouse (Swiss albino)