The effect of ruthenium red and Concanavalin A on the vitelline surface of fertilized and unfertilized rabbit ova.

Fertilized and unfertilized rabbit ova exposed to ruthenium red with the zona intact or after mechanical removal, for the demonstration of mucopolysaccharides on the surface coat. Ova were also exposed to Concanavalin A. Ruthenium red bound strongly to elements of the zona and increased the opacity of the plasmalemma. There was no notable change in staining of the vitellus following fertilization. Although there were ruthenium red stained bodies resembling cortical granules in crypts in the plasmalemma, there was no evidence for cortical granule extrusion of mucopolysaccharides. The Concanavalin reaction was seen over both unfertilized and fertilized ova, demonstrating receptors for terminal alpha-D-mannopyranosyl, alpha-D-glycopyranosyl, beta-D-fructofuranyosyl residues. The deposit on the fertilized egg surface was enormously enhanced indicating a change in the distribution of receptor sites.