Structural analysis of 20 oligosaccharide-alditols released from the jellycoat of Rana palustris eggs by reductive beta-elimination - Characterization of the polymerized sequence [Gal(beta 1,3)GalNAc(alpha 1-4)]n

The eggs of amphibians are surrounded by three to eight layers of jelly coa ts. This extracellular matrix is mainly composed of hydrated mucin-type gly coproteins. These highly glycosylated molecules are synthesized by oviduct and play an important role in the fertilization process. Recent structural analyses have shown the strict species-specificity of the O-linked oligosaccharides which constitute 60-70% of these oviducal mucins . Consequently, these carbohydrate chains represent new phenotypic markers, and from a biological point of view, can influence parasite tropism or can be involved in species-specific interaction of gametes. The primary structure of 20 oligosaccharide-alditols, released by alkali/bo rohydride treatment from the mucin of Rana palustris egg jelly coats, was e stablished by H-1 and C-13-NMR analysis. Thirteen of these components posse ss new structures and the polymerization of the sequence Gal(beta 1-3)GalNA c(alpha 1-4) characterizes the species-specificity of R. palustris.