Histochemical detection of the lectin-binding carbohydrates in the zona pellucida during oocyte growth in the wild boar (Sus scrofa scrofa)

The changes that occur in the carbohydrate composition of zona pellucida glycoproteins during oocyte maturation in the wild-boar were studied using periodic-acid Schiff (PAS), High Iron Diamine (HID) and Low Iron Diamine (LID). Lectin staining was performed with a panel of 11 HRP-lectin conjugates combined with neuraminidase digestion and chemical treatments. There were few internal glucidic residues, such as N-acetylglucosamine, in the wild boar zona pellucida but there were many subterminal beta-N-acetylgalactosamine, alpha- and beta-galactose determinants masked by sialic acid. In addition, beta-N-acetylgalactosamine, beta-galactose-(1-3)-N-acetylgalactosamine and beta-galactose-(1-4)-N-acetylglucosamine were detected in the sulphated form in the terminal and/or subterminal position. Some differences in the lectin reactive sites occurred in the zona pellucida, depending on the stage of oocyte maturation