title: Induction of acrosomal exocytosis in chicken spermatozoa by inner perivitelline-derived N-linked glycans.
abstract: In birds, the ovum is surrounded by a glycoprotein coat known as the inner perivitelline layer (IPVL), which is analogous to the mammalian zona pellucida and, as such, is the site of initial sperm binding and induction of acrosomal exocytosis (the acrosome reaction). In this study, we demonstrate that oligosaccharides isolated from chicken-IPVL glycoproteins are capable of inducing the acrosome reaction in chicken spermatozoa. Preparations containing only O-linked glycans were unable to induce the acrosome reaction whereas N-linked oligosaccharides released from the IPVL by PNGaseF treatment could induce the acrosome reaction. Addition of galactose to terminal N-acetyglucosamine residues suppressed the acrosome reaction-inducing capacity of the oligosaccharide preparation; however, this capacity could be restored by co-incubation with beta-galactosidase. This evidence suggests that the acrosome reaction-inducing factor is probably an N-linked oligosaccharide with terminal N-acetyl-glucosamine residues.
authors.affiliation: Avian Reproduction Group, Division of Molecular and Life Sciences, School of Science and Engineering, University of Abertay Dundee, Bell Street, Dundee, DD1 1HG, Scotland, United Kingdom.
authors.forename: A J
authors.initials: AJ
authors.lastname: Horrocks
authors.forename: S
authors.initials: S
authors.lastname: Stewart
authors.forename: L
authors.initials: L
authors.lastname: Jackson
authors.forename: G J
authors.initials: GJ
authors.lastname: Wishart
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry; D020101:Acrosome Reaction; D000581:Amidohydrolases / Q000494:pharmacology; D000818:Animals; D002645:Chickens; D002846:Chromatography, Affinity; D005089:Exocytosis; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D008297:Male; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology*; D014817:Vitelline Membrane / Q000737:chemistry / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D009844:Oligosaccharides; D011134:Polysaccharides; D001616:beta-Galactosidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D016650:Fluorescein-5-isothiocyanate; D000117:Acetylglucosamine; D005690:Galactose