title: Binding of rainbow trout sperm to egg is mediated by strong carbohydrate-to-carbohydrate interaction between (KDN)GM3 (deaminated neuraminyl ganglioside) and Gg3-like epitope.
abstract: KDNalpha2-->3Galbeta4Glcbeta1Cer [(KDN)GM3] is a major (approximately 90%) component of total gangliosides found in sperm of rainbow trout (Oncorhynchus mykiss) and was shown to be present prominently at the sperm head by immunochemical staining with its specific mAb kdn3G. Liposomes containing (KDN)GM3 adhere specifically to GalNAcbeta4Galbeta4Glcbeta1Cer (Gg3Cer)-coated plastic plates. Interaction between (KDN)GM3 and Gg3Cer was much stronger than that previously observed between Neu5Acalpha2-->3Galbeta4Glcbeta1Cer and Gg3Cer. (KDN)GM3-Gg3Cer interaction did not require the presence of Ca2+ and Mg2+, but was enhanced in the presence of Mn2+. Fresh trout sperm adhered specifically to Gg3Cer-coated plates under physiological conditions, and the binding was inhibited by pretreatment of sperm with mAb kdn3G. The presence of Gg3 or Gg3-related epitope structure in the specific area surrounding the micropyle, through which sperm enter the egg, was confirmed by immunogold labeling under electron microscopy. These findings suggest that initial sperm-egg adhesion during the process of fertilization occurs when sperm adhere to the area surrounding the micropyle through specific interaction between (KDN)GM3 on the sperm head and Gg3 epitope (GalNAcbeta4Galbeta1-->) expressed at a defined region of the egg surface membrane.
authors.affiliation: Division of Biomembrane Research, Pacific Northwest Research Institute, Seattle, WA 98122, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Yu
authors.forename: Naoya
authors.initials: N
authors.lastname: Kojima
authors.forename: Sen-itiroh
authors.initials: SI
authors.lastname: Hakomori
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Kudo
authors.forename: Sadako
authors.initials: S
authors.lastname: Inoue
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002413:Cations, Divalent; D002448:Cell Adhesion; D002458:Cell Fractionation; D018985:Epitopes, B-Lymphocyte / Q000378:metabolism; D005260:Female; D005679:G(M3) Ganglioside / Q000378:metabolism*; D006028:Glycosphingolipids / Q000378:metabolism*; D008081:Liposomes; D008297:Male; D016253:Microscopy, Immunoelectron / Q000379:methods; D017686:Oncorhynchus mykiss; D010063:Ovum / Q000378:metabolism*; D013077:Sperm Head / Q000378:metabolism; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*; D014020:Tissue Extracts; D014817:Vitelline Membrane / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D002413:Cations, Divalent; D018985:Epitopes, B-Lymphocyte; D005679:G(M3) Ganglioside; D006028:Glycosphingolipids; D008081:Liposomes; D014020:Tissue Extracts