title: Changes in the distribution of lectin receptors during capacitation and acrosome reaction in boar spermatozoa.
abstract: Sperm glycocalyx modifications are known to occur during capacitation and the acrosome reaction (AR). These changes are very important for gamete recognition and fertilization in mammals but are not fully understood. The purpose of this study was to determine the distribution of surface carbohydrates in boar spermatozoa during capacitation and the AR. These processes may be associated with specific changes in the content and distribution of surface carbohydrates. Thirty-nine ejaculates from fertile boars of various breeds were analyzed. N-Acetylglucosamine and sialic acid, mannose and fucose residues were detected by fluorescence microscopy and flow cytometry using FITC-conjugated lectins. Triticum vulgaris agglutinin (WGA) bound on the head and tail of fresh sperm, and fluorescence intensity (FI) decreased in capacitated sperm (6751 to 5621 fluorescence units (FU), P<0.05), and decreased further in acrosome-reacted sperm (5240 FU, P<0.05). Concanavalia ensiformis agglutinin (Con-A) bound homogeneously on the head and the midpiece of fresh sperm with a FI of 5335 FU, and increased in capacitated sperm (5957 FU, P<0.05) mainly on the acrosomal region. In acrosome-reacted sperm, fluorescence was concentrated on the border of the acrosomal region (5608 FU, P<0.05). It was not possible to detect Ulex europaeus agglutinin (UEA) by fluorescence microscopy. However, flow cytometry revealed UEA receptors (187 FU), with a nonsignificant decreased number in capacitated (142 FU) and AR sperm (142 FU). Labeling patterns were similar in all breeds. Sperm glycocalyx modifications observed in this study provide insights to the molecular modifications accompanying capacitation and the AR. This kind of study could improve the diagnosis of reproductive problems of subfertile boars and males of other species.
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Apdo Postal 55-535, México D F CP 09340, Mexico.
authors.forename: Irma
authors.initials: I
authors.lastname: Jiménez
authors.forename: Humberto
authors.initials: H
authors.lastname: González-Márquez
authors.forename: Rocío
authors.initials: R
authors.lastname: Ortiz
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Herrera
authors.forename: Adelfa
authors.initials: A
authors.lastname: Garcií
authors.forename: Miguel
authors.initials: M
authors.lastname: Betancourt
authors.forename: Reyna
authors.initials: R
authors.lastname: Fierro
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D020101:Acrosome Reaction / Q000502:physiology*; D000818:Animals; D003208:Concanavalin A / Q000378:metabolism; D005434:Flow Cytometry / Q000662:veterinary; D005643:Fucose / Q000378:metabolism; D019276:Glycocalyx / Q000502:physiology; D008297:Male; D008358:Mannose / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000662:veterinary; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D037121:Plant Lectins / Q000378:metabolism; D011975:Receptors, Mitogen / Q000378:metabolism*; D013075:Sperm Capacitation / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology*; D013552:Swine / Q000502:physiology*; D014909:Wheat Germ Agglutinins / Q000378:metabolism
chemical_list: D037121:Plant Lectins; D011975:Receptors, Mitogen; C036850:Ulex europaeus lectins; D014909:Wheat Germ Agglutinins; D003208:Concanavalin A; D005643:Fucose; D019158:N-Acetylneuraminic Acid; D008358:Mannose; D000117:Acetylglucosamine