title: Cytochemical and biochemical evidences for a complex tridimensional structure of the hamster zona pellucida.
abstract: Zona pellucida (ZP) is an extracellular matrix that surrounds eggs and pre-implantation embryos and is required for in vivo fertility. A key event in successful fertilization is sperm binding to the surface of the ZP. It has been previously described that the hamster sperm binds mainly the outer region of the ZP which corresponds to the porous region in contact with the cumulus cells. Using ultrastructural cytochemistry approaches with an antibody developed against porcine ZP, this study shows that the pig ZP shares epitopes with some rodent species like hamster, rat and mouse. In the hamster, these epitopes are located mainly in the outer region of the ZP of preovulatory and ovulated oocytes. By means of biochemical approaches it was demonstrated that 1) the antibody is specific for the native hamster ZP3, 2) four different bands with a molecular weight of 67, 60, 48 and 38 kDa after N-linked deglycosylation suggesting that the hamster ZP is formed by four proteins, and 3) the different composition observed in the outer region of the hamster ZP could be due to a specific supramolecular structure that makes some epitopes accessible for the antibodies. In summary, this study provides evidence that the different composition observed in the different regions of the ZP is mediated by a different organization of the components of the ZP produced during the oocyte maturation. This different organization could be responsible for the different sperm binding affinity observed for sperm to the outer region versus the inner region of the ZP.
authors.affiliation: Department of Cell Biology and Histology, School of Medicine, University of Murcia, Murcia, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Jiménez-Movilla
authors.forename: Emma
authors.initials: E
authors.lastname: Martínez-Alonso
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Castells
authors.forename: María José
authors.initials: MJ
authors.lastname: Izquierdo-Rico
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Saavedra
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gutiérrez-Gallego
authors.forename: Richard
authors.initials: R
authors.lastname: Fayrer-Hosken
authors.forename: José
authors.initials: J
authors.lastname: Ballesta
authors.forename: Manuel
authors.initials: M
authors.lastname: Avilés
mesh_terms: D000818:Animals; D006224:Cricetinae; D004527:Egg Proteins / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006651:Histocytochemistry; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism; D008647:Mesocricetus; D051379:Mice; D016253:Microscopy, Immunoelectron; D009865:Oocytes / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000302:isolation & purification / Q000378:metabolism; D013045:Species Specificity; D034421:Sus scrofa; D015044:Zona Pellucida / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D000072216:Zona Pellucida Glycoproteins
chemical_list: D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins; C000606521:Zp3 protein, mouse