title: Aquaglyceroporins 3 and 7 in bull spermatozoa: identification, localisation and their relationship with sperm cryotolerance.
abstract: The present study aimed to determine the localisation of aquaglyceroporins 3 (AQP3) and 7 (AQP7) in bull spermatozoa and their relationship with the sperm cell's resilience to withstand cryopreservation (i.e. cryotolerance). A total of 18 bull ejaculates were cryopreserved and their sperm quality analysed before and after freeze-thawing. The presence and localisation of AQP3 and AQP7 was determined through immunoblotting and immunocytochemistry. AQP3 was found in the mid-piece and AQP7 in the mid-piece and post-acrosomal region of bull spermatozoa. Immunoblotting showed specific signal bands at 30 and 60kDa for AQP3 and at 25kDa for AQP7. Neither the relative abundance of AQP3 and AQP7 nor their localisation patterns was altered by cryopreservation but individual differences between bull ejaculates were found in immunoblots. In order to determine whether these individual differences were related to sperm cryotolerance, bull ejaculates were classified as having good (GFE) or poor freezability (PFE) on the basis of their sperm quality after thawing. While the relative abundance of AQP3 before cryopreservation did not differ between ejaculates with GFE and PFE, the abundance of AQP7 was higher in GFE than in PFE ejaculates. This finding was further confirmed through principal component and linear regression analyses. In conclusion, the relative abundance of AQP7 in fresh semen may be used as a marker to predict bull sperm cryotolerance.
authors.affiliation: Department of Biology, Institute of Food and Agricultural Technology, University of Girona, C/ Maria Aurèlia Campany 65, Campus Montilivi, E-17071 Girona, Spain.
authors.forename: Noelia
authors.initials: N
authors.lastname: Prieto-Martínez
authors.affiliation: Department of Biology, Institute of Food and Agricultural Technology, University of Girona, C/ Maria Aurèlia Campany 65, Campus Montilivi, E-17071 Girona, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Morató
authors.affiliation: Department of Animal Pathology, University of Santiago de Compostela, Avda. Carballo Calero s/n, E-27002 Lugo, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Muiño
authors.affiliation: Department of Animal Selection and Reproduction, The Regional Agri-Food Research and Development Service of Asturias (SERIDA), Camin de Rioseco 1225, La Olla, Deva, E-33394 Gijón, Spain.
authors.forename: Carlos O
authors.initials: CO
authors.lastname: Hidalgo
authors.affiliation: Department of Animal Medicine and Surgery, Autonomous University of Barcelona, Building V, Campus Bellaterra s/n, E-08193 Bellaterra (Barcelona), Spain.
authors.forename: Joan E
authors.initials: JE
authors.lastname: Rodríguez-Gil
authors.affiliation: Department of Biology, Institute of Food and Agricultural Technology, University of Girona, C/ Maria Aurèlia Campany 65, Campus Montilivi, E-17071 Girona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Bonet
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women's Centre, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
authors.forename: Marc
authors.initials: M
authors.lastname: Yeste
mesh_terms: D000177:Acrosome / Q000502:physiology; D020101:Acrosome Reaction; D000818:Animals; D017849:Animals, Inbred Strains; D051397:Aquaglyceroporins / Q000737:chemistry / Q000378:metabolism*; D051400:Aquaporin 3 / Q000737:chemistry / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002417:Cattle; D002470:Cell Survival; D015925:Cryopreservation / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D016014:Linear Models; D008297:Male; D018613:Microscopy, Confocal; D008970:Molecular Weight; D025341:Principal Component Analysis; D021381:Protein Transport; D015203:Reproducibility of Results; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation / Q000009:adverse effects / Q000662:veterinary*; D032961:Sperm Midpiece / Q000502:physiology; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*
chemical_list: D051397:Aquaglyceroporins; D015415:Biomarkers; D051400:Aquaporin 3