title: Elevated NaCl concentration improves cryotolerance and developmental competence of porcine oocytes.
abstract: High hydrostatic pressure has been reported to improve the fertilizing or developmental ability of mammalian spermatozoa, oocytes and embryos. This study investigated the effect of another stress, temporarily increased NaCl concentration, on cryotolerance and developmental competence of porcine oocytes. In Experiment 1, survival rates were compared after 1 h exposure to seven elevated NaCl concentrations and 1 h recovery time. In Experiment 2, oocytes were exposed to 593 and 1306 mOsmol NaCl, subsequently recovered, vitrified, then subjected to parthenogenetic activation. Both cleavage and blastocyst rates increased after NaCl treatment compared with untreated controls. In Experiment 3, oocytes were treated with 593 mOsmol NaCl followed by 1 and 2 h recovery, respectively, then used as recipients for somatic cell nuclear transfer (SCNT). Cleavage rates were not different from those in untreated controls, but blastocyst rates increased in both NaCl-treated groups. In conclusion, treatment of porcine oocytes with elevated NaCl concentrations improved their developmental competence after vitrification and parthenogenetic activation or SCNT. Further experiments are required to investigate in-vivo consequences, and the effect on gametes and embryos of different mammalian species.
authors.affiliation: Population Genetics and Embryology, Institute of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, DK-8830 Tjele, Denmark. Lin.Lin@agrsci.dk
authors.forename: Lin
authors.initials: L
authors.lastname: Lin
authors.forename: Yutao
authors.initials: Y
authors.lastname: Du
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kragh
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Stig
authors.initials: S
authors.lastname: Purup
authors.forename: Masashige
authors.initials: M
authors.lastname: Kuwayama
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Zhang
authors.forename: Huanming
authors.initials: H
authors.lastname: Yang
authors.forename: Lars
authors.initials: L
authors.lastname: Bolund
authors.forename: Gábor
authors.initials: G
authors.lastname: Vajta
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D015925:Cryopreservation; D005260:Female; D009865:Oocytes / Q000166:cytology*; D010312:Parthenogenesis; D012965:Sodium Chloride / Q000378:metabolism*; D013552:Swine
chemical_list: D012965:Sodium Chloride