title: Development to the blastocyst stage of parthenogenetically activated in vitro matured porcine oocytes after solid surface vitrification (SSV).
abstract: The effects of solid surface vitrification (SSV) on viability and parthenogenetic development of in vitro matured (IVM) porcine oocytes was investigated in the present study. Cumulus-free IVM porcine oocytes were subjected either to SSV or SSV combined with a cytochalasin B (CB) pre-treatment (SSV+CB) or all steps of SSV but without cooling (toxicity control=TC; toxicity control with CB pre-treatment=TC+CB). Oocyte viability was evaluated by plasma membrane integrity and esterase activity measured by a combined staining with fluorescein diacetate, propidium iodide and Hoechst 33342. Surviving oocytes were parthenogenetically activated then cultured in vitro (IVC) for 6 days. The proportion of live oocytes after vitrification was significantly lower than that of the TC, TC+CB and the control groups, regardless of the CB pre-treatment. Treatment of oocytes with cryoprotectants did not decrease the rates of surviving oocytes. After activation of oocytes, the proportion of cleaved embryos was significantly higher in the SSV+CB (P<0.05) than that of the SSV group. Nevertheless, significantly more oocytes cleaved (P<0.05) in the TC, TC+CB and the control groups. On Day 6, the rate of blastocysts in the SSV and SSV+CB groups did not differ significantly. The number of oocytes developing to blastocyst and the mean number of blastomeres per embryo were significantly higher (P<0.05) in the TC, TC+CB and the control compared with that of the SSV and SSV+CB groups. To our knowledge, this is the first report on parthenogenetic development to blastocysts of porcine oocytes vitrified at the metaphase-II stage. Results indicate that the high concentrations of cryoprotectants were not harmful for in vitro development, and that CB pre-treatment may increase survival and development of SSV vitrified porcine oocytes.
authors.affiliation: Laboratory of Micromanipulation and Genetic Reprogramming, Institute of Animal Biology, Agricultural Biotechnology Center, Szent-Györgyi Albert u. 4, 2100 Gödöllö, Hungary. somek76@yahoo.com
authors.forename: Tamás
authors.initials: T
authors.lastname: Somfai
authors.forename: András
authors.initials: A
authors.lastname: Dinnyés
authors.forename: Dagmar
authors.initials: D
authors.lastname: Sage
authors.forename: Miklós
authors.initials: M
authors.lastname: Marosán
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Carnwath
authors.forename: Manabu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Heiner
authors.initials: H
authors.lastname: Niemann
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003571:Cytochalasin B / Q000494:pharmacology; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D013552:Swine / Q000196:embryology*
chemical_list: D003571:Cytochalasin B