title: Optimizing electrical activation of porcine oocytes by adjusting pre- and post-activation mannitol exposure times.
abstract: Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre- and post-activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre- or post-electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation showed significantly higher blastocyst development than 0 min pre- and 0 min post-activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre- and 0 min post-activation. In conclusion, exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre- and 3 min post-activation.
authors.affiliation: Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors.forename: D
authors.initials: D
authors.lastname: Kwon
authors.forename: I M
authors.initials: IM
authors.lastname: Saadeldin
authors.forename: S J
authors.initials: SJ
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Park
authors.forename: J T
authors.initials: JT
authors.lastname: Kang
authors.forename: H J
authors.initials: HJ
authors.lastname: Park
authors.forename: J H
authors.initials: JH
authors.lastname: Moon
authors.forename: O J
authors.initials: OJ
authors.lastname: Koo
authors.forename: G
authors.initials: G
authors.lastname: Jang
authors.forename: B C
authors.initials: BC
authors.lastname: Lee
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D008353:Mannitol / Q000494:pharmacology*; D009865:Oocytes / Q000502:physiology*; D010312:Parthenogenesis / Q000502:physiology; D013552:Swine; D013997:Time Factors
chemical_list: D008353:Mannitol