title: Mitochondrial activity during pre-maturational culture in in vitro-grown bovine oocytes is related to maturational and developmental competences.
abstract: The objective of this study was to investigate the dynamics of mitochondrial activity in in vitro-grown (IVG) bovine oocytes during pre-maturational culture (pre-IVM) and its relationship to their developmental competence upon being subjected to different pre-IVM durations. After 12-day IVG culture, oocytes were cultured for 0, 10 or 20h with 3-isobutyl-1-methylxanthine (IBMX) as pre-IVM. Mitochondrial activity in IVG oocytes after 10h pre-IVM was the highest among all the pre-IVM durations (P<0.05). In addition, cleavage (79.4%) and blastocyst rates (38.9%) of embryos derived from IVG oocytes with 10h pre-IVM were higher than those with 20h pre-IVM (63.0 and 25.8%, respectively; P<0.05) and similar to those of in vivo-grown oocytes (82.7 and 36.7%, respectively). To confirm the developmental ability of IVG oocytes with 10h pre-IVM beyond the blastocyst stage in vivo, embryo transfer was attempted. Transferred embryos developed to the elongated embryonic stage (63.6%, 7/11) in the recipient uterus at Day 16 of oestrus, and a male calf was delivered (50%, 1/2). In conclusion, it was indicated that the mitochondrial activity of bovine IVG oocytes peaked at 10h pre-IVM and was closely correlated with the nuclear maturation and developmental competences of IVG oocytes.
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Weiping
authors.initials: W
authors.lastname: Huang
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Sung-Sik
authors.initials: SS
authors.lastname: Kang
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Nagai
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Yanagawa
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagano
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D059471:In Vitro Oocyte Maturation Techniques; D050498:Live Birth; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D011247:Pregnancy; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
chemical_list: D017382:Reactive Oxygen Species