title: Timing of sequential changes in chromosome configurations during the 1st meiotic division of pig oocytes cultured in vitro.
abstract: This study examines the timing of changes in chromosome configurations of pig oocytes derived from small antral follicles of follicular and/or inactive stage donors using modified 199 medium supplemented with gonadotropins (Follicle Stimulating Hormone (FSH), 10 IU/ml; Human Chorionic Gonadotropin (hCG), 10 IU/ml) and Glucosamine (0.539 mg/ml). Oocytes (n = 1,215) were fixed at the end of 3 hourly intervals from 0-48 hr of culture. Results were expressed as the percentage of oocytes at each stage of maturation for each time point. The germinal vesicle (GV) stage was observed for the first 17.6 hr; germinal vesicle breakdown (GVBD) stage between 17.6-26.4 hr; metaphase I (M-I) from 26.4-30.9 hr; anaphase I (A-I) ranged from 30.9-33.4 hr; telophase I (T-I) at 33.4-34.4 hr; and metaphase II (M-II) at 34.4-48 hr.
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: M B
authors.initials: MB
authors.lastname: Ocampo
authors.forename: L T
authors.initials: LT
authors.lastname: Ocampo
authors.forename: H
authors.initials: H
authors.lastname: Kanagawa
mesh_terms: D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D008540:Meiosis; D009865:Oocytes / Q000502:physiology*; D013552:Swine; D013997:Time Factors