title: In vitro fertilization and cleavage capability of bovine follicular oocytes classified by cumulus cells and matured in vitro.
abstract: Bovine oocytes were collected from ovaries obtained from an abattoir. They were classified according to the character of the cumulus cells using a stereomicroscope, and cultured in 25 mM Hepes buffered Tissue Culture Medium 199 supplemented with 10% fetal calf serum at 39 degrees C and inseminated by capacitated sperm. Maturation rates of Class A oocytes, with compact, dense cumulus cells; Class B, partially naked oocytes with thin cumulus layers or small remnants of cumulus cells and Class C, naked oocytes were 97.4% (38/39), 89.8% (106/118) and 52.9% (45/85), respectively. The fertilization rates for the three classes were 86.8%, 85.8% and 53.3%, respectively. The naked oocytes had a significantly lower fertilization rate than oocytes of the other two classes. Significantly more Class A oocytes cleaved (63.7%, 232/364) than those of Class B (29.5%, 36/122) and Class C (17.7%, 28/158).
authors.affiliation: National Institute of Animal Industry Tsukuba Norindanchi P.O. Box 5, Ibaraki, Japan 305.
authors.forename: Y
authors.initials: Y
authors.lastname: Shioya
authors.forename: M
authors.initials: M
authors.lastname: Kuwayama
authors.forename: M
authors.initials: M
authors.lastname: Fukushima
authors.forename: S
authors.initials: S
authors.lastname: Iwasaki
authors.forename: A
authors.initials: A
authors.lastname: Hanada