title: The relationship between antral follicle count in a bovine ovary and developmental competence of in vitro-grown oocytes derived from early antral follicles.
abstract: To clarify the relationship between ovarian reserve and the developmental competence of bovine oocytes, oocyte-granulosa complexes (OGCs) collected from early antral follicles (≤ 1 mm) in ovaries with high (≥ 25) and low (<25) antral follicle counts (AFCs) were used. OGCs derived from different AFC groups were cultured for growth followed by maturation, fertilization and blastocyst formation. Viability of OGCs during growth culture was similar between groups; however, OGCs in the high-AFC group had a larger number of granulosa cells than the low-AFC group at 12 days of growth. The proportion of matured oocytes in the high-AFC group was higher than that in the low-AFC group. Mitochondrial activity of oocytes before maturation in the high-AFC group was higher than that in the low-AFC group; however, accumulation of reactive oxygen species was similar between groups. Cleavage rate in the high-AFC group tended to be higher than that in the low-AFC group, although blastocyst development was similar between groups. In conclusion, oocytes derived from ovaries with high AFC have higher maturational ability and fertilizability than those from low AFC. The difference may be caused by high proliferation of granulosa cells from ovaries with high AFC.
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Nagai
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Katagiri
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagano
mesh_terms: D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D002470:Cell Survival; D005260:Female; D005307:Fertilization in Vitro; D006107:Granulosa Cells / Q000166:cytology; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology* / Q000378:metabolism; D010053:Ovary / Q000166:cytology* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species