Maturation of oocytes from normal and atretic equine ovarian follicles as affected by steroid concentrations.
The ovaries of 23 mares were collected at slaughter during April-June and follicles (4-40 mm in diameter) were dissected and punctured to obtain oocytes for culture. The follicles were grouped according to histology: (a) normal, (b) showing primary and (c) secondary atresia. Antral fluid was analyzed for steroid content; oestradiol and testosterone (but not progesterone or androstenediol) were closely correlated with follicle size and histological state. Oocytes were cultured early after slaughter in Medium 199 (Difco OSI, France) or Medium B2, the highest percentage of oocytes reaching Metaphase 2 (53%) occurred after 36-38 h in culture. Among the 52 oocytes cultured and inseminated 1 case was confirmed with a 4-blastomere-like structure, 10 cases had structures resembling pronuclei, 9 oocytes were in Metaphase 1, 14 were in Metaphase 2 and 18 were degenerated.
Okolski
A
A
Academy of Agriculture, Cracow, Poland.
Bézard
J
J
Magistrini
M
M
Palmer
E
E
D000735:Androstenedione / Q000032:analysis; D000818:Animals; D001826:Body Fluids / Q000737:chemistry; D003470:Culture Media; D004958:Estradiol / Q000032:analysis; D005260:Female; D005496:Follicular Atresia / Q000502:physiology*; D006107:Granulosa Cells / Q000166:cytology; D006736:Horses / Q000502:physiology*; D009865:Oocytes / Q000502:physiology*; D011374:Progesterone / Q000032:analysis; D013739:Testosterone / Q000032:analysis
D003470:Culture Media; D013739:Testosterone; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol