RESUMO
PURPOSE: The effects of estradiol on oocyte development seem to be varied among species. The present study investigated the effects of 17ß-estradiol on in vitro maturation of buffalo and goat oocytes. METHODS: Cumulus oocyte complexes (COCs) were aspirated from large antral follicles of slaughtered buffalo and goat ovaries. COCs were cultured in TCM-199 medium supplemented with 0, 0.5, 1, and 1.5 µg/mL of 17ß-estradiol for in vitro maturation. Then, oocytes were used for the examination of state of nuclear maturation and cumulus expansion. RESULTS: In both species, oocytes treated with 17ß-estradiol showed higher cumulus expansion rate than control (0 µg/mL treated). In buffalo, the percentage of oocytes matured to the metaphase II (MII) stage increased in the concentration-dependent manner of 17ß-estradiol. Similarly, estradiol positively influenced nuclear maturation of goat oocytes in vitro. CONCLUSIONS: Estradiol has promoting effects on normalprogress of in vitro oocyte meiosis in buffalos and goats.
