Nuclear maturation inhibitors in Bufo arenarum oocytes

In Bufo arenarum, as in other amphibian species, nuclear maturation--characterized by germinal vesicle breakdown (GVBD) and meiosis resumption--is induced by progesterone. Seasonal variations in the sensitivity to progesterone were observed in Bufo arenarum oocytes. The gonadotropin FSH and drugs such as dbcAMP and xanthine did not affect nuclear maturation per se, although they acted as negative modulators of progesterone-induced nuclear maturation. Similar results to FSH in nuclear maturation were obtained with 17 beta-estradiol