| The induction of oocyte maturation by specific progestins in fish and amphibian species is one of the most well studied nongenomic actions of steroid hormones. However, the specific progestin receptors involved and the signaling mechanisms leading to final oocyte maturation have been a subject of debate. Previous research suggests a nongenomic role of the nuclear progestin receptor (nPR) and two isoforms of membrane progestin receptors (mPRα and mPRβ) in the induction of oocyte maturation. Herein, we studied both nPR and mPRs (mPRα and mPRβ) in zebrafish, and examined the role of these receptors in the induction of oocyte maturation in order to: (1) determine the receptor that mediates nongenomic progestin actions; (2) characterize nongenomic progestin signaling mechanisms leading to oocyte maturation; and (3) establish zebrafish as a model for the study of nongenomic progestin actions. |
