Reproduction is a complicated physiological event that requires precise hormonal control. Gametogenesis is mainly regulated by hormones produced by the brain‑pituitary‑gonadal axis. During pregnancy, the placenta produces a large number of hormones which profoundly influence the initiation, maintenance, and termination of pregnancy. Understanding how reproductive function is regulated by hormones has made significant contributions to human reproductive health. Hormones and their synthetic analogs have been used to promote or suppress reproduction, from contraception to treatment of infertility.

Research in our laboratory is focused on the role of activin and transforming growth factor beta (TGF‑beta) in female reproduction. Using zebrafish as a model, we are studying the structure of activin and TGF‑beta and how they regulate ovarian functions, especially oocyte maturation. We are also investigating the role of activin and TGF‑beta in human pregnancy. We have shown that activin stimulates, while TGF‑beta inhibits, progesterone and estradiol production. The cellular and molecular mechanism of activin and TGF‑beta actions are currently under examination. Coordinated actions of progesterone and estradiol are critical for all stages of pregnancy, from implantation to delivery of a healthy newborn. Therefore, we hypothesize that by exerting opposite effects on steroid production, activin and TGF‑beta play a physiological role in controlling the normal progression of pregnancy.