Progesterone Receptor Action in Sperm and Other Tissues (image) University of California - Berkeley Share Print E-Mail Caption Progesterone, a sex hormone involved in all aspects of female fertility, also primes sperm make the final push toward fertilizing the egg. UC Berkeley researchers have discovered the receptor -- the protein ABHD2 -- that responds to progesterone on sperm cells and initiates the power kick of the sperm's tail that propels it into the egg. This receptor is found in many other tissues, and may be the key relay in progesterone's actions on nerve cells, smooth muscle and lung tissue. Credit Polina Lishko and Melissa Miller, UC Berkeley Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.