Calcium signaling in sperm: help from prostasomes.

Mammalian sperm cells are equipped with sophisticated Ca2+ signaling mechanisms that are fundamental to sperm's success in fertilization. Unlike most other cells, however, mature sperm generally do not have the luxury of synthesizing new proteins. New evidence indicates that human sperm have a very clever way to solve the conflict between the critical demand for Ca2+ signaling tools and the silence of protein translation. Just before encountering the female reproductive tract, sperm acquire some of the key molecules for Ca2+ signaling from the male reproductive tract itself: prostasomes secreted by the prostate gland.