Estrogen is produced in in the germ cells of the testis and sperm in the epididymis of male.It regulates fluid reabsorption in the efferent ductules. It is important for the uptake of water, ions and proteins from the fluid that carries the sperm. The efferent ductules are responsible for reabsorbing nearly 90 percent of the water from this fluid. Without the reabsorption, the sperm remain diluted and therefore incapable of normal maturation in the epididymis