Male mice lacking CatSper are completely infertile. Their sperm move sluggishly (at approximately one third of the normal rate) and can fertilize eggs only if the eggs have been stripped of their protective coat of zona pellucida.
Based on these data, says David Garbers (University of Texas Southwestern Medical Center, Dallas, TX), a CatSper inhibitor might be useful as a male contraceptive. “The problem with going after a male contraceptive is that you have millions of sperm and you have to get them all,” he says. “Amazingly enough, when this channel was gone they got no fertilization. That makes it reasonably attractive as a drug target.” ▪