Japanese scientists have reported a potential breakthrough in the study of male infertility after they identified the role a certain protein plays in the motility of sperm.
Researchers from Osaka University and Tsukuba University examined sperm calcineurin in mice and found that the protein is essential for spermatozoa to find their way to an egg.
The research was published Thursday in the online version of Science, a United States-based research journal.
Calcineurin exists in human sperm, and the findings may be important in the study of infertility. Furthermore, they said, inhibiting the substance could lead to a reversible form of contraception for men.
"By temporarily weakening its functions, there is potential for developing birth control pills for men," said Masahito Ikawa, a professor of reproductive biology at Osaka University, who led the study.
Calcineurin is found throughout the bodies of mice and humans, where it generally functions to activate the immune system. The researchers specified a type that is only found in sperm.
The team produced a mouse that was unable to generate sperm calcineurin and found that its sperm could not bend their tails or force their way through the jelly coat surrounding the egg of a female mouse.
The team also administered a calcineurin inhibitor to male mice. They found that sperm tails gradually lost their mobility, and females the mice mated with did not become pregnant. The male mouse recovered its ability to conceive about a week after the treatment was halted.