FLICKR, ZAPPYS TECHNOLOGY SOLUTIONSResearchers have identified a sperm-specific protein, essential for fertilization, that is negatively affected by US Food and Drug Administration–approved drugs in male mice. The results, which the authors contend show promise for a male contraceptive, were published last week (October 1) in Science.
Researchers from Osaka University and Tsukuba University in Japan focused on the calcineurin protein, which exists in multiple forms throughout the body. They followed previous lines of evidence indicating that sperm produce a specific form of calcineurin.
The team created a set of knockout mice that lacked the sperm-specific form of the enzyme and observed the animals’ sexual activity. While the knockout males were able to ejaculate normally, they failed to impregnate any of the normal female mice in the study. Analyzing the semen, the researchers discovered that the midsection of the sperm cells’ flagella were too rigid to help the sperm fully penetrate and fertilize the eggs.
The researchers then gave normal mice a set of calcineurin-inhibiting medications. Over a five-day course of drug ...
