Protein Clue for Male Contraceptive
Male Mice Lacking a Certain Protein Are Infertile, Lab Tests Show
Nov. 1, 2006 -- The hunt for a male contraceptive pill may have a new target: a protein called Gba2.
Male mice lacking that protein are infertile, scientists report in The Journal of Clinical Investigation.
Curbing Gba2 might serve as a male contraceptive, the researchers suggest.
They included David Russell, PhD, of the molecular genetics department at the University of Texas Southwestern Medical Center in Dallas.
Russell's team didn't try to make a male contraceptive pill. Instead, they studied male and female mice, some of which lacked the gene that makes Gba2.
The female mice without Gba2 were fertile. But the male mice without that protein were infertile.
Those male mice had sperm with "abnormally large, round heads" that didn't swim very well, the researchers write.
But the researchers still have a lot to learn about Gba2 in people.
Russell's team checked the genes of men whose sperm had the same unusual head shape. Those men, who came from three unrelated families, had no mutations in their Gba2 gene.
That finding may mean that Gba2 isn't always responsible for that particular sperm condition in men, but further studies are needed in other affected men, the researchers note.
Journal editorialists note that male mice have more Gba2 in their testes than men do.
Whether or not blocking Gba2 with a drug would have a contraceptive effect in men "remains an open question," write the editorialists.
They included Martin Matzuk, MD, PhD, a professor at Baylor College of Medicine in Houston.