They find a gene that could be key as a male contraceptive

A team of scientists from Washington State University (WSU) in the United States has identified a gene present in almost all mammalian species which could be key to developing a highly effective, reversible and non-hormonal male contraceptive.

In the study, the team identified the expression of the ‘Arrdc5’ gene, present in testicular tissue of mice, pigs, bovines, and humans which, when knocked out in mice, produced infertility only in males.

Details are published today in an article in Nature Communications.

“The study identifies for the first time that this gene is only expressed in testicular tissue, nowhere else in the body, and that it is expressed in multiple mammalian species,” said Jon Oatley, lead author and professor of molecular biosciences at the University of of washington.

“When this gene is inactivated or inhibited in males, they produce sperm that cannot fertilize an egg, a primary goal for the development of male contraceptives,” he explains.


Although other molecular targets have been identified for the potential development of male contraceptives, the ‘Arrdc5’ gene is specific to the male testis and is found in multiple species.

The lack of this gene causes a disease called oligoasthenoteratospermia or OAT, which affects the concentration, mobility and morphology of spermatozoa and prevents them from fertilizing eggs, thus causing infertility in men.

In the WSU study, heMale mice lacking this gene produced 28% fewer sperm, They moved 2.8 times slower than normal mice, and about 98% of their sperm had abnormal heads and midparts.

The protein encoded by this gene is necessary for normal sperm production, which is why Oatley’s team is already working on the design of a drug that inhibits the production or function of this protein, which would favor male contraception without interfering with the hormones.

And it is that, by altering only this proteintestosterone would not be affected, which is important, since, in addition to producing sperm, testosterone is also responsible for the formation of bone mass and muscle strength, and for the production of red blood cells.

Designing a drug targeting this protein it would also facilitate its reversibility as a contraceptive.

“It is not a question of eliminating the ability to produce sperm, but of preventing those that are produced from doing so correctly”, so “in theory, the drug could be withdrawn and the sperm would begin to be produced normally again”. reasons the researcher.

Oatley and the study’s first author, Mariana Giassetti, have filed a provisional patent for the development of a male contraceptive based on this gene and the protein it encodes. As the gene is found in almost all mammalian species, the finding also holds promise for its use in animals as an alternative to castration, which is currently one of the few existing ways to control reproduction.

Could also be used in wildlife when you want to limit the overpopulation of a species.

In humans, this drug would help control reproduction because while many forms of birth control exist for women, they are not always effective or widely available, and more than half of pregnancies worldwide remain unintended. according to the United Nations.

In the case of men, right now, there is no method of contraception other than surgery, “and only a small percentage of men opt for a vasectomy,” Oatley recalls. “If we can turn this discovery into a contraceptive solution, it could have far-reaching repercussions,” she concludes.