HQ Team
April 18, 2023: US scientists have filed for a provisional patent for developing a male contraceptive drug based on a gene and the protein it encodes.
According to a statement, researchers at Washington State University identified gene expression, Arrdc5, in the testicular tissue of mice, pigs, cattle, and humans.
The discovery of the gene in multiple mammalian species could pave the way for a highly effective, reversible, and non-hormonal male contraceptive for humans and animals.
When the scientists knocked out the gene in mice, it created infertility only in the males, impacting their sperm count, movement, and shape.
Jon Oatley, senior author, professor in WSU’s School of Molecular Biosciences, and the study’s first author Mariana Giassetti have filed a provisional patent for developing a drug based on their findings.
“The study identifies this gene for the first time as being expressed only in testicular tissue, nowhere else in the body, and multiple mammalian species express it,” said Mr Oatley.
Sperm can’t fertilize
“When this gene is inactivated or inhibited in males, they make sperm that cannot fertilize an egg, and that’s a prime target for male contraceptive development.”
While other molecular targets have been identified for potential male contraceptive development, the Arrdc5 gene is specific to the male testes and found in multiple species.
The lack of the gene also causes significant infertility, creating a condition called oligoasthenoteratospermia or OAT.
The condition, the most common diagnosis for human male infertility, shows decreased sperm production, slowed mobility, and distorted shape so the sperm cannot fuse with an egg.
In the study, the male mice lacking this gene produced 28% less sperm that moved 2.8 times slower than in normal mice – and about 98% of their sperm had abnormal heads and mid-pieces.
The study indicated that the protein encoded by this gene was required for normal sperm production.
Easily reversible
Mr Oatley’s team will next work on designing a drug that would inhibit the production or function of that protein.
Disrupting this protein wouldn’t require hormonal interference, a key hurdle in male contraception since testosterone plays other roles beyond sperm production in men, including building bone mass and muscle strength and red blood cell production.
Designing a drug to target this protein would also make it easily reversible as a contraceptive.
“You don’t want to wipe out the ability to ever make sperm – just stop the sperm being made from being made correctly,” he said. “Then, in theory, you could remove the drug, and the sperm would start being built normally again.”
As the gene is found across mammalian species, this knowledge also holds promise for use in animals, Oatley said. “This opens the potential to develop male contraception for use in livestock, perhaps replacing castration in some instances as a way to control reproduction, and in wildlife when managers seek to limit overpopulation of a species.”
Vasectomies
The initial focus, however, is on giving humans more control over their reproduction.
While there are many forms of birth control for women are not always effective or widely available, and more than half of pregnancies worldwide are still unintended, according to the United Nations.
“Developing a way to curb population growth and stop unwanted pregnancies is important for the future of the human race,” said Oatley.
“Right now, we don’t have anything on the male side for contraception other than surgery, and only a small percentage of men choose vasectomies. If we can develop this discovery into a solution for contraception, it could have far-ranging impacts.”
