Gene may allow non-hormone male contraception

The discovery of a gene essential for sperm maturation could eventually lead to development of non-hormonal male contraception, experts predict. They say it could also help in the search for a treatment for male infertility.

The gene Katnal1 is crucial for sperm to be able to mature, researchers report today in PLoS Genetics. Their work, in mice, showed that the gene is essential to control the breakdown and rebuilding of microtubules, which support and provide nutrients to developing sperm. Mice modified not to carry the gene were infertile.

The study’s authors, led from the University of Edinburgh, hope that if they could regulate the gene in men’s testes then sperm would be unable to mature fully, and thus rendered ineffective. This, they say, would provide an alternative to male contraceptives that work by disrupting hormone production, which can lead men to suffer mood swings, irritability and acne.

They say that their discovery could also prove important in the search for treatment for some cases of male infertility, when malfunction of the Katnal1 gene means that sperm do not properly develop.

Dr Lee Smith, reader in genetic endocrinology at the university’s Centre for Reproductive Health, said: “If we can find a way to target this gene in the testes, we could potentially develop a non-hormonal contraceptive.

“The important thing is that the effects of such a drug would be reversible because Katnal1 only affects sperm cells in the later stages of development, so it would not hinder the early stages of sperm production and the overall ability to produce sperm.”

He concluded: “Although other research is being carried out into non-hormonal male contraceptives, identification of a gene that controls sperm production in the way Katnal1 does is a unique and significant step forward in our understanding of testis biology.”