Sperm-production gene could hold the key to developing a male pill

A non-hormonal male contraceptive pill could be developed by blocking a newly identified gene involved in the final stages of sperm production, according to scientists.

The gene, Katnal1, produces a protein, called katanin, which is active in Sertoli cells, a specialised population of cells in the testes that provide growing sperm with nutrients. The researchers, from the MRC Centre for Reproductive Health in Edinburgh, UK, found that it is vital for male fertility in mice.

The study, published in PLoS Genetics, showed that in mice without active Katnal1, sperm cells severed contact with Sertoli cells before they were fully mature, making the mice infertile.

'If we can find a way to target this gene in the testes, we could potentially develop a non-hormonal contraceptive', said study author Dr Lee Smith.

Dr Allan Pacey, a senior lecturer in andrology at the University of Sheffield, told the BBC that the key to developing such non-hormonal male contraceptives is to target only the genes that are involved in sperm production. Otherwise, he said the drug could have 'unwanted side effects on other cells and tissues in the body and may even be dangerous'.

Dr Smith added: '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'.

A separate study, published in the same journal, linked a different form of the katanin protein to male fertility. This team found sperm need it to swim properly and that without it, male mice are infertile.

'The take home message from these two studies is if we can better understand katanin we could target this for non-hormone male contraceptive development and we can look for new therapies for male infertility', said lead author Dr Liza O'Donnell, of Prince Henry's Institute of Medical Research in Victoria, Australia.