Scientists have found the gene, named Katnal 1, which controls the final stages of sperm development and could result in temporary infertility if blocked, writes The Telegraph.
The latest discovery will probably lead to the development of medicine, aimed to interrupt the production of fertile sperm without causing permanent damage.
The scientists, at the Centre for Reproductive Health at the University of Edinburgh, believe they can make the successful production of a contraceptive pill for men even in the near future.
To investigate the causes of male infertility, the researchers randomly altered the genetic code of mice to see which became infertile. They then traced the mutations which led to infertility, which led them to Katnal1.
The gene contains the blueprints for a protein, required to be in cells which support the development of sperm. Without the protein, sperm do not fully form and the body disposes of them.
Scientists hope they will be able to perform a similar trick in humans to stop sperm developing, without causing lasting damage.
Dr Lee Smith, from the university, said if “the gene was blocked the testes would continue to produce sperm, only releasing immature, ineffective sperm which had not developed into the final stages.”
He told the BBC: “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.”
“Although other research is being carried out into non-hormonal male contraceptives, identification of a gene that controls sperm production is a unique and significant step forward,” he said.
Dr Smith added it would be “relatively difficult” to do as the protein lives inside cells, however, he said there was “potential” to find something else that protein worked with, which might be an easier target.
Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said there was “certainly a need” for a non-hormonal contraceptive for men and that this had been a “Holy Grail” of research for many years.
He went on: “The key in developing a non-hormonal contraceptive for men is that the molecular target needs to be very specific for either sperm or other cells in the testicle which are involved in sperm production.
“If they are not, then such a contraceptive could have unwanted side effects on other cells and tissues in the body and may even be dangerous.”
“The gene described by the research group in Edinburgh sounds like an exciting new possible target for a new male contraceptive, but it may also shed light on why some men are sub-fertile and why their sperm does not work properly,” Dr Pacey added.