New hope to end infertility

SPERM cells have been created in the laboratory, offering hope for a cure for a common cause of male infertility.

Around 1 in 500 men have an extra X or Y chromosome, which disrupts their sperm production. Using male mice, scientists at the Francis Crick Institute in London created multi-purpose stem cells – which can be used to create any type of cell – from ear tissue.

These were treated to become sperm cells. Injected into the mouse’s testes, they became fully functioning sperm, allowing the mice to fertilise females.

If the same technique were to work in human stem cells, it could allow many sterile men to become fathers. Such a treatment would require a change in the UK law that bans the use of artificially produced sperm to make babies.

The scientists have already taken a first step towards human treatment by conducting preliminary experiments involving men with an extra sex chromosome. They showed it was possible to produce stem cells from their tissue that did not have the extra chromosome.

It should be possible to turn these cells into fertile sperm, although much further work is needed on the process, the researchers say in the journal Science.