Scientists in Japan say they have succeeded in breeding mice with two fathers, using eggs originating from male cells. While the scientific breakthrough could pave the way for new fertility treatments, experts say it is still a long way from being used in humans.

Katsuhiko Hayashi, a renowned biologist at the University of Osaka, said his team had used chromosomal engineering to breed seven “healthy” mice pups, hailing a “first case of making robust mammal oocytes (eggs) from male cells”.

Hayashi made the announcement at the Third International Summit on Human Genome Editing at the Francis Crick Institute in London on March 8, prompting a flurry of excitement and speculation about the discovery’s implications for the future of human reproduction.

The study’s results have been submitted for publication in the scientific journal “Nature.” If confirmed, they would mark a “small revolution”, said Dr. Nitzan Gonen, head of the Sex Determination Lab at Israel’s Bar-Ilan University in Tel Aviv.

Biologists and geneticists have been working towards this feat for more than a decade, hoping to develop new treatments for severe forms of infertility or even allow for single-parent embryos.

The discovery in Japan also raises the prospect of same-sex couples being able to have a biological child together in the future, though experts caution that a number of hurdles remain before a leap from the lab to the clinic.

A father’s egg

The ethical ramifications of Hayashi’s discovery are also certain to stir debate.

Read more on FRANCE 24 English

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