Scientists said they made a mouse from two biological fathers.
At a conference, they said they made female eggs from male cells.
The study, which is very early, raises hope that same-sex partners can have biological children.
Scientists claim they’ve created mice with two fathers in a breakthrough that could one day be replicated in humans.
Katsuhiko Hayashi of Osaka University told the Human Genome Editing conference on Wednesday that he made the breakthrough after changing the chromosomes in a male cell from XY to XX.
He then used that technique to create female eggs, called ova, from male cells and fertilized them to create seven mice with two biological fathers.
The discovery has yet to be validated by a peer review and is still in the early stages of development. Still, if confirmed, it raises the prospect that male couples will one day have their own biological children.
The male-to-female eggs were made from skin cells
Cells are pliable, and with the right cues, scientists have learned to make them change from one type of cell to another.
To create the egg, the scientists took male skin cells with X and Y chromosomes and reprogrammed them so they would turn into so-called pluripotent stem cells, which are cells that can turn into any other type of cell.
They then removed the Y chromosomes in the cells and duplicated the cells’ X chromosomes, before prompting the cells to turn into egg cells with two X chromosomes.
“The trick of this, the biggest trick, is the duplication of the X chromosome,” Hayashi told The Guardian. “We really tried to set up a system to duplicate the X chromosome.”
The technique was used to create seven mice pups, which scientists said appeared healthy.
Hayashi says it could be used in humans within a decade, while others disagree
It will be some time before the technology is ready to be used safely in humans.
Mice are very different from humans, and even in mice the eggs aren’t great quality — only one in 100 fertilized eggs led to a live birth, Hayashi said, according to the Guardian.
Still, Hayashi is optimistic. From a purely technological point of view, he predicts that making eggs from male cells in humans “will be possible even ten years from now,” he said, according to The Guardian.
He told the BBC he would like to see the technology bring fertility options to same-sex partnerships of all genders over time. The technique could also help women and people with two X chromosomes who have a genetic problem with one of the X chromosomes have children, he said.
He warned that it must be proven in advance that it is safe for use.
“Technically, this is possible. I’m not too sure if it’s safe or acceptable to society at this stage,” he said.
George Daley, dean of Harvard Medical School who is not involved in the research, told the BBC the work was “fascinating” and “provocative,” but he wasn’t so sure that this technology would work on human cells any time soon.
Human reproductive cells are very complex and much less known than mouse cells. So there is a long way to go before these fertility options can be offered to people, Daley told the Guardian.
The discovery is promising, although this isn’t the first time a mouse has been born to two fathers. A 2010 study managed to do this, but their technique required many more steps and manipulation of the embryo and did not create a viable egg. Hayashi’s approach, according to The Guardian, is much more straightforward.
Hayashi also previously created mice with two birth mothers using the same technique, dating back to 2016. We are still unable to make a viable human egg from female skin cells, seven years after Hayashi’s paper in female mice, reported The Guardian.
“Scientists never say never, basically it’s been done in mice, so of course it could be possible in humans,” Haoyi Wang of the Chinese Academy of Sciences told the BBC. But, he added: “I can foresee a lot of challenges and I couldn’t predict how many years that would be.”
It could be, but is it ethical?
If technology got to that point, it would be up to society to decide if we would allow people to use it to create children.
The use of germline gene editing in humans – when DNA is modified in such a way that the manipulation is passed on from scientists to the offspring of the children themselves – has typically been a constant thread for scientists.
When scientist He Jankui crossed that line in 2019 and announced that he had edited the genes of two babies, he received an international admonition and was sentenced to prison.
But if Hayashi’s research can open up new possibilities for human reproduction, the technology could be considered in the future.
Read the original article on Business Insider