A Japanese researcher has told a major genetics conference that he has created female mouse eggs from the cells of male mice.
His research, which is still in its early stages, involves changing the male XY sex chromosome into a female X chromosome.
Professor Katsuhiko Hayashi of Osaka University is working on developing a female fertility treatment.
The development, which he presented for publication in the scientific journal Nature, increases the chances of male couples having children of their own.
Harvard Medical School professor George Daly, who was not involved in the research, said society still has a long way to go before it faces such a decision.
“Hayashi’s work is unpublished but fascinating,” said Professor George Daly. (Doing this on humans) is more difficult than on mice. “We do not yet understand the unique biology of human gametogenesis enough to reproduce Hayashi’s remarkable function in mice.”
Details of the research were presented at the Human Gene Editing Summit at the Crick Institute in London.
Professor Hayashi, a globally respected expert in the field, told delegates at the meeting that the work was at a very early stage. They said the eggs were of low quality and the technique could not be safely used on humans at this stage.
But he said he could see the current problems overcome in 10 years and would like to see it available as a reproductive option for both men and women and same-sex couples if it is proven to be safe to use. .
“If people want it and if society accepts such technology, then yes, I’m all for it.”
The technique involves first taking a skin cell from male mice and then turning it into a stem cell – a cell that can transform into another type of cell.
The cells are male and therefore contain XY chromosomes. Professor Katsuhiko’s team then deletes the Y chromosome from these cells, duplicates the X chromosome and then glues the two X’s together. This adjustment allows the stem cell to be programmed to become a female egg.
This technique can be used to help infertile couples where the women are unable to produce their own eggs. However, he stressed that it is far from being available as a fertility treatment.
He said that there are many problems in egg quality in mice too. So before we can think of using it as a fertility treatment, we have to overcome these issues, which may take a long time.”
Professor Hayashi said he would not be in favor of a man using his own sperm and artificially created eggs to have a baby.
Technically it is possible. I’m not so sure it’s safe or even socially acceptable at this stage.
Professor Emander Clark, a stem cell scientist at the University of California, Los Angeles, said the LGBTQ+ community should be given the opportunity to have a say in the use of reproductive technology.
‘The LGBTQ+ community has unique needs when it comes to having a family.’ .
However, the technology is not currently available for human use, its safety and efficacy have not been proven, and it is unclear how long it will take for the technology to reach the clinic. Much remains to be learned about the journey of the human germline. Knowledge gaps act as barriers to translating this research to humans.
Cultural differences
Alta Charo, a law professor at the University of Wisconsin-Madison, said that if the technology becomes available, different cultures will have “very different ideas” about its use.
“In some societies the genetic contribution to one’s children is considered absolutely necessary, and for them the question is, ‘Is this a step to take?’ For those who are not in conflicting order.’
‘For other societies that is not so important, and adopting children is perfectly acceptable, because for them family relationships are more about personal relationships and less about biological connection.’
Professor Huai Wang of the Chinese Academy of Science believes there is still a long way to go before the technology can be used in the clinic.
‘Scientists never say never, in principle this experiment has been done in mice, so of course it could be possible in humans, but I can imagine a lot of challenges and I don’t foresee that. After how many years will this happen?’