Scientists successfully created healthy mice from 2 male parents

Scientists have successfully created mice with two biologically male parents, according to new research presented at the Third International Summit on Human Genome Editing in London. This was done by manipulating the chromosomes of one of the mice and creating an egg, "a significant advance with significant potential applications," said Keith Latham, a developmental biologist at Michigan State University.

After creating the eggs, they were fertilized by male sperm cells and implanted in female mice's uteruses. The survival rate of the embryos was low with only seven of 630 developing to become pups. However, those seven grew normally and become fertile adults. "This is the first case of making robust mammal oocytes from male cells," said Katsuhiko Hayashi of Kyushu University who lead the research.

The next step is to apply the technique to human cells, but "there are big differences between a mouse and the human," Hayashi explains. "Purely in terms of technology, it will be possible [in humans] even in 10 years," he adds, saying he's unsure "whether they'll be available for reproduction."

The technology could potentially be used to allow male couples to have biological children in the future. "What I can say is only about the technological side. I think in theory it is possible," Hayashi told New Scientist. Kotaro Sasaki, a biomedical scientist at the University of Pennsylvania commented, "Using this for reproductive purposes ... comes with lots and lots of ethical and legal issues, which we need to seriously address."

The findings are yet to be published in a scientific journal, making it "preliminary research," according to Evelyn Telfer, a reproductive biologist at the University of Edinburgh.

"Although they get quite a lot of eggs, these eggs are clearly not fully competent because they really get a very, very small proportion of them that are capable of being fertilized and forming embryos," she said. "It's a huge achievement, but it's still an indication that there are problems with these in vitro–derived oocytes from the stem cells, so there's a lot of work that has to be done."