A gene-edited mouse born from an unfertilized egg has reached adulthood and has had a litter of its own, the Independent reports. It adds that this indicates parthenogenesis is not impossible in mammals, as previously thought.
Genomic imprinting in mammals has largely prevented parthenogenesis, but a trio of researchers from Shanghai Jiao Tong University has used targeted DNA methylation rewriting aimed at seven imprinting control regions to overcome that hurdle. As they report this week in the Proceedings of the National Academy of Sciences, they found altering single unfertilized oocytes in this way could yield mouse pups, though at a low success rate: 227 oocytes were reconstructed, 192 embryos were transferred to foster mothers, and three live pups were born, one of which survived. That surviving mouse, though, later had a litter with a male partner, showing normal reproductive performance.
"It's pretty cool but, it's nothing not to be expected in terms of what we've learned about how reproduction works and the genetic control of reproduction," Louis Lefebvre from the University of British Columbia tells the Daily Beast. "It's a tour de force in some way that [the researchers] really had to work hard in order to get it to work."