Genetically edited piglets are helping scientists take a major step on the path towards using live animal organs in humans, also known as xenotransplantation.
By removing potentially harmful retroviruses found in pig DNA, the experiments are opening up the possibility of humans one day safely receiving pig organs, according to the study published in the journal Science.
Geneticist Dr George Church told The New York Times that the first pig-to-human organ transplants could occur within two years.
Researchers from Harvard University and biotech startup eGenesis took cells from pigs and snipped the viral DNA from their genomes, and then cloned the edited cells.
These edited cells were then developed into embryos and grown into genetically identical piglets.
The cloning process hasn't been fully perfected yet — out of the thousands of embryos transferred to 17 sows, only 15 piglets remain alive.
However they are all successfully PERV inactivated, with the oldest one at four months old. The scientists are now conducting long-term studies to see the impact of the gene editing.
EGenesis chief scientific officer Luhan Yang said the research was an "important advance" in addressing safety concerns about possible viral transmission during organ transplantation.
There are still many other hurdles to overcome before successful xenotransplantation could occur.
The next stage of research would involve more genetic changes to pigs to modify the organs, as well as more lab tests before testing in humans can occur.
