Growing organs is something we associate with mad scientists — but it could soon become a part of modern medicine. In the latest advance, researchers have created the first embryo that's made of both sheep and human DNA.
Researchers used genetic editing tools to put human stem cells inside a sheep embryo. They found the embryos grew even though about one in every 10,000 cells in the embryo were human.
The experiment is striking because it shows how other animals could become organ incubators. Stem cells are unique because they can grow into just about any kind of cell. This procedure shows they might be used to grow human body parts — even if they're in a different species' embryo.
But some scientists are concerned the method isn't ethical or practical. For this to work, researchers say at least 1 percent of an embryo's cells need to be human. But having that many human cells in an animal leaves a slim chance it could develop unnaturally human qualities, like altered intelligence.
But if scientists do figure out how to do this safely, it could save a lot of lives. On an average day, about 20 people waiting for an organ transplant die, while someone is added to a national transplant list every 10 minutes.