It’s not every day that you get to write that scientists have created an animal-human hybrid, but today is that day. For the first time ever, scientists have created a human-sheep hybrid, and as strange and scary as that sounds, it’s actually for a really important reason.
A team at Stanford University is responsible for this human-sheep hybrid. They successfully grew embryos inside a surrogate (an unnatural, engineered animal) for three weeks, and the embryos had both sheep and human cells. The resulting creature is, according to Science Alert, “more than 99% sheep — but also a tiny, little bit like you and me.” So, no, you shouldn’t expect some crazy sheep-human creature to start roaming the earth any time soon.
Still, why would they do something that sounds straight out of a science fiction novel? The reasoning is pretty serious: This is the first big, important step toward growing organs inside of sheep for use in human transplants or to cure diabetes. This could ultimately mean an unlimited supply of human organs for these medical reasons, which could open up a lot of doors in the scientific and medical worlds.
They aren’t done yet, though: The next step is to implant human stem cells into sheep embryos that have been genetically modified so that they cannot grow a pancreas — scientists hope that human DNA will fill in the middle code. If they’re successful, a human pancreas will appear inside the sheep’s body. The team needs to apply for permission to do this, which they’ve already done.
The work might not be done just yet, but scientists seem confident that it will be successful. Dr. Hiro Nakuachi, who is leading the research, spoke at the American Association for the Advancement of Science annual meeting in Austin, Texas, and said that he thinks organs grown in animals will be available for transplant in the next five to 10 years.
According to the Telegraph, sheep have a similar heart and lungs to humans, and their embryos have been used to create other hybrids before. Another researcher, Dr. Pablo Ross, said, “The size of the sheep organs is similar to human size, some of the organs are physiologically similar between sheep and humans, and a lot of cardiovascular research is done in sheep because it has some similarities to humans in terms of heart shape.”
The researchers on the team seem confident and positive, but not everyone agrees. Robin Lovell-Badge from the Francis Crick Institute in London says the organs will be rejected by the human body: “Even if they succeed in replacing all pancreatic cell types in the sheep with human cells, the blood vessels within the pancreas will be sheep-derived. The organs could not be used for transplants into humans without triggering the immune system to reject them — and this would probably be a very fast rejection.”
The experiment, of course, has brought up many ethical questions and moral dilemmas. However, many researchers and scientists feel like it’s worth it.
Ross also said, “All of these approaches are controversial, and none of them are perfect, but they offer hope to people who are dying on a daily basis. We need to explore all possible alternatives to providing organs to ailing people.”