Human-sheep hybrids have been created by scientists for the first time, opening the door to organs being grown inside the farmyard animals for use in transplants or to cure diabetes.
A team at Stanford University successfully grew embryos inside a surrogate for three weeks which had both sheep and human cells.
It is the first stage towards growing an unlimited supply of human organs for transplants and even providing a cure for Type 1 diabetes.
The next step is to implant human stem cells into sheep embryos which have been genetically modified so they cannot grow a pancreas, in the hope that human DNA will fill in the missing code.
If successful a human pancreas should appear inside the animal’s body.
The team is about to apply for permission from regulators to lengthen their experiment to 70 days to see if the human cells really can create an organ.