Researchers grow sheep embryos containing human cells

Researchers have announced that they have grown sheep embryos containing human cells. According to scientists, growing human organs inside animals could not only increase supply, but also offer the possibility of genetically tailoring the organs to be compatible with the immune system of the patient receiving them. Given that the patient's own cells will be used in the procedure, this eliminates the possibility of rejection.

According to NHS Blood and Transplant, around 460 people died in 2016 waiting for organs, while organ rejection is sometimes seen in people who receive the transplants.

''Even today the best matched organs, except if they come from identical twins, don't last very long because with time the immune system continuously is attacking them,'' said Dr Pablo Ross from the University of California, Davis, who is part of the team working towards growing human organs in other species, The Guardian reported.

He added that if it were to become possible to grow human organs inside other species, it might be that organ transplants become a possibility beyond critical conditions.

According to Bruce Whitelaw, professor of animal biotechnology at the Roslin Institute, where Dolly the sheep was created, while there was a long way to go before human organs could be grown in other animals, the latest research is ''an important step forward through starting to explore whether sheep offer an option for the exciting 'chimeric' project.''

With the development researchers have created a new kind of chimaera. In the medical world, a chimaera is an organism with a mixture of genetically different tissues and is formed by processes such as fusion of early embryos, grafting or mutation.

The scientists were able to create the sheep-human hybrid by introducing human stem cells into the sheep embryos. The chimaera thus formed was more than 99 per cent sheep and a little bit human.

According to experts although the human portion of the organism thus formed was extremely small, the fact that it existed would likely lead to fresh debates in the field of research. By cell count, only about one in 10,000 cells in the sheep embryos were human.