Sheep that´s 15% human

Source: Xinhuanet | 03-26-2007 15:35

Chimera: sheep have 15 per cent human cells and 85 per cent animal cells. (File Photo)

BEIJING, March 26 (Xinhuanet) -- Scientists have created the world's first human-sheep chimera -- which has the body of a sheep and half-human organs, according to news report Monday.

The sheep have 15 percent human cells and 85 percent animal cells and their evolution brings the prospect of animal organs being transplanted into humans one step closer.

Professor Esmail Zanjani, of the University of Nevada, has spent seven years and about 9.8 million dollars perfecting the technique, which involves injecting adult human cells into a sheep's foetus.

He has already created a sheep liver which has a large proportion of human cells and eventually hopes to precisely match a sheep to a transplant patient, using their own stem cells to create their own flock of sheep.

The process would involve extracting stem cells from the donor's bone marrow and injecting them into the peritoneum of a sheep's foetus.

When the lamb is born, two months later, it would have a liver, heart, lungs and brain that are partly human and available for transplant.

At present 7,168 patients are waiting for an organ transplant in Britain alone, and two thirds of them are expected to die before an organ becomes available.

Scientists at King's College, London, and the North East Stem Cell Institute in Newcastle have now applied to the HFEA, the Government's fertility watchdog, for permission to start work on the chimeras.

But the development is likely to revive criticisms about scientists playing God, with the possibility of silent viruses, which are harmless in animals, being introduced into the human race.

Animal rights activists fear that if the cells get mixed together, they could end up with cellular fusion, creating a hybrid which would have the features and characteristics of both man and sheep. But Prof Zanjani said: "Transplanting the cells into foetal sheep at this early stage does not result in fusion at all."

Editor:Du Xiaodan