Now scientists create a sheep that's 15% human (Goal is to produce organs for human transplant)
Pastor Dale Morgan
Now scientists create a sheep that's 15% human (Goal is to produce
organs for human transplant)*
This Is London ^ | March 25, 2007
Posted on 03/25/2007 10:57:38 AM PDT by Stoat
Scientists have created the world's first human-sheep chimera - which
has the body of a sheep and half-human organs.
The sheep have 15 per cent human cells and 85 per cent 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 £5million perfecting the technique, which involves injecting
adult human cells into a sheep's foetus.
Chimera: sheep have 15 per cent human cells and 85 per cent animal cells
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.
"We would take a couple of ounces of bone marrow cells from the
patient,' said Prof Zanjani, whose work is highlighted in a Channel 4
programme tomorrow.
"We would isolate the stem cells from them, inject them into the
peritoneum of these animals and then these cells would get distributed
throughout the metabolic system into the circulatory system of all the
organs in the body. The two ounces of stem cell or bone marrow cell we
get would provide enough stem cells to do about ten foetuses. So you
don't just have one organ for transplant purposes, you have many
available in case the first one fails."
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.
Dr Patrick Dixon, an international lecturer on biological trends,
warned: "Many silent viruses could create a biological nightmare in
humans. Mutant animal viruses are a real threat, as we have seen with HIV."
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."