The chimera process

Here are some key facts about the chimera process:

How is a chimera created?

First, DNA is removed from a pig embryo to allow it to grow a pancreas. Then human induced pluripotent (iPS) stem cells are injected into the developing pig, which scientists hope will force the foetus to grow a human pancreas.

What are the ethical considerations?

Animal rights organisations oppose these kinds of experiments on the grounds of the suffering caused to the animals and the prospect of organ farms. The National Institutes of Health, a US medical research agency, imposed a ban on funding experiments like this last year.

What could this mean for organ transplants?

If successful, the chimeras could potentially be used to grow not just a pancreas but hearts, livers, kidneys, lungs and corneas.

Walter Low, professor in the department of neurosurgery, University of Minnesota, described pigs as an ideal “biological incubator” for growing human organs.

Are there any risks involved?

Previous clinical trials to use genetically modified pigs for organ transplant stalled because of fears humans could be infected with animal viruses.

There are concerns that the human cells might move up to the foetus’s brain and make it more human.