Medical News Today
Fri, 12 Jan 2007 12:05 CST
The UK's Human Fertilisation and Embryology Authority (HFEA) has decided to open the question of whether to allow animal-human hybrid embryos to be developed for research purposes to public debate. The HFEA licenses and monitors IVF and donor insemination clinics, and research centres that use embryos. They also regulate the storage of embryos, eggs and sperm.
The HFEA has received two requests from scientists who want to use human cells and animal eggs to produce stem cells for research.
Members of the authority met yesterday to decide whether it was in their remit to grant such a request, and if so, then how best to go about it.
Chief Executive of the HFEA, Angela McNab, said earlier today that "the issues around hybrid and chimera research are unique and different from mainstream human embryo research." She adds that the law is not clear and that such research would lead to "a significant step change in UK science."
The HFEA decided two things. First, that it is in their remit to regulate human-animal hybrid and chimera research, and secondly, that the public should be consulted to establish in principle, whether such research should be allowed in the UK.
The debate, which is to conclude in the Autumn, is likely to be heated and although the issues are not "black and white" as Ms McNab points out, there are many who see them so in principle. Some say that this kind of research is vital if we are to develop effective treatments for degenerative diseases such as Alzheimer's and Parkinson's, others say that this is a step too far and crosses into unethical territory.
The HFEA has received applications to create human-animal hybrids from Newcastle University and King's College London. The scientists want to take a cow's egg, strip it of its genetic material, and fuse it with human DNA. This is a similar method to the one that made Dolly the Sheep, except in that case it was DNA from a sheep that was fused with the DNA-stripped egg of a sheep.
Chimeras and hybrids are not the same. A chimeric embryo is produced when the embryo that develops has cells with two (or more) different DNA donors. It's like two individuals with distinct identities "fused" into one body, for instance with brain cells of one and liver cells of the other identity. Chimeras occur in nature, and there could be chimeric humans around who do not realise they are chimeric because the only way to test for it is by DNA testing. There are rare occasions when organs from both identities develop, as for instance in hermaphrodites.
Other countries have produced animal-human hybrids and chimeras to make stem cells. In China for instance, scientists in 2003 developed human-rabbit chimera using human skin cells with rabbit eggs. The embryos were destroyed after a few days and the stem cells harvested.