09 October 2006
ByAppeared in BioNews 379
British scientists from three separate research centres have announced their intention to submit simultaneous proposals to the Human Fertilisation and Embryology Authority (HFEA) later this month seeking a licence to create human-animal chimeras. The researchers - based in London, Newcastle and Edinburgh - are seeking approval to carry out experiments where they will remove the nucleus from either rabbit or cow eggs and replace it with the nucleus from a human cell. The groups hope that the new research will enable them to perfect the technique of CNR, also known as therapeutic cloning.
The hybrid embryos would be 99.9 per cent human with a 0.1 per cent rabbit or cow component. The vast majority of genetic material in the cell is housed in the nucleus, but a small number of genes are also carried in the cell's mitochondria - the parts of the cell that provide energy. It is this mitochondrial DNA which would continue to provide a small amount of animal identity in the resulting cells. There is no possibility of the embryos being allowed to develop beyond the 14 day limit for embryonic research, as the licences - if granted - would guarantee destruction of the chimeras at this point or before. The scientists hope it may be possible to extract stem cells from the chimeras allowing research to progress into serious disorders such as Alzheimer's and Parkinson's disease.
Two of the research groups, led by Dr Stephen Minger of King's College London, and Professor Ian Wilmut of Edinburgh University, plan to use the chimeric embryos to create stem cell lines to investigate neurological disorders with a known genetic basis. The Newcastle group want to insert skin cell nuclei into animal eggs in order to study how eggs can 're-programme' adult cells back into a more primitive state. Professor Chris Shaw of the Institute of Psychiatry in London who is collaborating with the London and Newcastle teams said, 'If we learn how to do this with animal eggs, we should be able to have more success with human eggs, and I'd much rather know that if we were going to ask women to donate eggs that we were very likely to get stem cells as a result'.