Science adviser backs animal eggs for human stem cells

The UK Government's chief scientific adviser has expressed his support for proposals to use animal eggs in the creation of human embryonic stem cells (ES cells) for research purposes. Sir David King said last week that such work should be allowed under tight regulations, adding that it was crucial for scientists to gain the public's trust and approval to avoid a 'GM (genetically modified) food-style' backlash. Sir David was speaking at a public seminar organised by the House of Commons Science and Technology Committee, which is currently conducting an inquiry into the issues surrounding research on embryos containing both human and animal material.

The Human Fertilisation and Embryology Act 1990 is currently under review, and a Government White Paper published last December proposed that the creation of 'hybrid' and 'chimera' embryos should be banned by the new law. A draft Bill is expected in April, with legislation likely to be updated in 2008. The Human Fertilisation and Embryology Authority (HFEA) has already received applications from two research teams who want to use 'hollowed-out' cow or rabbit eggs to generate human embryonic stem cells. However, as the current Act does not explicitly refer to this type of research, the HFEA has deferred making a policy decision until a public consultation has been carried out.

The embryos in the proposals would be at least 99.9 per cent human, with a tiny amount of cow or rabbit DNA contributed by the animal cells' mitochondria - tiny structures that generate the cell's energy. The scientists want to use such embryos, dubbed cytoplasmic hybrid or 'cybrids', to create ES cell lines from patients affected by conditions such as diabetes, Parkinson's disease and motor neuron disease. These cells could be used to shed light on how the illnesses develop, and to test out new treatments.

Prime Minister Tony Blair said last month that although there were difficult issues, the Government was 'not dead set against' the creation of hybrid embryos for research. The Department of Health said in a statement that 'the proposal in the white paper is that a draft bill will clarify the extent to which regulation will apply to the creation of human-animal hybrids', adding 'we are proposing that these embryos should be prohibited but with a regulation-making power to make exceptions to that prohibition'.

However, according to the Times newspaper, while ministers will not yet endorse the research in full, they are no longer seeking legislation to prohibit it, fearing that such a ban will damage British science. Government sources have reportedly said that the Department of Health failed to fully understand the importance of hybrid embryos or the work that scientists wanted to do, prompting a rethink.