Plans for human–animal stem cells stalled

British researchers have been denied permission to create controversial human–animal-derived hybrid embryos until doubts about the ethics and scientifi c value of the research are addressed. The Human Fertilisation and Embryology Authority said it was deferring a decision on whether to grant licences to teams from King's College London and Newcastle University until a wide-ranging consultation on the issue concluded in the autumn. Scientists claim that stem cells from hybrid embryos will be vital to unravel the mysteries of Alzheimer's, Parkinson's and motor neurone diseases, and will pave the way for techniques capable of transforming skin cells from an adult into different tissues and organs. Opponents protest that the creation of embryos that are part human, part animal is abhorrent. Last month, a government white paper outlining plans to update regulations included proposals to ban the creation of hybrid embryos. The government is due to produce a draft bill on the issue next month, which will be scrutinised by a parliamentary committee before debate. Scientists believe it is possible to harvest human embryonic stem cells from cloned embryos, which are created by transplanting the genetic material from an adult cell into a hollowed-out egg. Human eggs are in short supply and subject to other ethical issues but, with plentiful supplies of animal eggs, scientists believe they could perfect the technique of creating embryos as a source of stem cells in this way. The hybrid embryos would be more than 99 per cent human, with animal DNA contained in mitochondria. Experts met at the HFEA ahead of last month's decision and decided it was premature to issue research licences. Angela McNab, the chief executive, said in a statement: " This has proved complex and challenging as the law in this area is far from explicit and this area of research would be a signifi cant step change in UK science. There is not clear agreement within the scientifi c community about the need for and benefi ts of this science. The authority felt that it is important that we go through the issues and the science thoroughly and test the claims about the benefi ts of this research. " The UK has some of the most supportive legislation for research on human embryonic stem cells but the latest proposal for human– animal hybrids has prompted wider consultation. head of the King's College team, said: " We're happy for the consultation to …