UK team create cloned human embryos

Scientists based in Newcastle, UK, have created cloned human embryos, one of which grew in the laboratory for five days. The team is one of only two UK groups licensed by the Human Fertilisation and Embryology Authority (HFEA) to carry out 'therapeutic cloning' research. The achievement, currently being considered for publication in the journal Reproductive Biomedicine Online, was announced on the same day that a Korean team published details of 11 new cell-lines derived from cloned human embryos.

The Newcastle scientists hope to use cloned human embryonic stem cells (ES cells) to develop new, tissue-matched treatments for type 1 diabetes and other diseases. They used 36 eggs (oocytes), donated by 11 women, from which they removed the genetic material and replaced it with that of a human cell. Three of the resulting cloned embryos survived for three days, and one survived for five days. The success of the technique seemed to depend on how quickly the egg was collected and manipulated, say the scientists - the embryo that survived for five days was derived from an egg that was collected and processed within 15 minutes.

Team member Alison Murdoch stressed that it would be some time before the research led to new treatments, saying that it would be 'several years before we are talking about a cell-based therapy that can go back into the patient'. One of the things that might slow down the progress of the research is a shortage of donated eggs. For the latest work, the Newcastle group used fresh eggs, collected from women undergoing fertility treatment. Professor Murdoch said that if a woman has 20 eggs, her chance of getting pregnant is no higher than if she has 18, 'so on that basis we can be very confident that the women who donate would not significantly decrease their chances of having a baby'.

However, the Korean team reported greater success using fresh eggs from young, fertile women, rather than eggs left over from fertility treatment. UK scientist Ian Wilmut was granted the country's second licence to clone human embryos for research earlier this year. Wilmut is now set to join forces with the Korean scientists, on a project aimed at developing new treatments for motor neurone disease. He believes that the research will not be successful using IVF eggs, and so is reported to be seeking a change in the licence so that the team can ask women to donate eggs specifically for the work. He thinks that 'a number' of women will be prepared to do so, saying: 'this will allow us to obtain fresh oocytes and we hope to have the first cell lines for research by the end of the year'.