Cloning team looks to human embryos

Ian Wilmut, leader of the team which cloned Dolly the sheep, is to plunge into uncharted scientific waters by trying to clone human embryos for research.

Professor Wilmut, who stresses that any human clones he creates will not develop beyond the stage of a microscopic cluster of cells, hopes to be the first to take advantage of a change in British law allowing the procedure to be attempted.

He told a conference in Berlin this month that he hoped his laboratory, at the Roslin Institute near Edinburgh, would apply for a licence to start work from the Human Fertilisation and Embryology Authority (HFEA) within the next six months.

Prof Wilmut's plan is controversial because it seeks to create cloned embryos not, as has been speculated, for growing cells and organs for transplant, but for research into diseases. This could provide an alternative to animal testing, although opponents of any kind of cloning will find the idea of "embryos for medical testing" as easy to condemn as "embryos for spare parts".

Prof Wilmut also seeks to combine two technologies - animal cloning and the cultivation of human embryonic stem cells - which are experimental and, so far, unreliable.

The Roslin Institute will not be able to carry out the research without a steady supply of human eggs, which must be supplied by women donors.

Existing embryonic stem cell research uses human embryos donated by couples undergoing IVF treatment, which would otherwise be destroyed or frozen. But women donating eggs for research would be offering eggs which could otherwise be used to help infertile couples have children.

Prof Wilmut said his colleagues in Edinburgh were already working on techniques to obtain eggs from volunteers without them going through the uncomfortable and inconvenient procedures necessary for women undergoing IVF.

"I had an email from a lady saying she supports this research, and that she would be pleased to donate eggs," he said.

The Wilmut research proposal is to take cells from patients with genetic diseases. Scientists would remove the gene-encoding DNA from the nucleus of one such cell and put it into a hollowed, donated egg. Using the same procedure as that which created Dolly, a jolt of electricity would fuse the two and the new entity, the first cell of a cloned human embryo, would begin to divide.

In theory, stem cells harvested from this embryo could be made to replicate themselves indefinitely and be used as a target for research into medicines to combat the disease.

Prof Wilmut's background is in animal rather than human medical research, and the Roslin would have to collaborate with medical researchers in other institutions, as well as IVF clinics, in order to carry out the work.

The idea will have to be approved by a series of committees, initially within the Roslin, before it lands on the HFEA's desk.