By Steve Connor, Science Editor

25 November 2002

The scientist who cloned Dolly the sheep has applied for a government licence to work with human eggs in an experiment that prepares the way for human cloning.

Professor Ian Wilmut's application to the Human Fertilisation and Embryology Authority (HFEA) covers a technique in which an unfertilised egg is stimulated in the laboratory to develop into an early embryo.

The procedure is called parthenogenesis, which literally means "virgin birth", and results in the creation of cloned embryos that develop without the need for sperm to fertilise an egg.

Professor Wilmut's laboratory, at the Roslin Institute near Edinburgh, will not allow the "parthenogenically activated" human eggs to be implanted into the womb, which is illegal in Britain.

The institute's application to the HFEA says the research is intended to grow the human embryos in a test tube to a few days old when scientists can extract embryonic stem cells for further study. Harry Griffin, acting director of the Roslin Institute, said: "We can confirm that we have made an application to the HFEA for a licence under the Act but we're not prepared to comment on the details of an ongoing process."

Robert Lanza, from Advanced Cell Technology, based in Massachussetts, said that by carrying out parthenogenic activation of human eggs, Professor Wilmut would gather important insights that were necessary for the sort

of cloning that led to Dolly, in which genetic material was transferred from an adult cell into an "empty", unfertilised egg.

"In the field of cloning, before you proceed with nuclear transfer of any species, you need to work out the activation protocol," Dr Lanza said.

"Essentially, that is learning how to fool the egg into thinking it is fertilised because obviously there will be no sperm."

Creating human embryos by parthenogenesis may circumvent many of the ethical concerns of generating embryos by the Dolly technique. In America, for instance, the embryos created by parthenogenesis are not even considered

to be embryos by some scientists, who refer to them as "parthenotes". There is also the question of whether the parthenogenically activated eggs are considered embryos under the 1990 Act, which defines an embryo as an egg

fertilised by a sperm.