Professor Ian Wilmut, who first cloned a sheep, Dolly, said on Tuesday he has been granted a UK licence to use cell nuclear replacement to study motor neurone disease (MND).

He said in a statement that researchers at the Roslin Institute near Edinburgh and King’s College London plan to generate stem cells that carry MND-causing gene defects. By turning these stem cells into motor neurones they would have a “unique opportunity” to discover what causes these cells to degenerate.

“We will compare the behaviour and chemical profile of neurones with the gene defect to those without. This will tell us about the earliest events that ultimately lead to cell death,” said Professor Christopher Shaw, from King’s College.

The cultured neurones will also be used to discover drugs that can stop or reverse the disease process, the scientists added.

“Hundreds of thousands of drugs can be quickly screened in cultured cells within a year for around 100,000 pounds (146,000 euros), whereas it takes nearly two years and 20 million pounds (29 million euros) to screen just one drug in MND patients.

“This technique could dramatically accelerate the discovery of new drugs that can effectively block the disease process,” they said.

“This is potentially a big step forward for MND research,” Shaw said. “We have spent twenty years looking for genes that cause MND and to date we have come up with just one gene. We believe that the use of cell nuclear replacement will greatly advance our understanding of why motor neurones degenerate in this disease, without having to first hunt down the gene defect.”

To generate stem cells, the researchers will first grow skin or blood cells from people with an inherited form of MND for which the genetic cause is unknown. They will then remove the nucleus from an unfertilised egg, and replace it with the nucleus of a cell from a familial MND patient.

Eggs that have successfully received the nucleus containing the MND-causing gene defect will be encouraged to grow up to the 200-cell stage. Then embryonic stem cells will be removed, grown and directed to become motor neurones using a cocktail of growth factors.

“This is not reproductive cloning in any way,” Wilmut noted. “The eggs we use will not be allowed to grow beyond 14 days. Once the stem cells are removed for cell culture the remaining cells will be destroyed. The embryonic stem cells that we derive in this way will only be used for research into motor neurone disease.”

Therapeutic cloning for research has been legal in the UK since 2001. This is the second licence granted by the Human Fertilisation and Embryology Authority, which approved another research team in Newcastle last year.