PIONEERING research carried out by scientists in Edinburgh to produce Dolly the cloned sheep has been copied by an international team in Hawaii with mice.

The breakthrough, creating a batch of 22 mice, was announced yesterday in the science journal Nature. It will provide a launching point for basic cloning research enabling future development of the technology.

Professor Ian Wilmut, who led the Dolly team at the Roslin Institute, said: ''These are exciting results. They suggest that it will be possible to produce adult clones from a range of different cell types and species.

''Research into mice is much less expensive than in large animals such as sheep and cattle. The work published today will encourage many laboratories, including our own, to use mice in studies to understand the basic mechanisms involved in the 'reprogramming' of adult cells. Studies on mice will also facilitate the use of nuclear transfer for studying mechanisms involved in ageing and in cancer.''

Scientists believe mice are the perfect tool for cloning experiments where the cost of using large mammals would be economically impossible. Mice have a short gestation period, are well understood genetically, and have embryos that are much easier to manipulate than those of larger mammals.

The mice created by Ryuzo Yanagimachi, from the University of Hawaii, Honolulu, and an international team from the US, Japan, Italy, and the UK, seem perfectly normal and have been successfully mated to produce offspring.

The mice were derived from nuclei taken from cumulus cells - ovarian cells that surround the egg and are shed with it on ovulation.

These were transferred to mouse egg cells whose own nuclei had been removed. The technique is the same as that employed by scientists at the Roslin Institute, Edinburgh, to produce Dolly, the first mammal cloned from an adult cell, in July 1996.

Professor Davor Solter, from the Max-Planck Institute of Immunobiology in Freiburg, Germany, said of the results: ''The importance of this report cannot be over emphasised.''

He said cell and tissue therapy, preservation of important livestock lines, and saving endangered species were all areas where cloning could be of enormous benefit.

He added that at some point it will be necessary to decide whether human cloning should be attempted. But he warned: ''We must remember that cloning is not an instant duplication, so mad dictators will not be able to expand themselves into huge armies of doppelgangers, nor will the bereaved be able to restore their lost ones.''

In the work at Hawaii, only nuclei from cumulus cells produced viable clones. Other experiments using nuclei transferred from nerve cells and cells taken from the testicles ended in failure.

Overall the success rate ranged from one in 40 to one in 80 survivors for every embryo implanted.

The mouse experiments indicate that some adult cells can be cloned while others cannot, but at present no-one knows why.

Another report in the issue of Nature said Dolly's authenticity was proved beyond doubt. Dolly was produced from an udder cell taken from an adult ewe. But because the ewe was pregnant at the time, some have suggested that through an accident Dolly was descended from a contaminating foetal cell and not a clone after all.

However, work carried out at the University of Leicester described DNA profiles showing that Dolly definitely was a clone of the six-year-old donor ewe.