Cloned sheep can reproduce

Scottish scientists expect to hear the clatter of tiny cloned hooves next month, following the news that the two sheep cloned before Dolly are pregnant. Morag and Megan, the two-year-old sheep which were produced by cloning from embryo cells - rather than a full-grown adult, as Dolly was - are due to give birth to lambs in May and July respectively, after the standard five-month gestation.

The news has encouraged the team at the Roslin Institute, near Edinburgh, which announced the cloning of Dolly in February. "It's a further demonstration that these sheep are perfectly normal," said Dr Harry Griffin, one of the project members. Morag and Megan mated normally, which means that their offspring will not be identical, as their genes will have mixed with the lambs' father's.

Dolly, the world's first clone from an adult cell, is now nine months old, and will probably be mated early next year.Some scientists had speculated that Dolly, unlike Morag and Megan, might have a shortened lifespan, because the cells used to clone her came from a six-year-old sheep - comparatively old in ovine terms. There were also questions about whether the cells' DNA blueprint might have been damaged in those six years, possibly giving rise to cancers.