Report: Cloned sheep has human gene

'Polly' could produce milk with beneficial protein

July 24, 1997

LONDON (CNN) -- The scientists responsible for Dolly the sheep, the first clone of an adult animal, have now produced Polly, who has the added ingredient of a human gene, it was reported Thursday.

The added gene will produce a human protein in Polly's milk which can then be extracted and given to patients who lack it, such as hemophiliacs and bone disease sufferers.

The financial backers of the experiment -- Edinburgh, Scotland-based Roslin Institute and PPL Therapeutics -- are hoping Polly will help make cloning commercially viable.

Proteins derived from Polly and other genetically modified sheep could be in clinical trials by 1999, according to the report in the Financial Times, a London newspaper.

Although sheep with genes from other species have existed for years, Polly is the first one created using cloning technology, the paper said.

Cloning allows for every sheep produced to be female and, therefore, capable of providing milk.

"This is a realization of our vision to produce instant flocks or herds which express high concentrations of valuable therapeutic proteins very quickly," said Alan Colman, PPL's research director.

The report said the human gene was added to the nucleus of a sheep cell taken from an adult sheep, which was then fused with a sheep embryo cell from which the nucleus had been removed. The resulting embryo was then transplanted into a female sheep.

The paper said the Edinburgh scientists also plan to apply the technique to cows, which produce more milk.

Replacing genes in pigs could follow, allowing for the production of animals whose internal organs could be transplanted to humans.