NOW A COW: CLONED CALF UNVEILED BY DOLLY TEAM

February 24, 1998

LONDON (Reuters) -- The company that helped to clone Dolly the sheep said on Monday that it had also cloned a calf.

"Mr Jefferson," a healthy 98 pound (44.5 kilo) Holstein breed, was born in Virginia on February 16, President's Day in the United States, said PPL Therapeutics chief Julian Cooper.

But unlike Dolly, whose creation a year ago made international headlines and sparked fears that human cloning would not be far off, Mr Jefferson was produced by nuclear transfer from a foetal cell, not from an adult cell line.

"This is an important development. The technique used was similar to that used to produce Dolly and the world's first cloned transgenic lamb, Polly," Cooper said in a statement.

"While the calf is not transgenic (carrying a human gene), we have shown we can do the difficult part, and this success now opens the way to producing transgenic cows using nuclear transfer, Polly having proved the principle," he added.

PPL is one of the world's leading companies in the transgenic production of human proteins for therapeutic use.

Scotland's Roslin Institute and PPL, its commercial partner, announced the arrival of Dolly, the first-ever successful cloning of an adult animal, exactly a year ago.

Although Dolly was born in July 1996, the news of her arrival and the cloning technique was not published until February 1997.

Polly, the world's first transgenic lamb, followed several months later and now scientists have shown they can use the technique to produce cattle.

"From a commercial point of view, the most important feature is the ability to produce small clones of transgenic animals from modified cells. We have demonstrated we can do this with the birth of Polly, and Mr Jefferson shows we have the capability to extend the technique to cattle," explained Dr Ron James, PPL's managing director.

Scientists at the Roslin Institute produced Dolly by taking the nucleus out of a cell from the mammary gland of an adult animal and fusing it, using an electrical current, into another sheep egg cell from which the nucleus had been removed.

Polly had been genetically engineered to carry the human gene for the production of the blood clotting agent Factor IX, which could help hemophiliacs. The company hopes the sheep milk will be a cheaper source of Factor IX and one free from any infection.

PPL has also used genetically engineered sheep to produce alpha-1-antitrypsin (AAT), a human protein used to treat cystic fibrosis patients, in their milk. They are currently testing it in human volunteers.

The scientific euphoria over Dolly was dampened recently when some scientists questioned whether Dolly was really a true clone.

Ian Wilmut, the scientist at Roslin which led the team that produced Dolly, denied the claims and said he would prove it by comparing cells frozen from the ewe which provided Dolly's genes and cells taken from her.