Two others have only the marker gene, Dr. Campbell said. PPL, which sponsored the work, declined to say which human gene was added to the sheep until it publishes the work in a scientific journal. He said that the company announced the birth of the lambs in order to assuage its stockholders, who were peeved by the way the story of Dolly suddenly appeared in the press in February. Dr. Lee Silver, a mouse molecular geneticist at Princeton University, said the speed and the implications of the work were stunning. Biotechnology companies are operating well ahead of ethical concerns.
Cloning is essential to all biotechnology futures.