ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Sunday, February 23, 1997 TAG: 9702240117
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
SOURCE: The New York Times
IN A BREAKTHROUGH, researchers used a cell from a sheep to make a genetically identical adult.
In a feat that may be the one bit of genetic engineering that has been anticipated and dreaded more than any other, researchers in Britain are reporting that they have cloned an adult mammal for the first time.
The group, led by Dr. Ian Wilmut, an embryologist at the Roslin Institute in Edinburgh, has created a lamb using DNA from an adult sheep. Their achievement shocked leading researchers who had said it could not be done.
In theory, researchers said, the same techniques could be used to take a cell from an adult human being and use the DNA to create a genetically identical human - a time-delayed twin. That prospect raises the thorniest of ethical and philosophical questions.
Wilmut's experiment was simple, in retrospect. He took a mammary cell from an adult sheep and prepared its DNA so it would be accepted by an egg from another sheep. He then removed the egg's own DNA, replacing it with the DNA from the adult sheep by fusing the egg with the adult cell. The fused cells, carrying the adult DNA, began to grow and divide, just like a perfectly normal fertilized egg, to form an embryo.
Wilmut implanted the embryo into another ewe; in July, the ewe gave birth to a lamb, named Dolly. Though Dolly seems perfectly normal, DNA tests show that she is the clone of the adult ewe who supplied her DNA.
``What this will mostly be used for is to produce more health care products,'' Wilmut told the Press Association of Britain early today, according to the Reuters news agency.
``It will enable us to study genetic diseases for which there is presently no cure and track down the mechanisms that are involved. The next step is to use the cells in culture in the lab and target genetic changes into that culture.''
Simple though it may be, the experiment, to be reported Thursday in the British journal Nature, has startled biologists and ethicists. Wilmut said he was interested in the technique primarily as a tool in animal husbandry, but other scientists said it had opened doors to the unsettling prospect that human beings could be cloned as well.
``It's unbelievable,'' said Dr. Lee Silver, a biology professor at Princeton University who said the announcement had come just in time for him to revise his forthcoming book - the first chapter no longer will state that such cloning is impossible.
``It basically means that there are no limits,'' Silver said. ``It means all of science fiction is true. They said it could never be done and now here it is, done before the year 2000.''
Dr. Neal First, a professor of reproductive biology and animal biotechnology at the University of Wisconsin, said the ability to clone dairy cattle could have a bigger impact on the industry than the introduction of artificial insemination in the 1950s, a procedure that revolutionized dairy farming. Cloning could be used to make multiple copies of animals that are especially good at producing meat or milk or wool.
The problem with earlier cloning attempts, Wilmut said, was that the DNA from the donor had been out of synchronism with that of the recipient cell. The solution, Wilmut discovered, was to, in effect, put the DNA from the adult cell to sleep, making it inactive by depriving the adult cell of nutrients. When he then fused it with an egg cell from another sheep - after removing the egg cell's DNA - the donor DNA took over as though it belonged there.
Wilmut said that the method could work for any animal and that he hoped to use it next to clone cattle.
Although the U.S. government prohibits government dollars from being spent on human cloning research, and ethicists decry it, nevertheless it could be done, First said.
First, who pioneered a different method of cloning animals that uses embryonic cells instead of body cells, said that unlike some European countries, the United States has no laws banning human cloning research.
So, if a wealthy person wanted to clone himself, theoretically it could be done, he said.
The National Advisory Board on Ethics in Reproduction, which is supported by federal and private funds, studied human cloning and concluded that it had no merit for human society, said First, a member of the board.
Basically, there are no good reasons to clone human beings. A duplicate body does not mean a duplicate person. The clone's brain would be far different from that of the donor, as it must start from scratch and build its own world of experiences. A cloned Hitler, for example, might turn out to be a philanthropist.
But cloning's potential for agriculture could be far greater than any other technology so far developed, First said.
LENGTH: Medium: 87 linesby CNB