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Cloning experts to tell House committee pros, cons

The cloned mouse on the right became obese as an adult for no apparent reason. Experts say cloned animals often develop abnormalities  

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The mechanics of cloning


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WASHINGTON (CNN) -- In 1997, when the world first heard about Dolly the sheep, the first mammal to be cloned from an adult, the possibility of cloning a human moved from science fiction into the realm of reality. Now Congress is taking up the question of whether human cloning should be allowed.

In a hearing Wednesday, proponents and opponents of human cloning will tell the House Energy and Commerce Committee what they see as the likely consequences of cloning a human being.


In the past year, at least two groups have stepped forward claiming they are ready to clone a human.

Last August, a religious group called the Raelian Movement announced its company, Clonaid, would make the attempt. Former University of Kentucky professor Panayiotis Zavos announced plans in January to clone a human within a year.

Zavos repeated his announcement in Rome, with his partner, Dr. Severino Antinori, the Italian doctor who successfully implanted a fertilized egg into a 62-year-old grandmother nearly seven years ago.

"Trust me, the high risks will be taken care of because we know what we are doing," Zavos said at the Rome conference.

Clonaid's director, Brigitte Boisselier, also is confident.

"I think we have everything we need to proceed now with humans," she said.

Scientists who have cloned other mammals strongly disagree.

"It is not responsible at this stage to even consider the cloning of humans," said Rudolf Jaenisch, a biologist at MIT's Whitehead Institute for Biomedical Research, which has cloned mice.

"At least half, probably about three-quarters, of pregnancies that are generated will be lost," predicted Jonathan Hill, a veterinarian and assistant professor of animal reproduction at Cornell University. Hill has worked with Mark Westhusin, associate professor of veterinary science at Texas A&M University, to successfully clone cattle.

Westhusin will be among those testifying Wednesday before the House committee, joining Jaenisch and Art Caplan, director of the Center for Bioethics at the University of Pennsylvania, to argue that human cloning at this time is not safe. Zavos and Boisselier will testify in favor of cloning.

The mechanics of cloning

To make a clone, scientists first take an egg and remove all of its genetic material. Then the nucleus of a cell -- any cell in the body -- is taken from the individual to be cloned and inserted into the egg. The cell is then given a jolt of electricity to activate cell division, basically tricking the cell into doing what a fertilized egg would normally do. Then the embryo is implanted into a surrogate who carries it to term.

Cloning Dolly wasn't easy. It took 277 attempts before she was born. Cloning cattle has proven equally difficult.

"The biggest problem is maintaining the pregnancy," Westhusin explained. About 90 percent of the embryos die in first trimester.

And calves that make it to term often become sick.

"Their livers, their lungs, their heart, the blood vessels, their placental vessels, and the placenta are often abnormal at birth," Hill said.

He suspects that the fetus may develop normally but the placenta does not, so the fetus is essentially starving. Problems with the placenta may also contribute to another feature of cloned mammals: They're huge.

Hill believes water retention under the skin is a result of poor placental development, resulting in calves being much larger than normal. Fluid retention can also affect the surrogate mother carrying a clone, with 30 to 40 gallons building up in a cow's belly, Hill said.

Researchers have seen similar problems in mice. Clones "may be up to four times bigger than normal animals and the placenta might be up to seven times bigger than in normal animals," Jaenisch said.

Other scientists have observed weight gain in cloned mice long after they are born. Ryuzo Yanagimachi, a biologist at the University of Hawaii, found that when he cloned a certain strain of mice prone to have diabetes, the clones would look normal at birth, but upon reaching puberty -- which, in mice, is after eight weeks -- they gained weight.

Yanagimachi said he doesn't know why the mice gained weight, since they have the same food intake and same amount of exercise as the non-cloned mice.

So far, scientists have successfully cloned sheep, cows, goats, pigs and mice. But the success rate is still very low. According to Yanagimachi, "over a hundred embryos may produce one baby -- and it can have problems -- we don't know why ... we must find this out first in animals."

Zavos and Boisselier disagree. Individually they believe they have the knowledge necessary to produce a human clone now or in the very near future. When Zavos announced his intentions to clone a human, he predicted that he and Antinori could do it within two years.

Boisselier says "we hopefully will have an embryo of this baby by the end of this month or maybe next month."


Both Zavos and Boisselier refer to the vast experience of in vitro-fertilization as the basis for their expected success in cloning a human. Zavos told CNN last month, "I think that 23 years that we've been doing IVF in the human industry we do anywhere from 5 (million) to 10 million eggs retrieved per year, throughout the world ... 200,000 babies are born from such effort yearly."

Boisselier uses a similar argument. "I don't know why we should spend more time on the cows since we already have same level of success as IVF," she said.

Boisselier is a member of a religious group, the Raelian movement, which believes life on Earth was created through genetic engineering by extraterrestrials. She said 50 members of the movement have volunteered to carry the clone of a dead 10-month-old boy. One of these women is Boisselier's daughter, Marina Cocolios, 24.

When asked about the difficulties experienced in animal pregnancies, she maintained she would monitor the embryos and the pregnancies. She admitted there could be some problems, as with any in vitro pregnancy, and if something does go wrong, she said, "we will anticipate to do an abortion."

Zavos also insists the modern techniques of in vitro fertilization will allow him to properly monitor the embryos.

But many scientists and bioethicists disagree.

Art Caplan, director of the Center for Bioethics at the University of Pennsylvania, insisted "if you go to the likes of Dr. Zavos, he will give you a dead baby, a defective baby or a deformed baby. "

"We don't know how to do this," Caplan said.

Jaenisch agreed. "We do experiments with animals and we know there is a major problem, which is not solved, so one should not do this with humans because humans are not guinea pigs," he said.

Neal Furst, professor of animal science at the University of Wisconsin-Madison added, "If you read the animal data carefully, one would be reluctant to go do humans on the basis of the problems that can occur in the pregnancies."

Legally, there's very little to stop scientists from cloning a human. Only four U.S. states -- California, Michigan, Louisiana and Rhode Island -- ban any type of cloning research, both publicly and privately funded.

Currently a federal moratorium bans the use of federal funding for any research that attempts to create a child by somatic cell nuclear transfer -- cloning. Many scientists around the world are abiding by a self-imposed moratorium on cloning humans and several countries have laws that forbid cloning.

Italian doctor defends human cloning
March 22, 2001
Cardinal blasts cloning plans
March 10, 2001

Roslin Institute: Information on Cloning and Nuclear Transfer
PhRMA Genomics: Cloning
International Biorthics Committee
National Human Genome Research Institute
Human Cloning Foundation
Clone Rights United Front
Institute for Philosophy and Public Policy

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