Scientists warn against human cloning due to defects in animal cloning * Since the cloning of Dolly the sheep, dozens of other animals have already been cloned. Only 3% of cloning attempts were successful
Cloning (genetic duplication) experts warned yesterday of the dangers inherent in human cloning. The words were said at a seminar on human cloning organized by the US National Academy of Sciences, in Washington.
Gynecologists Dr. Panos Zavos and Dr. Severino Antinori were also invited to the meeting, who stated that they intend to begin attempts to clone a human embryo in November. The discussion took place in the shadow of a sharp controversy over human cloning, and at a time when in the USA a legislative process was initiated, the purpose of which was to prohibit any type of
Human cloning.
Scientists told the conference that in the four years since researchers in Scotland announced they had cloned Dolly the sheep, evidence has accumulated to suggest that cloning healthy animals is a more difficult process than expected. According to Prof. Rudolf Jinish, the problems revealed in cloned animals - developmental retardation, congenital heart defects, lung problems and defects in the immune system - "are serious enough to discourage anyone from cloning humans today."
Antinori and Zavos did not back down from their intention to try to provide infertile couples with cloned offspring. Antinori told the Italian newspaper "La Stampa" the other day that 1,300 American couples and 200 Italian couples are interested in participating in a human cloning experiment. In the interviews preceding the gathering, the two promised to present a "detailed plan" that would clarify how the experiment would be carried out. However, in their lecture they refused to give details about the plan, including the names of the scientists involved in the cloning team.
"There doesn't seem to be one thing or just one aspect of development that goes wrong during cloning," Jinish said. "It seems that the cloning process causes random errors in the expression of the genes." According to her, these mistakes can create any number of unexpected problems, at any stage of life.
Prof. Ryuzo Yanagimichi, from the University of Hawaii, said that he cloned mice and followed their development. Some of the cloned mice became very fat, even though they were given the same amount of food as normal mice. "At first the mice looked fine," said Yanagimchi, "and then, at the age equivalent to about thirty years in human life, their weight jumped." From other studies it is known that cloned cows are born with enlarged hearts and lungs that do not develop properly.
In addition to this, there is still not much success in cloning technology. Out of a hundred attempts to breed cattle, only one succeeds. In mice, a little more success is achieved, but the success rates are 3-2%. In the session attended by Antinori and Zavos, Dr. Brigitte Boisillier, who introduces herself as the scientific director of an American cult, the "Ralim", who believes that life was created, also lectured on Earth by "extraterrestrials with deep knowledge of genetic engineering".
Antinor, Zavos and Boisillier, also offer "cloning services" to parents who have lost their children. According to Hermona Sorek, a professor of molecular biology from the Hebrew University, people think that cloning will create a duplicate and bring back dead loved ones, "but it doesn't work that way - we are much more than what is written in our DNA chain."
26/3/2001
Since the cloning of Dolly the sheep, dozens of other animals have already been cloned. Only 3% of cloning attempts have succeeded Four years after scientists in Scotland shocked the world when they announced they had successfully cloned a sheep named Dolly, scientists say today that there is growing evidence that cloning healthy animals is a more difficult task than previously thought. In recent interviews, experts in cloning and developmental biologists expressed concern that the results of cloning cannot be predicted and that the problems it creates are serious enough to stop anyone thinking of cloning a human being.
Only less than 3% of all cloning attempts are successful. According to the scientists, the cloned animals often suffer from problems such as developmental delays, heart defects, lung function problems and immune system dysfunction. The scientists add that the problem does not focus on a particular organ or aspect. The cloning process creates random errors in the expression of individual genes. These mistakes may produce an unknown number of problems at each stage of the creature's development.
Before the debut of Dolly the sheep in 1997, scientists believed that mammals could not be cloned. But since then sheep, mice, cows, pigs and goats have been cloned. Clones of six generations have already been performed in mice. Two infertility experts recently announced that they want to clone humans.
In the cloning process, scientists take a cell from an adult and transplant it into an egg, after the genetic material has been removed from it. The egg then reprograms the genes of the adult human so that they direct the development of the embryo, which will eventually turn out identical to the human from which the cell was taken. No one knows how the egg reprograms the adult human cells - but this is probably the source of all cloning problems. The problem seems to be that the egg has to do in a few minutes or hours a task that would normally take years. The reprogramming process has to be perfect otherwise the genes may create problems at any stage of development.
Some scientists said they shudder at the thought of what would happen in cloning humans with today's techniques. Until now, the question of human cloning has been treated from its moral aspect, but today some scientists claim that the real issue is the likelihood that cloned humans will suffer from devastating genetic abnormalities. Until this problem is solved, they say, there is nothing to discuss at all about human cloning.
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