Doctor Says He Has Cloned Human Embryo
LONDON (Reuters) - A maverick U.S.-based fertility expert said on Saturday that he had transferred a cloned human embryo into a woman but leading scientists immediately expressed skepticism, saying it was highly unlikely.
Dr. Panos Zavos told a stunned news conference in London the embryo had been transplanted at an undisclosed location less than two weeks ago and that he was still waiting to see if it had implanted successfully.
"We transferred the first cloned embryo into a 35-year-old woman. Since it has not been two weeks since we transferred the embryo, we are waiting for the results of the pregnancy," he said.
Zavos traveled from the United States to Britain, where human reproductive cloning is banned, to make the announcement. British Health Secretary John Reid denounced the claim which drew criticism from many quarters, including the Vatican (news - web sites).
Scientists doubted that Zavos had cloned a human embryo and challenged him to produce scientific evidence and to publish his results in a scientific journal so they could be reviewed by experts.
"It is highly unlikely that he has successfully made a cloned human embryo," Professor Chris Higgins of Britain's Medical Research Council (MRC) told Reuters. "So far he has produced no data at all."
Peter Braude, a fertility expert at King's College London said: "Zavos does not represent mainstream science and what he and his colleagues are doing is seeking publicity rather than advancing science."
"IRRESPONSIBLE AND IMMORAL"
The European Society of Human Reproduction and Embryology (ESHRE), which represents 4,000 fertility experts around the world, condemned the cloning claim.
"It is totally irresponsible and unethical to attempt human reproductive cloning. Apart from the ethical objections, which are serious enough, there are major practical problems, not least of which is the high chance of abnormal babies -- even if those abnormalities are not apparent at birth," said ESHRE chairman Professor Arne Sunde.
Research on animals has shown that cloned embryos often do not survive to produce a live birth. Sometimes they die shortly after birth or they can develop serious health problems later in life.
Zavos has been saying since May 2002 that he was ready to try to create a human clone. Last October he said he was only weeks away from implanting a cloned embryo in a surrogate mother but leading fertility experts dismissed the claim.
His former colleague, Italian fertility doctor Severino Antinori, said nearly two years ago that three women were pregnant with clones. He produced no evidence.
The Raelian Movement, a cult that believes life on Earth was engineered by visitors from outer space, a year ago said it had produced the world's first cloned human but it never produced any scientific proof.
Zavos said the embryo he had transferred was from an unidentified woman who was entering premature menopause. He says the egg was harvested from her body and fertilized with DNA taken from skin cells donated by her infertile husband.
Dolly, the world's first cloned mammal, was created by a technique called nuclear transfer. The genetic material from an adult cell was transferred to an unfertilized egg where the original nucleus had been removed. An electric current was used to fuse them together.
Cloning creates an identical copy of an organism by copying its genetic material. It took 277 reconstructed eggs to produce Dolly.
Zavos said he was optimistic but admitted that the chances of the woman's pregnancy going to term were slim. He said he would continue until he had success and added he was looking for more volunteers.
Sat Jan 17, 2:48 PM ET
By Patricia Reaney and Jeremy Lovell
Dr. Panos Zavos told a stunned news conference in London the embryo had been transplanted at an undisclosed location less than two weeks ago and that he was still waiting to see if it had implanted successfully.
"We transferred the first cloned embryo into a 35-year-old woman. Since it has not been two weeks since we transferred the embryo, we are waiting for the results of the pregnancy," he said.
Zavos traveled from the United States to Britain, where human reproductive cloning is banned, to make the announcement. British Health Secretary John Reid denounced the claim which drew criticism from many quarters, including the Vatican (news - web sites).
Scientists doubted that Zavos had cloned a human embryo and challenged him to produce scientific evidence and to publish his results in a scientific journal so they could be reviewed by experts.
"It is highly unlikely that he has successfully made a cloned human embryo," Professor Chris Higgins of Britain's Medical Research Council (MRC) told Reuters. "So far he has produced no data at all."
Peter Braude, a fertility expert at King's College London said: "Zavos does not represent mainstream science and what he and his colleagues are doing is seeking publicity rather than advancing science."
"IRRESPONSIBLE AND IMMORAL"
The European Society of Human Reproduction and Embryology (ESHRE), which represents 4,000 fertility experts around the world, condemned the cloning claim.
"It is totally irresponsible and unethical to attempt human reproductive cloning. Apart from the ethical objections, which are serious enough, there are major practical problems, not least of which is the high chance of abnormal babies -- even if those abnormalities are not apparent at birth," said ESHRE chairman Professor Arne Sunde.
Research on animals has shown that cloned embryos often do not survive to produce a live birth. Sometimes they die shortly after birth or they can develop serious health problems later in life.
Zavos has been saying since May 2002 that he was ready to try to create a human clone. Last October he said he was only weeks away from implanting a cloned embryo in a surrogate mother but leading fertility experts dismissed the claim.
His former colleague, Italian fertility doctor Severino Antinori, said nearly two years ago that three women were pregnant with clones. He produced no evidence.
The Raelian Movement, a cult that believes life on Earth was engineered by visitors from outer space, a year ago said it had produced the world's first cloned human but it never produced any scientific proof.
Zavos said the embryo he had transferred was from an unidentified woman who was entering premature menopause. He says the egg was harvested from her body and fertilized with DNA taken from skin cells donated by her infertile husband.
Dolly, the world's first cloned mammal, was created by a technique called nuclear transfer. The genetic material from an adult cell was transferred to an unfertilized egg where the original nucleus had been removed. An electric current was used to fuse them together.
Cloning creates an identical copy of an organism by copying its genetic material. It took 277 reconstructed eggs to produce Dolly.
Zavos said he was optimistic but admitted that the chances of the woman's pregnancy going to term were slim. He said he would continue until he had success and added he was looking for more volunteers.
Sat Jan 17, 2:48 PM ET
By Patricia Reaney and Jeremy Lovell