Scientists at an international conference in Washington have announced their intention to begin cloning humans, unleashing a furore in the scientific community over the morality of creating duplicates of living people.
A team of researchers, led by Italian embryologist Dr Severino Antinori, announced yesterday at the US National Academy of Sciences that they would carry out experiments in an effort to help childless couples become biological parents.
Dr Antinori said that he expected to start the experiments by November, using the cloning technology that created Dolly the cloned sheep. A donor egg will be combined with DNA taken from an adult cell to produce an embryo, he told CNN television. "That embryo will be transferred into the uterus to establish a pregnancy."
The Italian Medical Association has already launched disciplinary action against Prof Antinori for his stated plans, which would also violate European cloning guidelines.
Dr Mario Falconi, the vice-president of Rome's medical association, said the professor could be barred from practising in Italy altogether.
Scientists have frequently warned about a multitude of difficulties associated with cloning mammals, including miscarriage, premature delivery, genetic abnormalities and stillbirths. To date, sheep, mice, goats, cows and pigs have been cloned, with dismal results, most dying at various stages of embryonic development or soon after birth.
"The basic biological problem is absolutely similar in all mammals, and humans are mammals," warned Dr Rudolf Jaenisch, a cloning specialist at the Massachusetts Institute of Technology.
But Dr Panos Zavos, a colleague of Dr Antinori, told the conference that exhaustive measures would be taken to ensure human clones would not suffer the kinds of genetic damage common to other cloned mammals.
The researchers said a procedure called pre-implantation diagnosis would be used to test the viability of embryos and foetuses at various stages of development to screen for genetic abnormalities.
Most US infertility organisations have come out strongly against human cloning.