WE WILL clone humans. That was the blunt message of three renegade scientists
when they confronted top animal cloners and fertility experts in Washington last
week.
The normally sedate atmosphere of the National Academy of Sciences changed
dramatically when Italian fertility specialist Severino Antinori, his colleague
Panayiotis Zavos of the Andrology Institute in Kentucky and Brigitte Boisselier
of Clonaid took the stage. With the world鈥檚 media in attendance鈥攁t one
stage camera crews even pursued Antinori as far as the toilets鈥攊t was more
like a Hollywood event than a staid scientific inquiry.
The trio had been invited to give evidence by the academy, an independent
organisation that is preparing a report on possible uses of cloning technology,
such as growing tissue for transplants. Antinori was an obvious choice, since
his intention to clone humans is well known.
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He is already notorious for pushing the ethical boundaries in reproduction.
On one occasion, he helped a 62-year-old women conceive a child through IVF. On
another, he claimed to have produced babies using human sperm matured in rodent
testes.
Speaking in a thick accent that at times left his audience baffled, Antinori
dismissed any worries about the safety of cloning. 鈥淭herapeutic cloning鈥�, he
said, could be used to treat infertility where no other treatment
existed鈥攆or instance, in men who produce no sperm. Any defective embryos
could be screened out by weekly genetic tests on the embryo and imaging
techniques such as ultrasound on the fetus, he claimed.
Antinori鈥檚 use of the term 鈥渢herapeutic cloning鈥� for fertility treatment
angered other scientists like Jose Cibelli of Advanced Cell Technology in
Massachusetts. As Cibelli later pointed out, the term is usually used to
describe the creation of stem cells for transplant via cloning techniques, not
reproductive cloning. In the US, researchers are fighting to stop this being
banned along with reproductive cloning.
The human cloners鈥� upbeat tone continued when Zavos took the mike. He cited
animal cloning studies in which 30 per cent of implanted embryos produced live
clones. He dwelt on one Japanese experiment in which eight live cows were cloned
from 10 embryos. 鈥淟ike we say in Kentucky, this ain鈥檛 hay, this is 80 per cent,鈥�
he said. 鈥淚n human IVF you get only 30 per cent success, and you are happy if
you do that.鈥�
Strangely, after praising their work, Zavos then began berating the animal
cloners. He singled out for personal attack the creator of Dolly the sheep, Ian
Wilmut of the Roslin Institute, and Rudolf Jaenisch of the Massachusetts
Institute of Technology, who have both spoken out about the perils of attempting
to clone humans.
Many animal clones have life-threatening genetic and physiological problems,
researchers like Wilmut have found. Often the defects only become apparent late
in gestation or soon after birth. For that reason, nearly all experts in cloning
believe it is too early to use the technology to produce a human being.
But Zavos insisted that any health problems in the clones created so far
weren鈥檛 caused by flaws in the technology. 鈥淭hose difficulties are due to poorly
designed experiments, poorly approached experiments and poorly understood and
interpreted experiments, and I have to say that some of them were done for fame
and fortune,鈥� he said. His comments evoked a mixture of gasps and nervous
laughter from the listeners, astounded that Zavos was not only making such
criticisms鈥攈e has yet to clone anything himself鈥攂ut also had the
cheek to attack others for seeking fame and fortune.
Next on was Boisselier. Her company, Clonaid, was founded by a cult called
the Raelian Revolution, which believes that humans were created by
extraterrestrials and that cloning is the way to achieve immortality. She called
for openness among scientists about cloning, but showed no slides, presented no
data and said that since she worked for a private company she couldn鈥檛 discuss
the details of her work.
At one point, she even suggested Clonaid had already created human embryos
through cloning techniques, but later declined to confirm it. She also claimed a
major advance鈥攁 technique to screen individual cells for abnormalities in
the 鈥渋mprinting鈥� of up to 10 human genes. Imprinting can affect gene expression,
and faulty imprinting has been blamed for the abnormalities in clones. 鈥淒o I
have any concern about harm that should be done to a child or to a mother [who]
would carry a cloned child?鈥� she concluded. 鈥淚 do not have any concern.鈥�
Many of the participants wound up frustrated that the would-be cloners
revealed little other than their determination to go ahead, and their ability to
attract the media spotlight. One of the panel鈥檚 moderators, Irving Weissman of
Stanford University, politely pushed them to be more forthcoming: 鈥淚鈥檓 inviting
Drs Antinori, Boisselier and Zavos, if you wish to supply us with some of the
data . . . that informs your judgement, please do so in the next week.鈥�
Even in the little that the three did reveal, there was plenty of grist for
angry exchanges between participants. Jaenisch said the genetic defects in
clones were too subtle and too widespread to be detected as Antinori described.
鈥淭o say you can pre-screen embryos and determine whether a given clone is normal
or abnormal I think is false. The methods don鈥檛 exist,鈥� he said.
Alan Colman of PPL Therapeutics, a Scottish cloning company attached to
Wilmut鈥檚 institute, said that Zavos had interpreted the animal data too
optimistically. For example, Colman pointed out that four of the eight Japanese
cows Zavos was so impressed by had died shortly after birth.
And Boisselier鈥檚 implication that she could already screen out a lot of
defects left many in the audience sceptical, while others dismissed it outright.
鈥淚 don鈥檛 think that is at all possible,鈥� said Alan Trounson of Monash University
in Australia.
But even in this surreal atmosphere, a few snippets of new science emerged.
For instance, there has always been some doubt as to whether cloning really
reprograms the genome of specialised cells or whether the process simply selects
for wayward primitive cells.
Colman told the meeting that his team has started to address this point by
analysing the molecular properties of a single cell from skin before it was
allowed to divide and its progeny successfully used to make clones. 鈥淚t was not
an errant embryonic stem cell,鈥� said Colman.
Another insight came from Jaenisch. Genetic errors that are introduced into
cells as they are cultured in the lab have emerged as a major suspect in the
hunt for the health problem of clones. But Jaenisch revealed preliminary data
that clones derived from cumulus cells, which are never cultured, also have
these problems. So the sources of clone health defects must extend beyond
so-called cell 鈥渃ulture shock鈥�.
Indeed, one theme that emerged at the meeting was how much is still unknown
about cloning. But to Mark Siegler, a doctor and ethicist at the University of
Chicago, it was clear that Antinori, Zavos and Bosselier are not scared of the
unknown. 鈥淚t sounds as if [they] are likely to proceed with cloning humans
despite animal data that raises concerns and worries about it.鈥�
