Gene Engineers Have Second Thoughts on Cloning

The Observer (UK)
Scientists abandon 'inefficient' cloning

Dolly success proves hard to repeat as vast
majority of experiments end in death or
abnormalities.

Robin McKie
Sunday June 18, 2000

She was always going to be a hard act to follow, an
animal in a million. But now researchers have
discovered that Dolly the sheep, the world's first
cloned mammal, may be even rarer and even more
unusual than first appreciated.

Scientists have found that although other cloned
creatures - pigs, cows, goats and mice - have
been created in the past couple of years, these few
rare successes are proving extremely difficult to
repeat. As one researcher put it: 'Cloning has
turned out to be more art than science.'

In fact, results have been so poor that many
scientists have abandoned attempts to clone
creatures, and are returning to the laboratory to
carry out basic research in an attempt to find out
what is going wrong.

As Professor Keith Campbell, one of the team
responsible for making Dolly, said: 'After we
cloned the first adult sheep, lots of scientists
assumed that it would soon be easy to make
streams of similar clones, that it was just a
matter of honing the technology. But now we are
finding out that it is a lot more difficult than this.
Cloning is turning out to be very expensive and
very inefficient.'

At its heart, the problem involves a host of
different scientific disciplines: in understanding
what types of cell should be used as the founder of
the proposed clone; in selecting the best donor
animals; and in picking the right environments to
grow their cells.

At present, scientists simply do not know the
right criteria for consistently making a clone of
an animal, a problem outlined in the current
issue of the journal Science . It reveals that, even
after a cloned embryo has been made and then
implanted in a surrogate mother's womb, only two
in 100 make it to successful, healthy birth. In the
case of Dolly, it took almost 300 attempts at
implanting an embryo into her surrogate mother
before she became the first healthy cloned lamb to
make it through to delivery .

'Even when an embryo does successfully implant
in the womb, pregnancies often end in
miscarriage,' states the Science report. 'A
significant fraction of the animals that are born
die shortly after birth. And some of those that
survive have serious develop mental
abnormalities, suggesting that something in the
recipe is fundamentally wrong.'

In the case of cloned cattle, more than a quarter
are alarmingly larger than normal and many
abort spontaneously and mysteriously. Even
among those of normal weight, many are found to
have underdeveloped lungs, while others have
dangerously elevated levels of potassium in their
blood. Similar problems affect other species.

'We simply do not know why this is happening,'
said Campbell, of Nottingham University.

Finding out the nature of this fundamental flaw is
now an urgent concern for scientists. However, as
most cloning research is now funded and carried
out by major corporations, their demands for
tight security and secrecy from their staff is
seriously hampering the exchange of data, a point
highlighted by Norton Zinder of the Rockefeller
University in New York. Only a 'major diplomatic
effort' by his staff could persuade leading
scientists in the field to come to a special
conference that was, ironically, aimed at
improving communications in the field.

This failure to crack the fundamental problems of
cloning has several key consequences. For a start,
they suggest that the ethical dilemmas that are
supposed to beset the field must be decidedly less
pressing than previously accepted. As Science
puts it: 'Human cloning - even so-called
therapeutic to produce cell lines to be used in
treating disease - may be a long way off. As for
reproductive cloning, or actually creating living
replica, it would be criminal at this stage in our
abilities.'

Even creating replicas of our favoured pets now
looks a remote prospect, despite the fact that in
the past few months four different US companies
have been set up to create clones from the cells of
dead favourite cats or dogs. For a fee between
£200 and £1,000, one of these companies will
take a tissue sample from your ex-pet and store it
cryogenically for about £100 a year - in
anticipation of the day that scientists crack the
secret of cat cloning or dog duplicating.

'People shouldn't get too excited about this one
either,' said Campbell. 'It will take an awful long
time before we can even consider cloning a cat in a
routine way.'

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"We should be on our guard not to overestimate science and scientific
methods when it is a question of human problems; and we should not assume
that experts are the only ones who have a right to express themselves on
questions affecting the organization of society."

------- Albert Einstein May 1949