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Cloning a Comeback?

By Rick Weiss
Washington Post Staff Writer
Sunday , October 8, 2000 ; Page A01


Bessie, an ordinary cow on an Iowa farm, is pregnant. But she's not having a
cow. Developing inside her uterus is an endangered species called an Asian
gaur, a heavily muscled, humpbacked, ox-like animal native to the bamboo
jungles of India and Burma.

Bessie's gaur, named Noah and due to be born next month, was cloned from a
single skin cell taken from a dead gaur, researchers report in a landmark
scientific paper in the latest issue of the journal Cloning, to be released
this week.

It is the first endangered species ever to be cloned, and the first cloned
animal to gestate in the womb of another species.

Noah's fetal heartbeat heralds the beginning of a new era of wildlife
conservation in which endangered and even recently extinct animals may make
dramatic comebacks through cloning techniques.

Already, the Massachusetts scientists who created Noah are laying plans to
clone endangered giant pandas, including perhaps the National Zoo's
Ling-Ling
and Hsing-Hsing, who died in 1992 and 1999 and whose cells sit frozen in
liquid nitrogen in Frederick.

Later this year, they intend to clone a species of Spanish mountain goat
that
was listed as endangered until nine months ago, when the last known
individual died. Some of that goat's cells were preserved, and if
researchers
manage to clone new goats from those cells, they will have accomplished the
world's first resurrection of an extinct species.

Extinction, it seems, may not be forever after all.

"It's not science fiction. It's real," said Robert Lanza, vice president of
medical and scientific development at Advanced Cell Technology (ACT), the
Worcester, Mass., company behind the cloning projects.

"One hundred species are lost every day, and these mass extinctions are
mostly our own doing," Lanza said. "Now that we have the technology to
reverse that, I think we have the responsibility to try."

Not everyone agrees. Some fear that a movement to mass-produce endangered
species could compete with global efforts to preserve those animals'
habitats, or lead to the creation of herds and flocks that lack the genetic
diversity so important to species survival.

The more radical prospect of bringing back extinct animals, be they Spanish
goats or dodo birds, raises even more profound environmental and ethical
questions. Would it be right, for instance, to bring back a species whose
native habitat is gone or so fractured that the creature could survive only
in a zoo?

Lanza and his colleagues do not take such questions lightly. They are avid
supporters of environmental preservation and have qualms about using cloning
to reach too far back in time, a la "Jurassic Park."

But at a minimum, they and many other wildlife scientists say,
conservationists around the globe ought to be freezing clonable cells from
all the species they can, as an insurance policy against a bio-impoverished
future. And people should start thinking about the pros and cons, these
scientists say, of sharing the planet with some replicated wildlife.

"Society should reflect and consider carefully the potential of this
technology and its application, and what it can accomplish and what it
cannot," said Oliver Ryder, a geneticist at the San Diego Zoo's Center for
Reproduction of Endangered Species. The center has long focused on
traditional captive breeding programs and habitat conservation, but lately
it
has begun to build up a massive "frozen zoo" of preserved cells as well.

Bessie and Noah offer the first living proof that cloning could play an
important role in species preservation. As described in this week's report
in
Cloning--and more broadly in the upcoming November issue of Scientific
American--Lanza and his colleagues started with 692 skin cells taken from a
recently deceased male gaur. The team fused the cells to cows' eggs whose
own
genes had been removed--a process that creates embryos genetically identical
to the donor gaur.

Nurtured in laboratory dishes, 81 of those gaur embryos grew large enough to
be transferred to the wombs of surrogate mothers. But because gaurs are too
precious to use as experimental subjects, the researchers turned to closely
related stand-ins, in this case 32 domestic cows.

Eight of those cows retained their embryos and became pregnant. The
scientists removed two of the fetuses from two cows early in pregnancy for
analysis (they were normal), and five of the pregnancies ended in
miscarriages. Noah, the sole survivor, is due in late November after a
nine-month gestation.

It may be even more difficult to clone pandas, because neither racoons nor
rabbits, which are the panda's closest relatives, would make ideal surrogate
mothers. So Lanza and his colleagues have made arrangements with bear
hunters
in Maine this month to collect large numbers of eggs from fresh black bear
carcasses. They hope to use the bear eggs and panda cells to make panda
embryo clones, then transfer those embryos to captive bear surrogate
mothers.

The researchers are already negotiating with the Chinese government for
access to panda cells, and they hope to get frozen samples of Ling-Ling and
Hsing-Hsing. In a statement released Friday, National Zoo officials said
they
are "always open to new ideas that might advance the long-term survival of
endangered species" but they have "no plans at this time" to provide giant
panda tissue for cloning experiments.

"It's one thing to put a gaur embryo in a domestic cow, which is very
closely
related," said David Wildt, chief of reproductive sciences at the National
Zoo's Conservation and Research Center in Front Royal. "It's much different
to put a giant panda in a black bear. There's been very little work with
embryo transfer in bears."

Wildt favors habitat preservation and captive breeding programs over
dramatic
but failure-prone cloning efforts.

Other critics go further, saying cloning is outright antithetical to true
conservation.

"There is a very hollow echo of a gaur in the birth of that animal to a cow
in Iowa," said Kent Redford, an international program scientist with the
Wildlife Conservation Society in New York. "To say that is a gaur is to
disrespect all gaurs in all the places where gaurs live. That animal will
never live its life in true gaurdom, to wander in the forests of India and
frolic with other gaurs and die and let teak trees grow out of it. That's
the
gaur I'm working to save."

But several other wildlife scientists said they are enthusiastic about the
idea of cloning endangered species. Money for cloning experiments tends to
come from sources other than those that support traditional conservation
efforts, they said, so the new experiments don't really compete with those
programs.

"As scientists in the area of conservation, we're obligated to use as many
tools as we can," said Betsy Dresser, director of the Audubon Center for
Research of Endangered Species in New Orleans, who was the first to create a
gorilla by in vitro fertilization and the first to conduct a cross-species
pregnancy among antelopes by having a spiral-horned eland give birth to an
African bongo.

Cloning may present some novel scientific and ethical challenges, Dresser
conceded. However, she said, "if your only alternative is extinction, I know
what I'd choose."

Supporters also disagree with critics who claim that cloning will lead to
the
creation of homogeneous populations in which every member is a duplicate of
every other.

"I see cloning as increasing, not decreasing, genetic diversity," said
Philip
Damiani, a research scientist at ACT who helped clone Noah and who, like
Dresser, is trying to clone domestic cats--a development that could
facilitate the cloning of endangered African wild cats.

"The gaur we cloned Noah from is dead," Damiani said. "There are only
90-something left in the U.S. zoo breeding population. You can't import live
endangered animals. So genetic diversity is heading for a bottleneck here
unless we intervene."

Because endangered clones will generally have to be born to mothers of a
less
endangered species, the work also promises behavioral scientists the chance
to answer a host of fascinating questions. Will Noah's Midwestern surrogate
mother raise him right? To what extent are the hallmark behaviors of a
species taught by parents, and to what extent are they genetically
programmed?

When she first started transferring embryos from one species to another,
people were up in arms, Dresser said. "People were saying, 'Oh my gosh,
these
animals are not going to know who their real mothers are. They'll be crazy.
They won't know how to grow up.' "

But the evidence so far, she said, is that in closely related species it
doesn't matter much. After what appeared to be an initial shock, for
example,
her eland fully accepted its newborn bongo.

"That eland looked at her bongo and seemed to say, 'Oh my God. I got the
ugliest kid on the block, but it's mine!' "

The eland "raised it beautifully," Dresser said. And when the bongo grew up,
it engaged in normal bongo mate selection behavior and raised a normal
family
of its own.

Plans to bring back species that have already become extinct raise
additional
issues.

Last year, for example, scientists announced they had found a nicely
preserved 20,000-year-old woolly mammoth in the frozen plains of Siberia.
It's not clear where it could live today or what it might eat, but one of
those scientists, Larry Agenbroad of Northern Arizona University in
Flagstaff, said he would like to see it cloned.

"I don't think this is anything less ethical or moral than bringing back
grizzly bears or wolves to areas where they used to be," he said. "This is
not about creating a monster that is going to gobble humans. We're talking
about making a baby elephant."

It's not clear yet whether the mammoth's remains contain enough intact DNA
to
work with. By contrast, cells from the last living Spanish mountain goat,
known as the bucardo, have been meticulously preserved in a high-tech
freezer. That animal, a female named Celia, died in January when a tree fell
on her head in Ordesa National Park in Spain.

In a collaboration worked out with Spanish government officials, Lanza and
local scientists will start creating clones from those cells in the next
month or so using a common ibex as a surrogate mother.

Even if that cloning effort is successful, it will be impossible to
re-create
a breeding population of bucardos, because cells have been preserved from
just one sex. That means a mate will have to be created, Lanza said, and he
and Damiani think they know how to do it.

The ACT team hopes to gain permission from Spanish authorities to use
recently developed molecular techniques to give some of the preserved
bucardo
cells a male chromosome taken from a related goat. Those cells could then be
used to clone male bucardos

If it works, then male and female bucardos--and their naturally born
young--may again leap among Ordesa's craggy limestone slopes.

© 2000 The Washington Post

Cloning is published by Mary Ann Liebert of Larchmont New York.
An electronic sample of that journal can be accessed at :

 http://www.catchword.com/titles/15204553.htm


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