US scientists euthanize cloned baby banteng

[Guest guest]

US scientists euthanize cloned baby banteng

------

 

USA: April 11, 2003

 

 

WASHINGTON - One of a pair of cloned bantengs, a rare species of Asian

cattle, has been euthanized because it was abnormally large, its creators

said.

 

 

 

The banteng calf was born twice the normal size, a common cause of death in

cloned animals, said Dr. Robert Lanza of Massachusetts-based Advanced Cell

Technologies.

 

" The second animal we euthanized yesterday, " Lanza said in a telephone

interview. " A banteng should only be 40 pounds (20 kg). The first calf

weighed 40 pounds (20 kg) but the second was 80 pounds (36 kg), almost twice

what is normal. "

 

Despite this, the larger calf looked healthy at first. " It was snuggling and

then it took a nosedive. The vets at the zoo decided for humane reasons that

it should be euthanized, " he said.

 

The two bantengs were cloned from the San Diego Zoo's " frozen zoo, " a

project launched before anyone knew whether cloning would work. Bantengs,

enormous cattle that once thrived in the dense forests of Indonesia,

Myanmar, Malaysia and elsewhere in southeast Asia, are now endangered.

 

The zoo, working with cloning leader ACT, hoped to resurrect a male that

died in 1980 without ever breeding. They want to use his genes to breathe

new life into the inbred gene pool of captive bantengs, Lanza said.

 

The experiment, a collaboration including ACT, the San Diego Zoo, Iowa State

University and Trans Ova Genetics, worked in part because bantengs are

closely related to domestic cattle, said Lanza. They cloned frozen cells

from the long-dead banteng using cow eggs, and used a domestic cow as the

surrogate mother.

 

Cloning is fraught with problems and Lanza said the calf's abnormalities did

not come as a surprise.

 

" You don't ever know with cloned animals - the first few days are crucial, "

Lanza said.

 

The process of cloning can lead to an abnormal placenta - the organ that

nourishes a developing embryo and fetus. Many cloned animals have been born

large, and this in turn can lead to fatal heart conditions and failures of

other organs.

 

" It not uncommon at all in cloning. It is called large calf syndrome, " said

Lanza.

 

It is also one of the reasons that most cloning experts are reluctant to

ever try cloning a human being.

 

Wildlife groups have spoken out against the experiment, saying the best way

to preserve a species is to save or resurrect its environment and allow

breeding populations to re-establish.

 

" Until the threats that caused a species to become endangered in the first

place - poaching, habitat loss, loss of prey base - are addressed, creating

animals in the lab doesn't solve the problem, " said Jan Vertefeuille, a

spokeswoman for the World Wildlife Fund.

 

But Lanza said this was not the intention of the zoo, which wanted to

preserve captive populations of bantengs. " The goal here wasn't to get a

clone per se but to get the genes back into the population, " he said.

 

 

Story by Maggie Fox, Health and Science Correspondent

 

 

 

REUTERS NEWS SERVICE