SIOUX CITY, Iowa, April 8 (UPI) -- One of the two offspring cloned from an endangered species last week developed health problems and had to be euthanized, scientists reported Tuesday.
The San Diego Zoo, and Advanced Cell Technology Inc., of Worcester, Mass., had announced Monday they successfully created two cloned offspring of a type of endangered wild cattle called a Banteng. The goals of the project were to reintroduce genes from a captive Banteng that had never reproduced and to advance further the potential of cloning as a technique to save species on the brink of extinction.
The first calf, born last Tuesday, was normal weight for a Banteng newborn at 40 pounds and appears to be healthy.
However, the situation looked dire from the beginning for the second calf, which was born Thursday.
The animal suffered from large-offspring syndrome, a common problem seen in cloned animals. It weighed about 80 pounds at birth, double the normal weight. The animal also appeared sluggish and not as active as the first calf.
"The veterinarians made the decision to euthanize the calf early this afternoon," Eric Woolfson, spokesman for Trans Ova Genetics in Sioux City, Iowa, where both the animals were born, told United Press International.
"It had been struggling ... and the vets made that decision for humane reasons," Woolfson said.
Further details about the health condition of the animal were not available. Woolfson noted an autopsy will be conducted but added it probably will be a couple of weeks before the results are made available.
"The first animal continues to be up and active and doing well," he said.
Dr. Robert Lanza, vice president of medical and scientific development at Advanced Cell, still reeling from hearing the news just moments before, told UPI the euthanization does not affect the success of the project.
"One (successful clone) is enough to resurrect those genes that would've been lost," Lanza said.
"When we did this, the goal was to generate one or two healthy animals ... so this is about exactly how we would've anticipated it would've worked out," he said.
Aside from cloning, the first month is always critical for reproduction of an endangered animal so the surviving clone will continue to be monitored very closely for the next few weeks.
The project began three years ago when Advanced Cell approached the San Diego Zoo about cloning endangered species.
The Zoo provided a vial of frozen cells that had been obtained from the bovine Banteng some 25 years ago. As first reported by UPI last August, scientists at Advanced Cell transferred the DNA from skin cells from the animal into egg cells of ordinary domestic cows.
These were then developed into embryos in the laboratory and then implanted into the wombs of surrogate cow mothers. Only two of the 16 pregnancies made it to term and now only one of those births has survived.
Lanza described the baby Bantengs as "adorable," saying they "look like little Bambis with big brown eyes and ears."
The first one is still doing well, he noted. "This thing is bouncing all around so it's quite happy. That one couldn't be doing any better," he said.
Advanced Cell made history in 2000 when it announced the first successful cloning of an endangered species, a type of wild ox called a Guar. However, the animal died just two days after birth from dysentery.
That experience may have aided the survival of the cloned Bantengs, Lanza said. The cloned Guar would not suckle initially and so the caretakers force-fed it milk. That may have caused the milk to ferment in the stomach, which in turn could have led to dysentery.
This time around, they worked very carefully to get the animals to suckle on their own, Lanza said. Cow's milk was used to feed the Banteng babies.
The surviving clone will eventually be transported to the San Diego Zoo, where it will be integrated with their herd of Bantengs.
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(Reported by Steve Mitchell, UPI Medical Correspondent, in Washington)
