SIGHTINGS


 
Japanese Clone Calves
From Adult Cells -
Humans Already Done?
7-5-98
 
 
TOKYO (AP) -- Two special calves were born Sunday -- the first clones from cells from an adult cow, Japanese scientists reported.
 
The unnamed twins were born exactly two years after Dolly, the British sheep that made history by becoming the first clone of an adult animal.
 
They are the second adult-animal clones -- after Dolly -- and were produced by a similar technique, said Toyokazu Morita, an official of the Ishikawa Prefectural Livestock Research Center, 190 miles northwest of Tokyo.
 
"We have succeeded in producing calves from adult-animal clones, meaning that we can produce calves exactly similar to adult cows," he said.
 
Morita said the new technique would be used to breed better cattle strains with higher-quality beef or greater milk capacity.
 
"I think it's a very important step in the scientific process," said Caird Rexroad, assistant deputy administrator for the U.S. Department of Agriculture's research service. "There have been a few questions about Dolly ... and confirmation would be good."
 
He said the Japanese success was significant primarily because it cloned another species. "It suggests the technique may be generally usable," Rexroad said.
 
Another cloning expert, Robert H. Foote, said, "I suppose you could say that if you can clone sheep and cattle from an adult, then the probability of cloning an adult human being is less remote."
 
Foote, a professor of animal physiology at Cornell University in Ithaca, N.Y., said the latest success has "substantial significance."
 
Cloning an adult means scientists could clone proved animals. For example, adult cows that produce more milk for market could be chosen for cloning instead of relying on the relative uncertainty of cells from a fetus, Foote said.
 
The cow cloning helps discount the possibility that Dolly's success was the result of some unknown characteristic of sheep, Foote said.
 
On Feb. 16, scientists in the United States cloned a calf -- a Holstein named Gene -- but the animal's genes originated in a cell from a 30-day-old fetus rather than an adult cell. The following day, Dutch scientists cloned two calves using the same technique.
 
In the Japanese experiment, researchers took cells from an adult cow and placed them in unfertilized eggs whose own nuclei had been removed.
 
Then two artificially cultivated embryos each were placed into the wombs of five cows last November, Morita said.
 
All five cows became pregnant and one of them gave birth to the twins Sunday, though all were due Aug. 13, Morita said.


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