The #1 source for news about monkeys and apes

[<ugarte AT rickblaine.com>]

Scientists create first cloned embryo from primate 
http://news.yahoo.com/s/afp/20071114/sc_afp/healthbiotechcloningprimates

PARIS, Nov 14, 2007 (AFP) - Scientists said Wednesday they had created 
the world's first cloned embryo from a monkey, in work that could spur 
cloning of human cells for use in medical research. 

In a paper published online by the British journal Nature, a team in 
the US said they had created cloned embryos of rhesus macaques, using 
the same method that famously led to Dolly the Sheep and other 
genetically duplicated animals.

It is the first time that this technique has been successfully used to 
create cloned primate embryos.

The group generated two lines of embryonic stemcells from the embryos, 
according to the research headed by Shoukhrat Mitalipov of the Oregon 
Health and Science University in Beaverton, Oregon.

Dolly, the world's first cloned animal, was created in 1996, by using 
so-called somatic cell nuclear transfer (SCNT) in which the genetic 
core of an egg is removed and replaced with the nucleus of an adult 
cell.

The egg is then stimulated with chemicals or a jolt of electricity to 
prompt its division.

The list of other cloned creatures using SCNT includes mice, pigs, 
cats, cows and dogs.

Until now, though, there has been no cloned primate, for researchers 
encountered obstacles that caused cell development to be 
catastrophically flawed.

Work on primate cloning has also stirred controversy among ethicists, 
who say it could open the door to cloning human beings, not just 
cells. In an exceptional move, Nature said it moved forward the 
release of the paper because of "continuing speculation" about the 
research.

Researchers distinguish between "reproductive cloning" of humans, in 
which a cloned baby would be born and "therapeutic cloning" in which 
only cloned cells would be used for medical reasons and no baby would 
result.

Helen Wallace of Genewatch UK, a British group that monitors cloning 
and other activities in biotechnology, said the breakthrough announced 
on Wednesday would cause "a real worry" in some quarters that it would 
tempt a renegade scientist to create a cloned baby.

"The clear risk of an experiment [in human reproductive cloning] is of 
a deformed baby and maternal suffering," she told AFP in a phone 
interview.

"In Britain, we don't think that the technology is going to go that 
far because there are laws against reproductive cloning," she said. 
"However, in most countries around the world, there are no legal 
safeguards."

Stemcells are immature cells that develop into the specific tissues of 
the body.

Embryonic stemcells have the highest capability of all, because they 
can differentiate into any tissue. Scientists hope to be able to coax 
these cells into one day becoming replacement tissue for organs that 
are damaged or diseased.

Transplanted cells from a donor, however, run the risk of being 
attacked as intruders by the patient's immune system. By creating 
stemcells that are programmed with the patient's own DNA the risk of 
rejection would be skirted.

Mitalipov's team said they collected 304 eggs, also known as oocytes, 
from 14 female rhesus macaques.

The donor nucleus came from skin cells taken from an adult male monkey 
housed at the Oregon National Primate Research Center. 

Thirty-five blastocysts, or early-stage embryos, resulted from the 
SCNT operation. They in turn led to two lines of self-dividing 
embryonic stemcells -- a success rate of 0.7 percent when compared to 
the number of eggs used. 

"Our results represent successful nuclear reprogramming of adult 
somatic cells into pluripotent ES (embryonic stem) cells and 
demonstrate proof-of-concept for therapeutic cloning in primates," the 
paper said. 

Wallace criticised what she said was the "very high failure rate" of 
SCNT. 

The technique has always needed large numbers of eggs to be harvested 
in order to result in just a small number of cloned embryos. In 
addition, many cloned animals are born with genetic defects and die 
prematurely. 

"We have concerns about the implications of using this technology 
because the failure rate raises questions as to whether the suffering 
in animals is justified," said Wallace. 

The claim that the stemcells were an exact DNA copy of the donor 
monkey's genetic code was validated independently by a team led by 
David Cram of Monash University in Melbourne, Australia. 

That confirmation comes on the heels of a scandal surrounding earlier 
claims on cloning. 

In 2004, South Korean scientist Hwang Woo-suk announced he had created 
30 cloned human embryos from which he derived stemcells, but his data 
turned out to be fake.