Scientists said on 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 journal Nature, a United States-led team said it had created cloned embryos from rhesus macaques using the same method that created Dolly the Sheep and other 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 stem cells 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). Under it, the genetic core of an egg is removed and replaced with the nucleus of an adult stem 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, as researchers encountered obstacles that caused cell development to be flawed.
Work on primate cloning has stirred controversy that it could open the door to cloning human beings.
In an exceptional move, Nature said it was moving forward release of the paper because of ”continuing speculation” about the research, following media reports at the weekend.
Researchers distinguish between ”reproductive cloning”, in which a putative cloned baby would be born, and ”therapeutic cloning”, in which only cloned cells would be used, for medical reasons, and no baby would result.
Stem cells are immature cells that develop into the specific tissues of the body.
Embryonic stem cells 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, though, run the risk of being attacked as intruders by the patient’s immune system. By creating stem cells that are cloned with the patient’s own DNA, the risk of rejection would be skirted. — Sapa-AFP