http://www.time.com/time/health/article/0,8599,1147490,00.html
Cloned Canine Proves Legitimate
Cloned Canine Proves Legitimate
Dr. Woo Suk Hwang has come under fire for fraudulent research, but Snuppy, his cloned pup, stands up to scrutiny
By ALICE PARK AND STELLA KIM
Posted Monday, Jan. 09, 2006
Although South Korean stem cell researcher Woo Suk Hwang has had to admit to serious flaws in his ground-breaking studies on human stem cells, he can still claim credit for one feat—creating the world's first cloned dog.
DNA testing of Snuppy, Time's Invention of the Year for 2005, confirmed that he is a genetic copy of Tai, the male Afghan hound whose skin cell Hwang cloned to create the cloned pup. The results were announced on Tuesday by a nine-member panel at Seoul National University (SNU), where Hwang is a professor of veterinary medicine. All of Hwang's work, including Snuppy, has come under question after he was forced to retract a paper on his human embryonic stem cell studies amid allegations that he manipulated data, and had not generated the stem cells as was described in two ground-breaking scientific publications.
These latest results confirm preliminary analysis commissioned by Hwang's team—independent of the SNU panel—that was released two weeks ago. The university committee, made up of both professors and outside consultants, hired three independent labs, based in Seoul, to conduct the testing, and all confirmed that Snuppy and Tai's nuclear DNA matched. Matching nuclear DNA, however, is only the first step to verifying a clone. Animal cells contain two separate sources of DNA—the nucleus, which provides the core genetic blueprint, and the mitochondria, which adds genes important for generating the energy cells need for important metabolic functions such as respiration. Normally, both egg and sperm add nuclear genes to a new embryo, while mitochondrial DNA can only be passed down as part of the egg's genetic contribution. As a clone, however, Snuppy was created after Tai's nuclear genetic material was inserted into an egg, from another canine donor, whose nucleus had been removed. That egg retained its own mitochondrial DNA, but now had a new set of nuclear genetic instructions. And it was then stimulated to divide and mature into what eventually became Snuppy. Consequently, Snuppy and Tai should have identical nuclear DNA but should not have the same mitochondrial genes. And that's what the testing labs found.
“Results from our analysis of 27 markers that allow distinguishing amongst extremely inbred animals, and of mitochondrial sequencing, indicate that Snuppy is a somatic cell clone of Tai,” the panel said in its report.
It's a small victory for the beleaguered Hwang, whose discredited studies have left his scientific reputation in shambles, but it does validate his claim that despite significant flaws in the way he conducted some of his studies, he had made some contributions to the field of cloning and stem cell technology.