SCIENCE
First Cloned Dog Has Its Day
The arrival of Snuppy, a cloned Afghan hound, heralds both scientific import and deep symbolic significance.
A lot of U.S. researchers are muttering "doggone it" today: South Korean scientists have won the international race to clone a dog. A team led by Seoul National University’s Woo Suk Hwang, renowned for world-leading stem-cell research, reported in the journal Nature today that it has produced two genetic duplicates of a male Afghan hound.
The scientific import of this development is to some extent overshadowed by its political and symbolic importance. To be sure, dog cloning does promise to help scientists study human disease and speed the quest for better therapies in ways that cloning other animals has not. But the announcement is also likely to intensify concern that the U.S. has lost the lead in basic research on stem cells and cloning, two closely linked areas of study in which Hwang’s group has recently made stunning advances. Last year his team was the first to clone early-stage human embryos and extract potent embryonic stem cells from one of them, which is a key step on the way to growing replacement tissues for patients with failing organs.
The Koreans’ achievement also brings home, as few advances have, biology’s power to touch our lives. Animal cloning has become fairly routine. (See slideshow: A Noah's Ark of Cloned Animals) Genetic knock-offs of mice, rats, cats, rabbits, goats, pigs, cows, and horses have been produced since 1996, when Dolly the sheep proved mammals could be cloned. But the dog is the first cloned creature that has served in the military, orbited the earth, starred in movies, and played competitive Frisbee.
U.S. scientists’ failure to win the dog-cloning race wasn’t for lack of trying. In 1997, a crack team at Texas A&M; University launched a high-profile, $4 million dog-cloning project backed by billionaire John Sperling, founder of Apollo Group (nasdaq: APOL) and its subsidiary, the online University of Phoenix. The "Missyplicity project" was aimed at cloning Sperling’s favorite canine, a mutt named Missy. A company that offers pet-cloning services, Genetic Savings & Clone, was born of the project. But so far, no dog. (The closely-held, Sausalito, Calif.-based firm has led the way in cat-cloning, though, generating more buzz per manufactured unit than any company on earth. So far it has cloned two beloved tabbies for customers at $50,000 a piece.)
Genetic Savings issued a terse press release on the Korean first, congratulating its rivals but attributing their win partly to the "greater availability" of dogs for research in South Korea, where animal-protection groups have little sway. "We expect to produce our own canine clones in the near future," it added.
Dogs have proved one of the hardest species to clone. The basic method, used to clone Dolly and other animals including the Afghan hounds, involves placing an adult animal’s DNA, extracted from, say, a skin cell, into an egg cell from the same species that has had its DNA removed. The reengineered ovum is then implanted in a surrogate mother to begin gestation as the genetic twin of the adult DNA donor. The process hasn’t worked well with dogs largely because the species’ fragile egg cells, typically obtained in an immature state from spay clinics, are extremely difficult to mature in the lab, said Texas A&M; cloning expert Duane Kraemer, who in 2001 helped create the first cloned cat, CC. (CC now lives with Kraemer.) His group nearly succeeded three years ago, thoughone of its Missy clones seemed okay in utero but was stillborn, he said.
The Korean team reported that their two cloned dogs resulted from swapping out the DNA in 1,095 egg cells and implanting them in 123 surrogate mothers. Three pregnancies resulted, two of which reached full term. One of the two cloned pups died at three weeks from pneumonia. The lone survivor, dubbed Snuppy, is now 100 days old, said Gerald Schatten, a University of Pittsburgh researcher who advises the Korean team.
The Afghan hound was chosen for the experiment, Schatten added, because of the breed’s distinctive look and docilityimportant qualities for Snuppy, who is likely to become as big a celebrity as Lassie.
But the Korean work will yield more than photo ops. Dog-cloning should pave the way for the ability to clone dog embryos and then to extract embryonic stem cells from them. This procedure has been demonstrated so far only in mice and humans, Schatten noted. Dogs have long been used to test new drugs by pharmaceutical outfits like Merck, Amgen and Pfizer. The industry's familiarity with dogs as research animals make them especially valuable for studies on embryonic stem cells. In particular, it may be possible to extract the potent stem cells from cloned dog embryos and transform them into the multiple cell types needed to create replacement tissues. After such techniques are perfected in dogs, it might be possible to apply them with little change to developing new tissues for human patients.
The ability to clone dogs also opens the door for new kinds of studies on their genes; dogs' metabolic resemblance to humans should make such knowledge highly valuable to medical researchers. For instance, scientists might disable a particular gene in a cloned dog embryo and then observe the effects of the change on fetal development and on postnatal functioning in order to determine what the gene does. Similar DNA tweaking might produce cloned dogs that are genetically predisposed to illnesses such as diabetes, cancer or Alzheimer’s disease. That would give researchers insight into how such scourges unfold, as well as new avenues to test experimental therapies for them.
Cloning dogs with altered genes will also help researchers elucidate the genetic underpinnings of the species’ incredible diversity, answering questions such as why poodles are smarter than bulldogs, and why Chihuahuas live much longer on average than Irish Wolfhounds. Such knowledge would doubtless yield profound insights on our own species, given that dogs, like us, are semi-educable, highly social animals that live a long time compared with most animals.
But the Koreans’ work isn’t likely to enable the commercial cloning of adored Fidos and Fifis anytime soon. Dog-cloning still requires world-class craftsmanship that isn’t yet available to pet owners. Genetic Savings, however, is developing a technology called chromatin transfer that promises to make it easier. The firm’s success remains to be seen. But its feline feats give hopeas that great naturalist Hamlet said, "The cat will mew, and dog will have his day."
Seoul National University’s Woo Suk Hwang a publié le résultat de ses recherches dans ''Nature Magazine'' après avoir réussi à produire le premier chien cloné de l'histoire après la brebis Dolly, les oies, etc.

Le chien, appelé Snoupi, est né le 24 avril. Le problème réside dès lors pour les chercheurs dans les questions éthiques sur le domaine de la recherches sur les embryons de cellules vivantes.

Des companies comme ''Amgen'' s'intéressent à ce type de technologie, comme il est stipulé dans ''Fortune Magazine'' pour faire des recherches pharmaceutiques et pouvoir fabriquer des médicaments pour l'homme car le chien et l'homme souffre des même maladies comme par exemple le diabète.