Cloning man's best friend, though, has proven more difficult than cloning farm animals. The researchers said canine eggs are hard to work with, because they are released from the ovary earlier than in other mammal species.
The project took the research team less than three yearsa fast accomplishment, considering that the Genetic Savings and Clone company, has struggled to duplicate a dog, named Missy, since 1997.
"Although we had hoped to be first to produce a cloned dog," the Sausolito, California-based company said in a written statement. "Most of our research is geared toward development of the next-generation technologies required for commercialization, especially high-throughput ova assessment and maturation [in other words, more succesful clones from fewer eggs], which the South Koreans cite as a key bottleneck to canine cloning."
The company believes it will produce a canine clone this year and that the method it now uses, called chromatin transfer, will result in better efficiencies and health outcomes than the conventional nuclear-transfer method used by the South Korean scientists.
The multimillion-dollar Genetic Savings and Clone project is funded by Missy's owner, Arizona entrepreneur John Sperling. The husky mix died in 2002, but her tissue samples have been saved for cloning.
While dogs have been elusive for Genetic Savings and Clone, cats are a different story. In 2002 the company produced the first copied cat and last year began offering its service to the public.
$32,000 to Clone a Cat
So far, five cats have been cloned commercially. The current cost for the service is U.S. $32,000.
Hwang says the university has no plans to produce dogs for individual owners. Instead, his future research plans involve treating hereditary disorders in dogs as well as studying human genetic diseases and certain canine diseases.
"Eventually, our cloning technology may be utilized for cloning service animals, such as guide dogs, and search-and-rescue dogs," he said. "Perhaps this cloning technology could even be applied to the preservation of endangered species."
News of the bioengineering breakthrough had some people growling.
Crystal Miller-Spiegel is a senior policy analyst for the American Anti-Vivisection Society (AAVS), based in Pennsylvania. She voiced concerns about the welfare of animals used in cloning experiments, which involve multiple invasive procedures.
"Animal cloning is consistently inefficient and leads to grave animal suffering," she said.
Earlier this year AAVS tried to get a bill passed in California to ban the sale of cloned and genetically modified pets.
The organization also petitioned the U.S. Department of Agriculture to require cloning companies to be licensed, like it does research laboratories. Licensing would make cloning companies adhere to federal standards of humane care and treatment of animals, as well as require periodic inspections.
Both attempts failed.
The California bill, however, is still active and will be reconsidered in the next legislative session, Miller-Spiegel said. If passed, it will be the first of its kind in the United States.
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