World's First Cloned Dog Used to Make More Cloned Dogs So Scientists Can See What Happens

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The world's first cloned dog, Snuppy, was used to create more clones. These are the three surviving dogs cloned from Snuppy's stem cells. Kim et al/Scientific Reports

Scientists have used a cloned dog to create four more dogs in an experiment to find out what happens when animals are re-cloned. The team created the dogs—Afghan hounds—with stem cells from Snuppy, the world's first ever cloned dog, which was born in April 2005.

Snuppy's birth came nine years after that of the first ever cloned animal, Dolly the sheep, but the acheivement was still so ground-breaking that Time magazine named Snuppy one of the most amazing inventions of the year.

Seoul National University has raised Snuppy in an experiment to study the health effects cloning has on animals. The technique is becoming increasingly popular for producing genetically identical and superior animals for use in research and industry, so understanding its effects better is particularly important in these sectors.

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Tai (left) and Snuppy (right). Snuppy became the world's first cloned dog when it was born in 2005. Seoul National University via Getty Images

One of the concerns about cloning is whether or not it causes the aging process to accelerate and results in more health problems for the animal. Dolly died at six after developing a lung disease—about half the age of a regular sheep.

The average lifespan of dogs is between seven and 15 years. For Afghan hounds, the median age is 11.9 years. Tai, the dog that Snuppy was cloned from, lived until it was 12. Snuppy died at the age of 10 while undergoing treatment for cancer.

Reaching this age with no health problems (up until the cancer diagnoses) was considered to be pretty good going by the scientists involved—but they wanted to be sure Snuppy's cancer was related to the dog's genes, rather than it being a clone.

In their latest study, published in Scientific Reports, the researchers from the U.S. and South Korea have taken the original cloning research a step further, creating four more dogs from Snuppy's stem cells. They said any predisposition to cancer within Tai's family could not be determined because all of his litter mates died before the age of eight—long before most cancers normally develop.

"Clinical and molecular follow-up of these reclones over their lives will provide us with a unique opportunity to study the health and longevity of cloned animals compared with their cell donors," the researchers wrote.

One of the four re-cloned dogs died at four days old. However, the other three are now nine months and are all healthy.

"As with Snuppy we do not anticipate that the reclones will go through an accelerated rate of aging or will be more prone to develop diseases than naturally bred animals," the team concluded, adding, "With the data from Tai and Snuppy in hand, we are excited to follow the long-term health and aging processes of these second generation of clones and work with them to contribute to a new era of studying longevity of cloned canines and given the history of both Tai and Snuppy they may also provide potential insights into the development of cancer."