Snuppy the Afghan hound, the world’s first cloned dog, died 13 days after his 10th birthday in 2015, but his genetic legacy lives on in his three reclones. Scientists cloned the original clone in order to gain a better understanding of how the health and lifespan of cloned animals compare to those of their cell donors. So far, the results of cloning research have been mixed, as some individuals end up like Dolly the sheep, who died after half a normal sheep life at six years of age. But Snuppy’s case is a bit more promising.
His story is told by a team of veterinary researchers at Seoul National University, the University of Illinois at Urbana-Champaign, and Michigan State University that published some of the first descriptions of clones-of-a-clone on November 10 in the journal Scientific Reports. In an article titled “Birth of clones of the world’s first cloned dog” (try saying that five times fast), these scientists described the process by which they successfully cloned the world’s first cloned dog and followed up on the resulting puppies’ health.
Four of Snuppy’s clones were born at normal weights, but one died four days after birth from severe diarrhea whose cause was never confirmed. This neonatal mortality, the scientists write, falls within normal expected ranges for dogs. Otherwise, Snuppy’s clones are doing great.
“At the time of writing this report, the other three reclones are 9 months of age, of similar weights and remain healthy,” wrote the study’s authors.
Snuppy’s somatic cell donor, Tai, died at 12 years of age. He was a companion dog, and his owner had him euthanized after a cancer diagnosis. Snuppy, in contrast, lived his life as a lab animal at Seoul National University (hence his name). The median lifespan of Afghan hounds is 11.9 years, so both dogs lived to within a reasonable margin of that number. The fact that both died from cancer is not that surprising and not necessarily linked to their clone nature, given the fact that 27 percent of purebred dogs die from cancer and 45 percent of dogs over 10 years old die from cancer.
“Despite the different housing environment, Snuppy lived a life that is similar to its cell donor Tai and did not exhibit any health problems until being diagnosed with T-cell lymphoma at 9 years of age,” the study’s authors wrote. Because Tai’s littermates all died before age 8, when dogs usually start developing cancer, the researchers could not plumb his genetic heritage for cancer risks.
In the quest to advance animal cloning for lab animals, industrial agriculture, and even replacing companion animals, scientists are eager to figure out how clones’ health compares to donors’. Starting with Dolly, who died from infectious disease and was therefore not a good comparison point, the scientific literature has been rather thin on this point. This research aims to beef it up with a detailed record of Snuppy’s clones.
“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,” the researchers concluded.