Clones of Cloned Sheep Aging Normally

Dolly the sheep was the world’s first cloned animal to survive to adulthood, while 277 other attempts failed. She was born 20 years ago, and lived for six and a half years. When she died of a not-uncommon sheep lung disease, there was some speculation that Dolly might have been suffering the effects of old age because she was cloned from a six-year-old sheep, or possibly that clones age differently from natural-born sheep. However, a few years later, Dolly’s cells were used to produce four more clones. Those clones were assessed at nine years and found to be aging normally and were as healthy as natural-born sheep of the same age. Michelle Kuepper of Research Gate talked to the study’s lead author Kevin Sinclair about Dolly, her clones, and the future of animal cloning.