Dolly the sheep was the first animal to be cloned from an adult cell, and like many firsts, she came to stand in for all of her kind.
So when scientists suspected she had short telomeres—stretches of DNA that normally shorten with age—people wondered if it was because she was cloned from an adult cell. When she started to limp at age five, headlines said that her arthritis “dents faith in cloning.” And when she died at age six—as the result of a common lung virus that also killed other sheep in her barn—her short life again became a parable about cloning. A certain narrative took hold.
Then last year, Kevin Sinclair, a developmental biologist at the University of Nottingham, published a paper about several clones including Dolly’s four “sisters,” who were created from the same cell line as Dolly and lived to the old age of eight (about 70 in human years). They were quite healthy for their age. So of course, he kept getting questions, like if these animals are so healthy, then why was Dolly so unhealthy? It was Dolly that everyone cared about.
Sinclair would point out that Dolly was not so unhealthy. But the questions inspired his team to go looking for Dolly’s health records from the early 2000s. The records, however, were lost. “Everything has moved on. People had moved away, and people are doing other things,” says Sinclair. But after her death in 2003, Dolly’s bones were turned over to the National Museum of Scotland. Sinclair’s team got permission to study them—along with the bones of Megan and Morag, two sheep cloned from non-adult cells who were prototypes for Dolly, and Dolly’s naturally conceived daughter Bonnie.