Why Scientists Kept the Birth of Dolly, the World’s First Cloned Mammal, a Secret for Seven Months

For seven months, Dolly’s birth was kept secret. That’s because unlike most lambs, her life started in a test tube. Her birth announcement on February 22, 1997, was not only a belated way to celebrate her arrival but also a confirmation that she had made history as the world’s first successfully cloned mammal.

Scientists at the Roslin Institute, an animal sciences research facility in Midlothian, Scotland, set out to prove that cloning a mammal was possible. They started with a single cell from a 6-year-old sheep’s mammary gland. That udder cell was inserted into an empty egg cell from another sheep, and over six days, a team at the Roslin Institute carefully studied it in a test tube, looking for signs of normal development. Early development was promising, and scientists transferred the embryo to Allie, Dolly’s surrogate mother. In total, three ewes contributed to Dolly’s creation.

It took 276 attempts to create a successful clone, but Dolly the cloned Finn-Dorset sheep was finally born on July 5, 1996. Named after country music star Dolly Parton, the ewe proved that scientists could take a specialized adult cell and use it to create new life. The Roslin Institute initially shrouded Dolly’s birth in secrecy as staff rushed to finish a research paper detailing their accomplishments. That paper was ready in February, and members of the press were invited to meet the lamb.

Dolly’s birth brought intrigue, excitement and controversy, sparking a still-ongoing debate about the ethics of cloning animals.

In fact, Dolly was not the first successfully cloned animal. Thirty-five years prior, in 1962, biologist John Gurdon had produced living tadpoles from the adult cells of a frog. But scientists agreed that there was something different about the lamb. Keith Campbell and Ian Wilmut, the biologists who created her, opted for a sheep because of their backgrounds in breeding the animals. They admitted that a lamb’s warm, soft nature made it a more appealing subject for cloning than a pig or cow.

How Dolly the Sheep was cloned

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The scientific community also rushed to understand the implications of the Roslin Institute’s success. Campbell and Wilmut hoped that cloning a sheep would pave the way for more advanced genetic research. They aspired to edit the genes of a sheep to tailor its milk to treat conditions like diabetes and cystic fibrosis.

Almost immediately, Dolly’s birth created a frenzy. Campbell and Wilmut were soon fielding hundreds of calls a day, and people were quick to speculate that their success with a warmblooded mammal would pave the way for human cloning. United States President Bill Clinton swiftly banned the use of federal funds to clone human beings, which led to legislation banning cloning human beings and regulating embryonic research. In 2005, after years of debate, the United Nations adopted its Declaration on Human Cloning, a nonbinding ban on the practice.

For Dolly, life largely carried on as normal. She lived with a flock of other sheep at the Roslin Institute and had six lambs with her mate, David. She gave birth to Bonnie, then twins Sally and Rosie, and finally triplets Lucy, Darcy and Cotton.

But Dolly’s life span was shorter than expected, and she died at just 6 years old in 2003. She had been diagnosed with arthritis in 2001 and lung cancer in 2003. Scientists euthanized her on February 14, 2003. Her death was used by opponents to argue that cloned mammals could not live full, healthy lives. But subsequent research concluded that Dolly and others like her aged normally.

Despite—or perhaps because of—the cloning controversy, Dolly’s legacy lives on. Scientists have continued to clone livestock, expanding to pigs, cows and horses. Today, scientists even clone beloved pets for pet owners willing to pay steep prices. In Midlothian, however, no traces of Dolly or her lineage remain. Her offspring have all since died, and the Roslin Institute’s programs have since been incorporated into the University of Edinburgh. Dolly’s taxidermied body holds a spot of great popularity at the National Museum of Scotland, where she has been displayed since 2003.

Sarah Holzmann | READ MORE

Sarah Holzmann is a freelance writer from the Arlington, Virginia, area.