For the scientists who created Dolly, the immediate legacy of their achievement is the continued existence of their research center.
Dolly the sheep, the most renowned sheep in human history, was the first mammal ever cloned from an adult cell. It required 276 attempts and immense effort to create her, making Dolly a groundbreaking scientific achievement that gained worldwide recognition in newspapers and magazines.
Dolly was born in July 1996 to a surrogate ewe and lived most of her life at the Roselin Institute in Scotland. Although her body was extensively studied, she lived a largely normal life for a sheep. Dolly was even allowed to mate with a ram, giving birth to six lambs: Bonnie, Sally, Rosie, Lucy, Darcie, and Cotton.
However, Dolly’s body had many health problems and she did not live to the age of 12 like normal sheep. Dolly’s additional clones, created from “the same cell line,” later proved much more successful, proving once and for all that cloning could produce normal, healthy animals, according to The Washington Post.
In the 1950s, biologist John Gurdon of the University of Oxford in England discovered how to clone Xenopus laevis. Since then, scientists have made similar attempts to recreate one creature that is genetically identical to another. Researchers tried everything from frogs to toads to fish, but this proved impossible, if not impossible, for large mammals at the time. (Image: Grunge).
Dolly the Sheep’s Short Life
Dolly died within a few short years of her birth – although her body was donated to the National Museum of Scotland for display. Even if you can’t make it to Scotland, you can still view a 3D digital model of Dolly on the museum’s website.
Dolly’s life, as previously noted, was tragically shortened due to health complications. In 2000, she was diagnosed with JSRV, a disease that leads to lung cancer in sheep. By the age of five, she had developed severe osteoarthritis of an unknown origin. Although her arthritis could be managed, the tumors in her lungs proved untreatable. On Valentine’s Day in 2003, at the age of six, Dolly was humanely euthanized.
At the time, many believed that Dolly may have had abnormally short telomeres for her age, caused by the cloning process. Telomeres act like caps on the ends of chromosomes and are linked to aging because they protect DNA. They shorten every time a cell divides, so having short telomeres is not a good thing and would make Dolly look older than she really is.
On July 5, 1996, a lamb was born that would change the entire biotechnology industry, giving scientists a new way to save endangered species and transforming the field of medicine in ways that were unimaginable at the time. This is no ordinary sheep, it was cloned using cells taken from the mammary gland of another sheep as part of an experiment carried out by the Roslin Institute in Midlothian, Scotland. The ewe was later named Dolly, after singer Dolly Parton. (Image: Grunge).
A clone of a clone
After the creation of Dolly, 13 additional sheep clones were produced. Among them, Denise, Dianna, Daisy, and Debbie were identical to Dolly, originating from the same mammary gland cells. However, unlike Dolly, these four clones have mostly lived outside the laboratory environment, as there were concerns that keeping them in the lab might elevate their risk of disease.
The new sheep appear to be much healthier than Dolly, leading some researchers to suggest that the cloning process does not accelerate the aging process as much as it did before. On the other hand, according to The New York Times in 2016, some of the 13 clones also developed arthritis, with Debbie being the most severe, but even that level of disease was not unusual. Other tests showed that the clones were relatively healthy, with normal blood pressure and insulin resistance.
It was later reported that the four clones of Dolly had all reached the age of 9, a respectable age for sheep. According to NPR, it was decided that when the clones reached 10 years old, they would be euthanized for a postmortem study of the entire flock.
Essentially, it is possible to reprogram all the DNA in the nucleus of an adult cell, causing it to start out as an embryonic cell and develop into a new animal. After unexpectedly creating an embryo, scientists at the Roslin Institute transferred it into the body of a third sheep, which eventually gave birth to Dolly. News of the successful cloning of a sheep was not announced until February 22, 1997, causing surprise and confusion to the public and many international media outlets. (Photo: Grunge).
