For the scientists who created Dolly, the direct legacy of this achievement is the continuous existence of their research center.
The most famous sheep in human history, Dolly the sheep, was the first mammal in the world to be cloned from an adult somatic cell. It took 276 attempts and considerable effort to create Dolly, and this renowned sheep became a significant scientific milestone, appearing in newspapers and magazines around the globe.
Dolly was born in July 1996 thanks to a surrogate mother and lived most of her life at the Roslin Institute in Scotland. Although her body was thoroughly studied, she essentially led a normal life for a sheep. Dolly was even allowed to breed with a ram, giving birth to six lambs: Bonnie, Sally, Rosie, Lucy, Darcie, and Cotton.
However, Dolly’s body faced numerous health issues, and she was unable to live to the age of 12 like typical sheep. The additional cloned offspring of Dolly, formed from “the same cell line,” later proved to be much more successful, forever demonstrating that cloning can produce healthy, normal 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 an organism genetically identical to another. Researchers experimented with everything from frogs and toads to fish; however, this was not successfully achieved with large mammals, which was nearly impossible at the time. (Image: Grunge).
The Brief Existence of Dolly the Sheep
In just a few short years after her birth, Dolly passed away – although her body was donated to the National Museum of Scotland to become an exhibition piece. Even if you cannot visit Scotland, you can still view a 3D digital model of Dolly on the museum’s website.
As mentioned earlier, Dolly’s life was cut short due to health problems. In 2000, Dolly was found to be infected with the JSRV virus, a disease that causes lung cancer in sheep. By the age of 5, she suffered from severe, unexplained arthritis. While her arthritis was treatable, the tumors growing in her lungs were not. At the age of 6, Dolly was euthanized on Valentine’s Day in 2003.
At that time, many believed that Dolly might have had an unusually short telomere length for her age, caused by the cloning process. Telomeres act like caps at the ends of chromosomes and are related to aging as they protect DNA. They shorten each time a cell divides, so having short telomeres is not ideal, causing Dolly to age faster than her actual age.
On July 5, 1996, a female sheep was born. It subsequently changed the entire biotechnology industry, providing scientists with a new method to save endangered species and transforming the field of medicine in unimaginable ways at that time. This was truly not an ordinary sheep; it was cloned using cells taken from the mammary gland of another sheep as part of an experiment conducted by the Roslin Institute in Midlothian, Scotland. The female sheep was then named Dolly, after the singer Dolly Parton. (Image: Grunge).
Copies of the Clone
After creating Dolly, 13 other sheep clones were made. Four of these, Denise, Dianna, Daisy, and Debbie, were identical to Dolly, created from the same mammary cell. Unlike Dolly, these four new clones primarily lived outside of the lab environment due to concerns that keeping them in the lab could increase their susceptibility to disease.
The new sheep proved to be much healthier than Dolly, leading some researchers to believe that the cloning process did not accelerate aging as previously thought. 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 severely affected; however, even at her worst, this condition was not too unusual. Other tests showed that the cloned sheep were relatively healthy, with normal blood pressure and insulin resistance.
Later reports indicated that these four clones of Dolly had all reached the age of 9 – a respectable age for sheep. According to NPR, it was decided that when this flock of cloned sheep turned 10, they would be euthanized for a post-mortem study of the entire flock of clones.
Essentially, it is possible to reprogram all the DNA in the nucleus of a mature cell, making it begin to resemble an embryonic cell and develop into a new animal. After unexpectedly creating an embryo, scientists at the Roslin Institute implanted it into the body of a third sheep, which ultimately gave birth to Dolly. News of the successful cloning of the sheep was not announced until February 22, 1997, surprising and bewildering the public and many international media outlets. (Image: Grunge).
