The Roslin Institute, The University of Edinburgh, UK
You may know Dolly the sheep when she made history as the first animal cloned in 1996. Cloning prior to Dolly seemed like the stuff of science fiction books and movies to most of us. History was made when Dolly was born and cloning became a reality. When Dolly had to be euthanized prematurely at the age of six after suffering from a form of lung cancer, scientists speculated if it was because she was a clone. This may have all started at a conference where there was a mention of osteoarthritis in Dolly’s left knee which first showed up with she was five. Because sheep usually live until they are about 10 or 12, when Dolly died before the age of seven, scientists linked her early death and arthritis to cloning. New research shows that this isn’t actually true. Read on to learn more about Dolly and what caused her untimely passing.
Who Is Dolly The Sheep
In 1996, Dolly the sheep became the first animal ever cloned from adult somatic cells. Although cloning has always been a controversial subject, science has proven that it’s possible and advancements such as Dolly have are the proof. Dolly was cloned at the Roslin Institute in Midlothian, Scotland. The sheep was aptly named after Dolly Parton because scientists used a mammary cell in the cloning process. Her birth made scientific history then and is still being talked about today. A technique called somatic cell nuclear transfer was used to bring Dolly to life. This is the process in which a cell goes into a de-nucleated ovum. The two cells then fuse together and create an embryo.
It took 277 attempts, 29 early embryos implanted into 13 surrogate mothers, resulting in one full-term pregnancy to create Dolly. While many clones had been produced before Dolly, including mice, frogs, and cows, Dolly was the first from an adult cell. The others had previously been cloned using DNA from embryos. During her lifetime Dolly mated and produced offspring as sheep would naturally.
Cloning Wasn’t The Cause Of Death For Dolly
A sheep’s lifespan is typically 10-12 years. When Dolly passed away before the age of seven, scientists wondered if cloning was to blame. Two years before she passed she was diagnosed with early onset arthritis. While this is a common condition for sheep, suffering from arthritis at the age of five is early. When researches began to study four eight-year-old sheep from the same colonial line as Dolly, they began to suspect that her passing wasn’t the result of cloning or her arthritis.
Scientific Reports has published new research that shows the actual cause of Dolly’s death. To come to their findings researchers had to perform an X-ray of Dolly’s skeleton that was kept in Edinburgh at the National Museums Scotland. Researchers also examined Bonnie, Dolly’s daughter who was naturally conceived as well as Megan and Morag who were the first two animals to be cloned from different cells. The results proved that the osteoarthritis was more severe in the other sheep than in Dolly. No osteoarthritis was found in her carpal, shoulder or hook joints either. This proved that the original speculation about her osteoporosis and her premature death weren’t caused by her being a clone. Dolly’s actual cause of death was the lung cancer she was euthanized for in 2003. This form of lung cancer is common among sheep raised indoors.
Cloning Since Dolly
Since the birth of Dolly, many other sheep have been cloned using adult cells. Cats, horses, pigs, cattle, rabbits, and goats have all been successfully cloned this way. Because of the improved technology and the success cloning has had, cloning has now opened up more possibilities on the commercial market. Today, with a price-tag of around $100,000, you can clone a beloved family pet or elite livestock.