Adam Henson recounts the story of Dolly the Sheep, a 1990s cloned superstar of science
We’ve all seen buildings that have one of those commemorative blue plaques on the wall. It’s hard not to rush over to find out which famous writer, film star or artist once “lived here”.
But in Edinburgh the Roslin Institute have put up a blue plaque to a renowned character who didn’t publish, act in or paint anything – Dolly the Sheep.
Who was Dolly the Sheep?
For a short time Dolly was the superstar of science and her birth, in July 1996, changed the way we think about biology; she was the first mammal to be cloned from an adult cell.
It was a major scientific breakthrough and it led directly to modern stem cell therapies, designed to treat and prevent disease or medical conditions. There’s no denying that this was big news. Although Dolly’s story began, like so many scientific discoveries, in a humble test-tube.
When was Dolly the Sheep cloned?
In 1996 scientists at the Institute inserted DNA from a single udder cell of a Finn-Dorset ewe into an egg and implanted it in a surrogate mother. That meant that Dolly was an exact genetic ‘copy’ of the animal from which the single cell was taken and totally unrelated to the surrogate ewe.
This was the long-awaited breakthrough because up until that time, mammal clones had only been produced from the DNA of embryos, not adult cells. In fact, just the year before, the Edinburgh team had produced two identical sheep that were cloned from an original embryo. But Dolly was something altogether different.
When the world learned the news, seven months later, it led to high-profile arguments about the legal and ethical implications. Animal rights activists were angered by the development and religious groups voiced their concern.
If anyone thought that Dolly would be followed by widespread flocks and herds of cloned animals in the UK, or even a generation of human clones, then their predictions fell short. There’s been no real-life Jurassic Park. At the time, the man who led the team at Roslin, Dr Ian Wilmut, insisted that the idea of human cloning was “repugnant and illegal”.
Since then other mammals have been cloned with varying degrees of success, including cattle, horses, pigs and goats.
There’s particular interest in whether the technology could help endangered species in the future and it’s an area that organisations such as the Rare Breeds Survival Trust watch with curiosity. However, Dolly’s overriding impact is in stem-cell research – generating new tissue from a patient’s own cells and different ways to produce medicines.
When did Dolly the Sheep die?
So what became of the ewe who, for a brief time, became the world’s most famous sheep? Well, after breeding with a Welsh Mountain ram, she gave birth to a total of six lambs. But eventually poor old Dolly developed lung disease and arthritis and, in 2003, she was put down.
I don’t know if there are such things as blue plaque-spotters with tick-lists, but if there are, then they must rate Dolly’s commemorative plaque at Roslin as unique – instead of the usual “lived here”; her inscription reads “created at this institute”.
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