Sir Ian Wilmut, the scientist behind the famous cloning of Dolly the sheep, has died at the age of 79. He rose to fame in 1996, after becoming the first person to clone a mammal from an adult cell.
The pioneering embryologist always avoided the limelight and was surprised at the media frenzy surrounding his research, even though the biological significance of Dolly was immense.
Changing what scientists thought was possible, Dolly opened up groundbreaking new possibilities in medicine and biology, such as the development of personalised stem cells.
Before Dolly was born, scientists believed adult cells with a certain purpose, such as a liver cell or skin cell, held only the information to do that particular job.
When Wilmut discovered this wasn’t the case, it was a major boost to the field of regenerative medicine. It gave hope that bespoke new tissues or organs could be created for people to replace those lost to disease or accident.
In 2008, he was knighted by Queen Elizabeth II in the New Year Honours for his services to science and became one of history’s most famous biologists as a result of his find.
Early life
With an interest in animals and agriculture as a schoolboy, he had a weekend job as a farm hand. Born in the village of Hampton Lucy, in Warwickshire, in July 1944, he planned to join the Navy on leaving school. However, he was colour blind.
After undertaking part-time work on a farm while at the Boys' High School in Scarborough, he decided to study agriculture at Nottingham University.
In 1966, aged 24, Wilmut spent eight weeks working with the famous English biologist Christopher Polge in his Cambridge laboratory, the AI Centre.
A leading figure in the field of artificial insemination, Polge credited with developing the cryopreservation technique - a procedure to preserve sperm cells, in 1949.
Wilmut rejoined the laboratory in 1967, while studying for his Doctor of Philosophy degree at Cambridge University.
Dolly the sheep
On completing his degree, Wilmut joined the Roslin Institute in Midlothian, Scotland. The centre specialises in animal biosciences, with the aim of achieving sustainable agriculture, controlling diseases, and enhancing health.
He became the leader of a research group comprising experts from the Roslin Institute and PPL Therapeutics, who were conducting experiments into producing genetically modified livestock. They needed to learn about how cells change during their development - including whether a specialised cell could be used to create a new cloned animal.
The research team was made up of experts in their field with a wide range of skills including scientists, surgeons, vets, embryologists and farm staff. They cloned Dolly by combining an egg cell from a Scottish Blackface sheep and the nucleus of a mammary cell from a six-year-old Finn Dorset sheep. She was born to her surrogate mother, a Scottish Blackface sheep, on 5th July 1996.
There had been 276 unsuccessful attempts to carry out the procedure before Dolly, who was named after the country music legend Dolly Parton.
Why was Dolly so important?
When Dolly was born, she wasn’t the first cloned mammal. A small number of other sheep had been cloned in 1995 at the Roslin Institute including Morag and Megan, who were cloned from embryonic cells grown in the laboratory. However, Dolly was the first mammal cloned from an adult cell - proving that scientists could use specialised cells to create an identical copy of the animal they had come from.
When Dolly’s existence was announced on 22nd February 1997, there was a frenzy of media attention globally. Her birth changed the future of science and medicine. The Roslin team made the announcement to coincide with the publication of their scientific papers describing how Dolly had been produced.
The humble sheep captured the public’s imagination and became something of a celebrity. In the week following the announcement, the institute received around 3,000 phone calls from all over the world.
Professor Sir Peter Mathieson, Edinburgh University vice chancellor, described Wilmut as a “titan of the scientific world” who had “transformed scientific thinking” and “fuelled many advances in regenerative medicine.” However, the research also sparked a public debate about the potential dangers of cloning mammals, with some critics claiming it was morally wrong.
The possibility of human cloning led to a widespread international furore about the ethics and implications. President Bill Clinton introduced legislation to ban human cloning in the US. It was already illegal in Britain.
Wilmut didn’t enjoy being in the limelight, although scientists had to communicate more clearly with the public than ever before to clarify the medical benefits of the discovery in the field of regenerative medicine.
What happened to Dolly?
Dolly spent her entire life at the Roslin Institute, living a relatively normal life with other sheep, apart from the occasional media appearance.
Over the years, she had six lambs with David, a Welsh Mountain ram. They were all conceived and born normally. She gave birth to their first offspring, Bonnie, in April 1998 and her final lambs in September 2000.
In 2001, farm staff noticed Dolly was walking increasingly stiffly. The cause was unknown, but it was treated successfully with anti-inflammatory medication.
The average lifespan of a sheep is ten to 12 years, so she was quite young to have arthritis. It was suggested she may be biologically older than her actual age because her DNA came from an adult sheep. However, vets carried out regular health screenings on Dolly and didn’t find evidence of accelerated ageing.
Sadly, at the beginning of 2001, Dolly became infected by a virus, Jaagsiekte sheep retrovirus, which causes lung cancer. A number of sheep at the institute were infected during the same outbreak.
She continued to enjoy a normal quality of life until she developed a cough in February 2003. She was sent for a CT scan, which revealed lung tumours.
Sadly, she was too ill to recover and was humanely euthanised on 14th February 2003, at the age of six-and-a-half. Her body was donated to the National Museum of Scotland in Edinburgh, where she remains one of the most visited exhibits.
Later career
Wilmut was always modest about Dolly’s creation, crediting his colleague, the biologist Keith Campbell, with much of the discovery.
He continued to work in the field of regenerative medicine. Tragically, he passed away on 10th September 2023, aged 79, after losing his battle against Parkinson’s.
Many senior figures in the world of science paid tribute, including Prof Bruce Whitelaw, director of the Roslin Institute, who said science had “lost a household name".
Prof John Iredale, of Bristol University, who worked with Wilmut, described him as being "scientifically brilliant and shrewd”, yet possessing “warmth and humour.”
Today, his legacy continues all over the world, with scientists, biologists, biochemists and geneticists developing cures for debilitating diseases and medical conditions.
Safety and personal protection are paramount in these environments, with medical gloves used in a laboratory conforming to the highest standards. Laboratory gloves provide a shield against hazardous chemicals and materials to reduce the risk of exposure and accidents.
Health and safety measures are particularly important when working with animals to avoid the spread of infection, such as the outbreaks of foot and mouth disease in Europe in the 1950s and ‘60s that were traced to laboratories researching a cure.
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