A decade after Dolly, what will the cloners create next?

But Time magazine called Wilmut "Dr Frankenstein". Dolly was described as "a wolf in sheep's clothing", by sceptics who feared she was a harbinger for an era of human cloning.

Ten years on, Dolly is peacefully at rest and on February 14, the anniversary of "Dolly Day", a party will be held at the National Museum of Scotland's science and technology gallery, where "sheep 6LL3" (as she was named) is on display with other iconic "inventions", such as a Nasa space capsule.

Wilmut and Campbell will be there to offer their perspective on how their "invention" has changed our world. "I remember, 10 years ago, all the hype at the time of the announcement was about human cloning," says Wilmut, head of Edinburgh University's £59m Centre for Regenerative Medicine. "Very quickly, all kinds of people were claiming they were going to do this, including the Raelians, but I don't think we took them seriously."

It is cloned animals which created the most sensational headlines. In Australia, scientists are attempting to resurrect an extinct species - the Tasmanian tiger or thylacine. In America, two cloned mules are winning the big prizes in races.

• CLONED FOOD
  Perhaps most controversially, cloned beef is legal for human consumption in the US. Does this mean we will soon be feasting on clone burgers? Not likely, says Campbell. "Cloning cattle is not about making the perfect beefburger," he says. "It's more geared towards creating livestock which are resistant to diseases. If we can reduce the incidence of disease in farm animals, they have a better quality of life, the farmer can reduce use of antibiotics and we're not producing a host of resistant bacteria."

Wilmut agrees. "If you introduced a bull of high genetic value as a way of lifting the quality of the herd, then the last thing you'd do is eat that bull. You'd want it to breed as much as possible. We might eat beef from the offspring of clones, but we won't be dining on clones themselves."

• THE ANIMAL LAB
  It is in medicine, not the media, where Dolly has had her greatest impact, according to Campbell and Wilmut. Using their technique - nuclear transfer - a whole farmyard of genetically modified animals has been created, to help manufacture medicines and organs for human transplant including hens whose eggs contain anti-cancer drugs.

"There's even a group in the US Midwest who have created cattle that produce human antibodies in their milk," says Wilmut. The animal is, in effect, a walking drug factory. But why is the useful? "In the human body, some cancers don't raise an immune response - that's why they survive," says Wilmut. "But if you put that cancer into this cow, raised human antibodies to the cancer and then put those back into the patient, you might be able to challenge the cancer that way."

Keeping these cows could help us respond to a bio-terror attack, says Campbell. "The cows can produce a lot of human antibodies to a disease quickly, to create stocks which would give governments a head start when combating germ warfare."

• TRANSPLANTS
  Pigs with human-like organs have been created in the US, with the aim of addressing shortages in suitable human organ donors. "Normally, any pig tissue put into a person will be destroyed within minutes by the immune system," says Wilmut. "But they've changed the pig cell surfaces to make the organ much less recognisable. This allowed it to survive much longer in lab simulations - the average was two or three months. That's a dramatic change - from being destroyed in minutes to two or three months - but it's still not long enough to succeed in a human."

• HEALING CELLS
  Ten years after Dolly, growing human organs inside animals remains a distant and unlikely prospect. Instead, most scientists have pinned their hopes on healing damaged hearts, livers and kidneys by using a patient's own stem cells to grow replacement tissue.

Finding stem cells in the human body is difficult "but Dolly made people think differently," says Wilmut. "We used to think that cell types were so complex and rigidly fixed, they couldn't be reversed. Once a stem cell differentiated into a particular adult cell type, that was it. We now know that's not the case. When we produced Dolly, those mechanisms were reversed. We took an adult sheep cell and turned it into an embryonic stem cell."

• A CURE FOR DIABETES?
  This gave birth to the idea of therapeutic cloning, which could potentially be used to cure almost any human disease. Diabetes, for example, could in theory be cured by taking a cell from a patient's blood and injecting the DNA into an empty human egg to create a cloned embryo, from which insulin-producing cells could be grown and then re-injected into the body.

"This has many advantages" says Campbell. "In a normal organ transplant operation, many cells will be rejected. It would be much better if people could have a perfect match, by being treated with their own cells. But whether that can be done or not, we don't yet know. And I doubt whether we're ever going to have enough human eggs donated."

• HYBRID EMBRYOS
  The problems are not only practical. Creating cloned embryos from human eggs remains controversial, even in the UK, the only country to have successfully achieved the feat. One alternative - using animal eggs instead of human eggs - has provoked a storm of controversy, as it would create a hybrid embryo, with a mixture of human (99%) DNA and cow (1%) DNA.

Wilmut is one of a handful of scientists who have applied for a licence to create hybrid embryos, from the Human Fertilisation and Embryology Authority.

"Cells from cloned embryos are very useful but I can't envisage a time when they'll be used for therapy, for all sorts of practical reasons," says Wilmut. "We don't know that the cells we produced would be normal, or if they would be OK to put into humans. We think the best thing that nuclear transfer can be used for is to study inherited genetic diseases."

• THE FUTURE
  To study motor neurone disease, for example, Wilmut plans to take a cell from a patient with the disease mutation and create an embryo genetically identical to the patient. From that, he would grow cells which could be used to model the disease and test new drug therapies on it.

"We don't even know yet whether we'll be allowed to use animal eggs. The Human Fertilisation and Embryology Authority ruling on that will be important. What this has stimulated people to do is to come up with other ways to create stem cells - without creating embryos".

Scientists in Japan have done just that - changing an adult differentiated cell back to a stem cell, without inserting human or animal eggs.

"That's not only because of the Dolly experiment. But the Dolly experiment did give some impetus to the approach," says Wilmut.

The technique is more difficult, but more promising than cloning as it would sidestep ethical objections. Wilmut's team are working on using adult cells in cornea transplants and repair damaged bone tissue.

Meanwhile, Campbell and his team at the University of Nottingham's division of animal physiology are working on cloning rats to provide models for human diseases.

"We are working towards benefiting people. But people don't always recognise that," says Campbell. "Modern technologies always raise questions and anxieties," adds Wilmut. "There were similar anxieties at the first IVF."

Does this mean we have nothing to fear from cloning? "It would be misleading to suggest we don't need regulation. Any move to ban reproductive human cloning universally would be very beneficial. There will be some states in the US where it is legal to clone a human," Wilmut says.

"But I'm more afraid that we'll miss out on opportunities than that technology will be misused. To me, that's a bigger risk."