Scientists produce disease-resistant piglet

The laboratory which created Dolly the sheep has produced a disease-resistant piglet using a new technique which is simpler than cloning and could bring genetically modified (GM) meat a step closer.

The piglet, known only as "Pig 26", was the first animal to be created via "gene editing" when it was born four months ago at Edinburgh's Roslin Institute.

The new technique, which is faster and more efficient than existing methods, avoids one of the major concerns of anti-genetic modification campaigners because it does not involve the use of antibiotic-resistance genes.

Scientists hope it could make genetic engineering of livestock more acceptable to the public and help feed the growing global population.

"Gene-editing" is a simple and precise process whereby researchers snipped the animal's DNA and inserted new genetic material, in effect changing a single one of the threebillion "letters" that make up its genome.

It has a success rate of 10% to 15%, compared with less than 1% for existing methods, and can be performed on a fertilised egg without the need for complicated cloning techniques.

The process mimics a natural genetic mutation so closely that it would be impossible to tell from examining the animal's DNA whether or not it had beenartificially modified, researchers said.

Professor Bruce Whitelaw said: "We can get rid of antibiotic resistance and for some situations we can get rid of cloning as well. I think cloning does have some baggage attached to it."

Pig 26 was engineered to have a gene making it immune to African swine fever, a virus which can kill European pigs within 24 hours of infection.

The gene was taken from wild African pigs, which are naturally immune to the virus, but which cannot breed with European species.

Whitelaw said similar techniques could be used to make other livestock, such as cattle and sheep, immune to a host of diseases.

He added that the new form of "clean" genetic engineering has attracted interest from a number of commercial companies.

The US Food and Drug Administration is already considering whether to declare a genetically modified Atlantic salmon, which is engineered to grow unusually quickly, fit for human consumption.