Scientists from the laboratory which created Dolly the cloned sheep have now produced a disease-resistant piglet using a new technique which is simpler than cloning, paving way for genetically modified meat.
The piglet called "Pig 26" is the first animal to be created via "gene editing". It was born four months ago at Edinburgh's Roslin Institute, where Dolly the cloned sheep was created in 1996.
The new technique, which is faster and more efficient than existing methods, can alleviate major concerns of anti-GM campaigners because it does not involve the use of antibiotic-resistance genes, The Telegraph reported.
Scientists hope it could make genetic engineering of livestock more acceptable to the public and be key to the challenge of feeding 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 three billion "letters" that make up its genome.
It has a success rate of ten to 15 per cent, compared with less than one per cent 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 been artificially modified, researchers said.
"Unless you had an audit trail of how that animal was formed, you would have no way of knowing how that mutation happened. It could have happened naturally, or in this case been engineered by a DNA editor," Professor Bruce Whitelaw from Roslin 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," Whitelaw said.
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 and that international regulators were already considering how to classify it.
