British scientists are reported to have produced a disease-resistant piglet using a new technique which is simpler than cloning and could bring GM meat a step closer.
The method of creating genetically-modified animals addresses one of the principal objections of the anti-GM movement.
The “gene-editing” technique was developed at the Roslin Institute, the laboratory which created Dolly the sheep.
The technique is at least 10 times more efficient than existing GM technology, The Independent says here.
Crucially, it does not involve the use of antibiotic-resistance genes, which has been heavily criticised by opponents.
Researchers at the Roslin Institute in Edinburgh, where Dolly the cloned sheep was created in 1996, announced today that they have created the first GM pig with the technique as part of an ambitious project to produce disease-resistant animals by genetic engineering.
The male piglet, designated “pig 26” and born last August, has been genetically engineered with the smallest of DNA mutations – a single deletion of one out of the 3 billion chemical “letters” of its entire genome.
Scientists say the power of the new gene-editing technique is that it is extremely precise and improves the efficiency of creating GM animals by ten-fold or more.
It can be performed on fertilised eggs rather than ordinary tissue cells and does not need the antibiotic resistance “markers” and the elaborate cloning process that previous techniques relied on to produce GM animals.
Professor Bruce Whitelaw of the Roslin said the new technique produces GM animals with between 10 and 15 per cent efficiency compared with an efficiency of less than 1 per cent for the standard method of genetic engineering.
Similar techniques could be used to make other livestock such as cattle and sheep immune to a host of diseases, he said.
“We can do it without any marker or trace. Unless you do an audit trail there is no way that you would know how that mutation happened. It could have happened naturally, or by a DNA editor,” Professor Whitelaw said.
The new gene-editing technique does not leave any mark in the animal’s genome other than the desired mutation.
It merely mimics the natural evolutionary process, using a man-made genome editor.
“With the new technology we can work directly within the zygote [fertilised egg] with an efficiency of 10 to 15 per cent. In a litter of pigs at least one of the animals will have the edited event,” Professor Whitelaw said.
“We can get rid of antibiotic resistance and for some situations we can get rid of cloning or nuclear-transfer technology as well. I think cloning does have some baggage attached to it,” he said
“We as scientists are very excited about this because of very precise changes, and we see this as very powerful, but whether the public will see that as inherently different is another matter altogether,” he added.
Pig 26 is part of a research programme to create GM pigs that are resistant to infections such as African swine fever virus.
The Telegraph (here) says scientists hope the new technique could make genetic engineering of livestock more acceptable to the public and be key to the challenge of feeding the growing global population.
Its report describes “gene-editing” as 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.
The process is claimed to mimic 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.
Britain is reported to be highly unlikely to allow meat from genetically modified animals to enter the food chain in the forseeable future, but other countries such as the US and China could take a more relaxed approach.
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.