ASF-Resistant Pigs Bred in UK

July 1, 2015 — 

The University of Edinburgh’s Roslin Institute is breeding pigs with a warthog gene to resist African swine fever (ASF). The newborn piglets, which are designed to be resistant to the disease African swine fever, could be among the first commercially viable GM animals to have been created in Britain, reports the Guardian. [Source: Pig Progress Jun 29, 2015]

The piglets are born on an isolated farm outside Edinburgh. Professor Bruce Whitelaw, head of developmental biology at the University of Edinburgh's Roslin Institute, which is responsible for the pigs, believes that the newborn piglets, which are designed to be resistant to the disease African swine fever, could be among the first commercially viable GM animals to have been created in Britain.

A trial, due to begin later this summer at either the Pirbright Institute or the Animal Health and Veterinary Laboratories Agency in Weybridge, will involve exposing 12 "edited" pigs and 12 normal animals to the virus and testing mortality and transmission rates in the two groups to assess whether the modified pigs fare better.

The gene-editing technique works by taking a fertilised egg and using molecular scissors to snip the pig genome at the target site – in this case an immune gene called RELA. The cell's natural repair process introduces a minor error, making the gene slightly less active than the normal version, producing a gentler immune response closer to that seen in warthogs. Scientists think this should confer resistance to African swine fever, because the disease causes the pig immune system to go into overdrive. "The immune system grossly overreacts to something that itself isn't that harmful," said Simon Lillico, a senior researcher at Roslin. "Warthogs still get infected, they just don't drop dead."

The scientists have also created pigs with the exact warthog version of the gene and the first three of these pigs are now entering a breeding programme ahead of a second trial due to begin next year.