Altered animals ‘resist disease’

Gene-edited pigs have been created which appear to be immune to a disease costing farmers more than £1billion a year in Europe alone.

The altered animals seem completely resistant to both major strains of the virus responsible for porcine reproductive and respiratory syndrome (PRRS).

PRRS causes severe breathing problems in young pigs and breeding failure in pregnant females.

It is one of the biggest health hazards faced by pig farmers.

Early tests showed cells from the genetically modified pigs were wholly immune to the virus, suggesting that the animals were protected.

Scientists at the University of Edinburgh’s Roslin Institute used the gene-editing technique CRISPR/Cas9 to disable a gene called CD163.

“It offers the chance to boost food security”

The gene is thought to play a key role in allowing the PRRS virus to target pig immune cells.

Next the researchers plan to see whether living pigs that have been gene edited are resistant to infection when exposed to the virus.

Lead scientist Professor Alan Archibald said: “Genome-editing offers opportunities to boost food security by reducing waste and losses from infectious diseases, as well as improving animal welfare by reducing the burden of disease.

“Our results take us closer to realising these benefits and specifically address the most important infectious disease problem for the pig industry worldwide.”

The findings are published in the journal Public Library Of Science Pathogens. The technique allows precise “cutting and pasting” of the genetic code.