Scientists create gene-edited pigs resistant to classical swine fever

UK – In a breakthrough that could transform global livestock production, scientists at the University of Edinburgh’s Roslin Institute have successfully created pigs resistant to classical swine fever (CSF), a highly contagious and often fatal viral disease that devastates pig farms worldwide.

The study, published in Trends in Biotechnology, marks the first time that gene editing has been used to confer full resistance to CSF in pigs. 

The research, conducted in collaboration with the Animal and Plant Health Agency (APHA), animal genetics company Genus, and the University of Lübeck in Germany, offers new hope for controlling one of the most persistent threats to pork production.

Classical swine fever, also known as hog cholera, causes fever, skin lesions, convulsions, diarrhoea, and often death within two weeks of infection. 

Though eradicated from the UK in 1966, sporadic outbreaks have continued, leading to the culling of tens of thousands of pigs. 

Globally, the disease remains endemic in parts of Asia, Latin America, and Europe, costing farmers billions through trade restrictions and vaccination costs.

To tackle this, researchers used CRISPR gene-editing technology to alter a single gene, DNAJC14, which produces a protein crucial for the virus to replicate inside pig cells. By changing just one amino acid in this protein, scientists effectively blocked the virus’s ability to reproduce.

Four of the gene-edited pigs were later exposed to CSF under secure conditions at APHA’s facility, alongside four unedited control pigs. 

The difference was striking. While the control animals developed fever and high viral loads, the gene-edited pigs remained completely healthy and showed no signs of infection.

“These animals were completely resistant to replication of the virus and remained happy and healthy throughout the study,” said Helen Crooke, deputy leader of mammalian virology at APHA. “Hopefully, this breakthrough can help bolster the resilience of the livestock sector to the disease.”

Implications for animal health and sustainability

The Roslin Institute, world-renowned for producing Dolly the sheep, has long been at the forefront of animal biotechnology. 

Its latest achievement builds on earlier work with Genus to produce pigs resistant to porcine reproductive and respiratory syndrome (PRRS), a disease that causes major reproductive and respiratory issues in herds. 

Those PRRS-resistant pigs have already been approved for sale in the United States and Brazil.

“This virus has a severe effect on animal welfare and productivity,” said Dr Christine Tait-Burkard, group leader at the Roslin Institute. “Vaccination takes a lot of coordination and monitoring, so developing animals that are naturally resistant is a game changer.”

The success of this research could also extend beyond pigs. The same DNAJC14 gene is used by pestiviruses that infect cattle and sheep, causing bovine viral diarrhoea and border disease, respectively. 

The Roslin team is now investigating whether the same genetic modification can confer resistance in these species, potentially protecting multiple branches of the livestock industry.

Toward a new era of precision breeding

The advance comes at a time when governments are reconsidering regulations around gene-edited livestock. 

The UK’s Precision Breeding Act has already paved the way for gene-edited crops, and similar discussions are ongoing for farm animals. Countries such as the US, Japan, and Brazil have approved gene-edited livestock, reflecting a growing acceptance of precision breeding as a safe and sustainable solution.

Dr Simon Lillico, research scientist at the Roslin Institute and co-author of the study, underscored the ethical dimension of this work. 

“In my mind, there is a moral imperative that if we can make animals that are disease resistant, then we probably should do,” he said.

As the world faces growing challenges in food security, animal welfare, and climate resilience, the creation of disease-resistant pigs could mark a pivotal step toward a more sustainable livestock future, one where science, ethics, and agriculture converge for global benefit.

The study was funded by the Biotechnology and Biological Sciences Research Council and supported by the Large Animal Research and Imaging Facility at the University of Edinburgh.

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