October 2025: Researchers have created pigs that are resistant to classical swine fever (CSF), a highly infectious and often fatal disease that poses a major threat to pig farming worldwide. Gene-edited pigs exposed to the virus remained healthy, while unedited animals showed typical signs of disease, a study found. Image credit: Simon Lillico The genetic change provided complete protection against infection, with no observable impact on the animals’ health or development, experts say.Researchers say the work demonstrates that precise gene editing can prevent infection by disrupting a pig protein the virus relies on to make copies of itself within the cells of the pig.The findings offer a promising route to bolstering disease resilience in livestock, they add. Targeted editing of genes Before producing gene-edited pigs, researchers worked with collaborators to study how a group of viruses including CSF, collectively known as pestiviruses, interact with pig cells. The team focused on a key pig protein, named DNAJC14, that had previously been shown to play an important role in the virus replication process when studied in cultured cells. In lab studies using these cells, altering the gene that produces DNAJC14 prevented the virus from reproducing. This suggested that making the same genetic change in live animals could produce livestock resistant to these viruses. Live trial Researchers made a precise change in a region of the DNAJC14 gene in pig embryos, preventing the virus from using the pig cells to produce all of its own viral proteins. The embryos were then implanted into surrogate mothers, and once the pigs reached adulthood, the research team exposed these gene-edited pigs to classical swine fever virus. Experts monitored the pigs’ health over several weeks, finding no signs of viral infection in the edited animals. By contrast, pigs which had not undergone gene-editing, and were exposed the virus, showed typical signs of infection. Our research highlights the growing potential of gene editing in livestock to improve animal health and support sustainable agriculture. While previous research had identified this protein’s role in cell cultures, translating that into living animals is a major step, and one that requires the infrastructure to breed, monitor, and safely test gene-edited livestock. Our Large Animal Research and Imaging Facility allows us to gene edit and assess a variety of livestock species, with colleagues at the Animal and Plant Health Agency providing expertise and biosecure facilities for this viral challenge. Dr Simon Lillico Core Scientist, the Roslin Institute Cross-species potential Classical swine fever is not currently found in the UK but continues to cause significant outbreaks in parts of Asia, Africa, Latin America and Europe, resulting in trade bans and serious financial losses for farmers. The pestivirus family includes diseases such as bovine viral diarrhoea virus in cattle and border disease virus in sheep. While there are vaccines for classical swine fever, control remains challenging due to virus persistence and transmission between species. The same genetic edit could theoretically be applied to other livestock species, offering broader protection against disease, the research team explains. This research was published in Trends in Biotechnology, in collaboration with animal genetics company Genus, and colleagues at the Animal and Plant Health Agency (APHA) and the University of Lubeck, Germany. The work was supported by a BBSRC National Bioscience Research Infrastructure grant and facilitated by the Large Animal Research and Imaging Facility at the University of Edinburgh. Read the full publication here Related links The Roslin InstituteDr Simon Lillico Publication date 22 Oct, 2025
