Gene-Edited Pigs Developed to Combat Classical Swine Fever

blockchain Researchers at Edinburgh's Roslin Institute have achieved a significant milestone in animal genetics by developing pigs that are resistant to the deadly classical swine fever (CSF). This viral disease is known for its high contagion rates and often fatal consequences for pigs. Although the UK successfully eradicated CSF in 1966, the disease has re-emerged through various outbreaks and remains a substantial threat to global pig farming.

Helen Crooke, deputy leader of mammalian virology at the Animal and Plant Health Agency (APHA), highlighted the devastating effects of CSF on livestock and farmers. “Classical swine fever is a devastating disease for livestock and farmers as we saw with the outbreak in the UK, 25 years ago,” she stated, expressing hope that this breakthrough could enhance the resilience of the livestock sector against such diseases.

Known alternatively as hog cholera or pig plague, CSF induces severe symptoms including fever, skin lesions, convulsions, and diarrhoea, often leading to death within just 15 days. Since the 1960s, the UK has faced periodic outbreaks, resulting in the culling of approximately 75,000 pigs. In countries where CSF is endemic, such as China, Russia, and Brazil, controlling the disease often involves expensive and labor-intensive vaccination programs along with international trade restrictions.

Dr. Christine Tait-Burkard, a group leader at the Roslin Institute, noted the significant impact of CSF on both animal welfare and agricultural productivity. The recent study, which is pioneering in demonstrating resistance through gene editing, focused on a specific gene responsible for the production of a protein called DNAJC14. This protein is vital for the replication of pestiviruses, the family of viruses that includes CSF.

Gene-Edited Pigs Developed to Combat Classical Swine Fever Previous research in cell cultures had indicated that modifying a few letters in the DNA sequence could thwart viral replication. Building on this knowledge, the scientists at Roslin engineered a line of pigs with identical genetic modifications. To test their resilience, four of these gene-edited pigs were exposed to CSF, alongside four control pigs, at a secure facility managed by APHA.

A week post-inoculation, the control pigs exhibited symptoms of the disease and had elevated levels of the virus in their bloodstream. In stark contrast, the gene-edited pigs remained entirely healthy, showing no signs of infection whatsoever. The researchers monitored several generations of these gene-edited pigs and found no adverse effects on their health or fertility.

The gene implicated in CSF resistance also plays a role in the replication of pestiviruses affecting cattle and sheep. Though these diseases are less severe than CSF, they still circulate within the UK. Consequently, the research team is currently exploring whether similar genetic modifications could confer resistance to these other species.

This advancement comes at a time when many nations are loosening regulations surrounding gene editing in agriculture. The UK’s Precision Breeding Act is paving the way for the use of gene-edited crops, while countries such as the United States, Japan, and Brazil have already approved gene-edited livestock.

Previously, based on research conducted at Roslin, the company Genus, located in Basingstoke, successfully produced pigs resistant to the virus responsible for porcine reproductive and respiratory syndrome. This ongoing research exemplifies the potential of gene editing in enhancing the resilience and welfare of livestock.

The creation of gene-edited pigs resistant to classical swine fever represents a significant breakthrough in the field of genetics and animal health. As the global agricultural landscape evolves, such innovations hold the promise of improving livestock welfare and safeguarding the livelihoods of farmers worldwide. The implications of this research could not only protect pigs but also serve as a foundation for further advancements in animal health, potentially benefiting various livestock species in the future.