At the third virtual meeting of the EDIGEN initiative, aquaculture experts from the UK and the U.S. outlined promising developments in gene editing aimed at enhancing disease resistance and sustainability in farmed fish. The event, hosted by the University of Chile’s Faculty of Veterinary and Animal Sciences, featured presentations from Dr. Sarah Salisbury (University of Exeter) and Dr. Rex Dunham (Auburn University), both leading researchers in aquaculture genetics.
Targeting Sea Lice Through Cellular Insights
Dr. Salisbury presented groundbreaking research using single-cell RNA sequencing to identify genetic traits linked to sea lice resistance in coho salmon (Oncorhynchus kisutch). Her team discovered that coho salmon resist sea lice through skin thickening (epithelial hyperplasia) driven by specialized keratinocytes – traits absent in Atlantic salmon. This cellular defense response is complemented by strong expression of inflammation-related genes, such as GLPR2 and EGFRA.
Pink salmon, in contrast, activate immune defenses without visible tissue changes, while chum and Atlantic salmon show delayed or compromised responses. “Resistant species use the same cell types but regulate them differently,” Salisbury explained, suggesting gene editing could replicate these defense patterns in Atlantic salmon without introducing new cellular structures.
Precision Tools for Enhanced Aquaculture
Dr. Dunham, with decades of experience improving species such as catfish and tilapia, shared insights into using gene editing for growth, disease resistance, and nutritional quality. Techniques like disabling the myostatin gene have yielded fish that grow up to 70% faster and show improved omega-3 content.
He emphasized successful commercial applications, including gene-edited fish now on the market in Japan and Brazil. Dunham also highlighted the insertion of antimicrobial genes that quadruple disease resistance in catfish and stressed the importance of public education and regulatory clarity to support responsible innovation.
Regulatory and Biosecurity Considerations
While gene-edited animals are not currently approved for commercial use in Europe, Dr. José Manuel Yáñez of the University of Chile noted that the pace of development suggests regulatory shifts may be on the horizon. “Once the technology is activated, there’s no going back,” Yáñez said.
Dunham also underscored advances in genetic containment, including the development of sterile fish through targeted edits to the reproductive axis. These methods offer a secure alternative to physical barriers and support environmental biosecurity.
The Road Ahead: Integrated Genetic Strategies
Both speakers agreed that the future of aquaculture lies in combining traditional breeding, hybridization, and modern biotechnologies. “The best fish in aquaculture will result from intelligently integrated genetic programs,” Dunham concluded.