Revolutionizing Resistance: The Role of CRISPR in Combating Sea Lice in Salmonids
Dr. Mark Fast, a professor of fish health and comparative immunology at the Atlantic Veterinary College (AVC) at the University of Prince Edward Island (UPEI), is a leading investigator in international initiatives aimed at addressing sea lice challenges in aquaculture, including CRISPResist, GenoLice, and LiceResist. A significant opportunity in this context is the exploration of differential resistance to sea lice among salmonids.
Collaborating with Onda, Dr. Fast and his team have identified mechanisms of resistance to sea lice in Pacific salmon within the only AQC3 lab in Atlantic Canada. Their research has demonstrated the successful application of CRISPR gene editing techniques in Coho salmon, which may offer insights into enhancing resistance to sea lice in Atlantic salmon.
The Story of Dr. Mark Fast
Dr. Fast’s research group, the Hoplite Research Lab, investigates how environmental factors influence host-pathogen relationships, particularly concerning cultured species like salmon. For over 20 years, the lab has focused on understanding the dynamics between sea lice and salmon, identifying and characterizing variations in susceptibility across salmonid species. Notably, Dr. Fast's team discovered that Coho and Pink salmon exhibit relative resistance to sea lice, identifying key genes and mechanisms responsible for this resistance.
The Challenge of Sea Lice in Aquaculture
Sea lice represent a significant challenge for the global salmon aquaculture industry, causing over a billion dollars in annual revenue losses. As the industry grapples with ineffective control measures and increasing resistance to traditional drug treatments, there is a pressing need to develop methods for conferring resistance to sea lice in Atlantic salmon, similar to the natural resistance observed in Pink and Coho salmon. Dr. Fast's team aims to explore the potential of CRISPR technology to manipulate genes in Coho salmon, providing a proof of concept for applying similar strategies in Atlantic salmon.
Why Dr. Fast Chose Onda
Dr. Fast selected Onda as a collaborator for several compelling reasons:
Unique Facilities: Onda possesses the only AQC3 facility in Atlantic Canada, enabling the study of Coho and Pink salmon outside their endemic ranges.
Established Collaboration: Dr. Fast had previously collaborated with Onda on characterizing the early phase response of Coho and Pink salmon to sea lice, appreciating Onda's ability to adapt infection models to meet research challenges.
Logistical Expertise: Onda's team proved to be an excellent resource for the successful shipping of fish gametes and juvenile fish from British Columbia.
How Onda Responded
Onda staff provided critical support in obtaining permits and managing the logistics for shipping Coho salmon eggs and milt to their facility. Despite challenges like late arrivals and multiple shipping events, Onda personnel remained flexible, often working late nights and weekends to facilitate the time-sensitive CRISPR editing process.
Onda’s in-house expertise offered essential equipment for micro-injections and consumables, along with guidance on timing and quantifying editing success. After successfully injecting over 6,000 fertilized eggs, Onda staff raised the embryos for nine months, providing ongoing assistance with sampling and updates on care, growth, and mortality rates. Their proactive involvement included sharing photographs of the development and contributing to study design based on their observations. During the infection trials, Onda’s support was invaluable for conducting exposures and sampling, often extending beyond normal working hours.
The Results
After three weeks of sampling infected fish that underwent CRISPR editing, the research team confirmed that over 10% of the edited fish exhibited a pigmentation knockout, resulting in a lack of pigmentation or albinism. Additionally, the edited fish demonstrated differential infection patterns over time compared to wild-type (unedited) fish, confirming the success of the CRISPR edits and the alteration of resistance to lice infection.
This marks a pioneering achievement, providing the first evidence that CRISPR technology can be effectively used to modify sea lice susceptibility and resistance in salmon, paving the way for developing more resistant salmon for the aquaculture industry.