Intensified production demands in commercial aquaculture elevate the risk for hypoxic events, primarily due to high-density farming, elevated temperatures, and increased nutrient loading. Hypoxia incidents lead to immediate and enduring negative impacts on fish health, growth rates, and overall facility productivity. Current methods to maintain healthy oxygen levels in hatcheries focus on hypoxia prevention rather than strategies to benefit fish during a hypoxic event.
Using knowledge associated with hypoxia response in other species we have initiated an in vivo CRSIPR gene editing screen to modify numerous target genes involved in hypoxia response in rainbow trout (RBT, Oncorhynchus mykiss). The gene editing targets include multi-site-targeting of genes involved with erythrocyte development to promote oxygen delivery. We are also making edits to improve vascular growth of the gills to increase surface area for oxygen uptake, and are editing signaling pathways involved in oxygen regulation and cardiovascular function. The phenotypic screening approach facilitates the characterization of complex genomic elements to better understand the underlying molecular mechanism at work during the physiological response to hypoxic events. Ultimately, this will enhance our insights into genetic traits that promote hypoxia tolerance, allowing us to strategically apply CRISPR technology to develop resilient founder fish for commercial aquaculture operations. The use of current prevention methods for low oxygen combined with the culture of hypoxia-tolerant fish could reduce the risk for negative impact from hypoxic events in commercial aquaculture.