Traditionally, fish farmers have improved their fish populations through selective breeding, choosing and breeding the best fish to pass on their favorable genes. However, this process is slow, especially if the heritability of the desired trait in the selected population is low.
Fortunately, genetic editing has come into play to accelerate genetic improvement at a dizzying pace. The incorporation of genetic editing can help identify specific genes related to commercially desirable traits and has the potential for genetic enhancements by fixing desired alleles.
A scientific review published by researchers from James Cook University delves into how scientists are using gene editing to expedite aquaculture by targeting specific genes linked to desirable traits such as reproduction and development, pigmentation, growth, and disease resistance.
Genetic Editing
There are two types of genetic modification technologies: gene transfer and gene editing. The former involves producing genetically modified fish by transferring genes using microinjection. Gene editing, on the other hand, is based on the insertion, deletion, or replacement of genes within the genome.
The study’s authors define genome editing as “the intentional alteration of an organism’s genome, often resulting in insertion, deletion, or replacement within any region of the genome.”
But here’s the real magic: genetic editing allows us to “quickly fix desirable genes” in the fish genome. This means genetic improvement occurs in generations, not decades, bringing us closer to a future where aquaculture species possess traits desired by both the farmer and the consumer.
The main tools employed in genetic editing and adapted for use in aquaculture include zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR).
Areas of Genetic Editing Application in Aquaculture
Reproduction and Development
Scientists report that several studies have used gene editing technologies to identify functional genes influencing neuroendocrine and endocrine systems that regulate reproduction.
Control over reproduction in aquaculture can provide numerous commercial benefits. For example, producing monosex populations for uniform sizes, rapid growth, and inducing sterility.
Additionally, genetic editing can increase fertility and egg production, ensuring that our fish farms have an ample supply of seeds.
Pigmentation
Pigmentation not only affects the coloration of aquatic organisms’ bodies but also the coloration of their flesh, with direct implications for consumer choice.
Genetic editing can modify pigmentation genes, producing fish with vibrant colors that meet consumer needs.
Growth
Growth rate is the most desired trait for aquaculturists because it allows for faster production. Scientists are using gene editing to adjust genes related to growth, leading to faster-growing fish.
Disease Resistance
Genetic editing can be used to build internal resilience against diseases, creating fish that are naturally more resistant to harmful pathogens, reducing reliance on antibiotics and keeping fish populations healthy.
Recent studies have focused on using gene editing to facilitate the development of increased disease resistance in breeding populations, as it facilitates the transfer of these traits to offspring.
Application in the Aquaculture Industry
The incorporation of genetic editing into the aquaculture industry has the potential to achieve genetic improvements through the rapid fixation of desired alleles. This process eliminates years of selective breeding to enhance desired commercial traits.
The study reports that several startups are incorporating genome editing into the aquaculture industry. However, it warns that several considerations must be taken into account before incorporation.
Key Challenges
According to the study, the incorporation of genome editing has the potential to change the aquaculture industry. However, there are some obstacles to overcome.
The use of genetic technologies within selective breeding programs depends on regulations and political, social, and economic aspects, especially in middle- and low-income countries. Some researchers have proposed protocols for evaluating the use of genome editing in aquaculture.
Conclusion
While gene editing in aquaculture is still in its research phase, its integration into improvement programs is just beginning. Scientists are actively developing methods to seamlessly integrate genetic edits into fishery production. But acceptance is key! The recent approval of genetically edited fish in certain markets marks a significant step forward in both regulatory and public acceptance.
In conclusion, genetic editing has the potential to revolutionize aquaculture by unlocking the secrets of desirable traits and accelerating genetic improvement. By combining this technology with other cutting-edge tools and prioritizing responsible development, we can create a revolution in the aquaculture industry, ensuring a prosperous future for aquaculturists.
Contact
Megan N. Moran
Centre for Sustainable Tropical Fisheries, College of Science and Engineering
James Cook University
Townsville, QLD, Australia.
Email: megan.moran@jcu.edu.au
Reference (open access)
Moran MN, Jones DB, Jensen SA, Marcoli R, Jerry DR. Optimising commercial traits through gene editing in aquaculture: Strategies for accelerating genetic improvement. Rev Aquac. 2023; 1-33. doi:10.1111/raq.12889
