Catfish Inserted With Alligator Gene Via CRISPR Method to Protect Them Against Infection

Catfish is popular among Americans, as evident in catfish farms in the US that produced 307 million pounds (139 million kg) of it in 2021, as per The Fish Site. However, catfish aquaculture is an excellent breeding ground for diseases. According to Rex Dunham from Auburn University, roughly 40% of the catfish globally perish from when it hatched until being harvested due to illnesses.

In principle, genetically modifying fish with disease-fighting genes might cut waste and help restrict aquaculture's environmental effects. A group of scientists sought to achieve precisely that by adding an alligator gene into the catfish genomes. But could this new genetic modification really help?

Catfish Inserted With Alligator Gene Via CRISPR Method to Protect Them Against Infection Unsplash/Yosuke Ota

'Gatorfying' Catfish

Dunham and his colleagues from Auburn University found the alligator gene that codes for a protein called cathelicidin. The protein is said to be an antimicrobial, and it is considered to help protect alligators from infection in wounds sustained during their furious bouts. Dunham wondered if animals with the gene intentionally introduced into their genomes may be more disease resistant.

As per Big Think, the team has devised a novel approach to protect catfish against sickness by injecting the gene responsible for cathelicidin to prevent using antibiotics that have only led to the development of antibiotic-resistant diseases, which poses a huge threat to the world.

Prior research has demonstrated that cathelicidin, a peptide present in alligator blood, has antibacterial capabilities. Dunham and his colleagues also sought to guarantee that the resultant transgenic fish could not reproduce.

This is because genetically modified animals have the potential to disturb their surrounding ecosystems if they escape from farms and compete for food and habitat with their wild counterparts.

Genetically-Modified Catfish Have Higher Survival Rates

The team used the gene-editing technique CRISPR to transfer the alligator gene for cathelicidin into the region of the genome that codes for a crucial reproductive hormone. Dunham explains that the method is like killing two birds with one stone to protect the catfish and also prevent them from breeding.

The resultant fish appear to be more immune to pathogens, MIT News reported. When they put two distinct types of disease-causing bacteria in water tanks, they discovered that gene-edited fish were considerably more likely to survive than non-edited fish.

As Dunham said, the survival rate of the fish inserted with the gene for cathelicidin has a two- to five-fold greater chance of surviving a disease depending on the infection.

Researchers explained their findings further in the study, titled "Generation of Eco-friendly Channel Catfish, Ictalurus punctatus, Harboring Alligator Cathelicidin Gene With Robust Disease Resistance by Harnessing Different CRISPR/CAS9-Mediated Systems" published in the preprint server bioRxiv.

Farming disease-resistant fish will need fewer resources and result in less waste overall, researchers claim. But for now, their gene-editing method is complicated, and it would most likely need to be repeated for each cycle of fish spawning for the hybrid catfish widely employed in fish farming.