Gene Editing Improves Alkaline Tolerance in Grass Carp

Researchers from Zhejiang Institute of Freshwater Fisheries and partners in China have identified a gene linked to alkaline stress sensitivity in grass carp. They used CRISPR-Cas9 gene editing technology to improve the fish's tolerance to high-alkaline environments. The study focused on the Cbr1 gene, which was found to play a negative role in the grass carp's adaptation to alkaline water conditions.

The team analyzed how the Cbr1 gene behaved under NaHCO₃-induced alkaline stress and found that its activity varied across tissues and over time. The researchers then used RNA interference to suppress the gene, which significantly increased the fish's survival rates under alkaline conditions. To further test its role, the scientists created gene-edited grass carp with Cbr1 deficiency and evaluated their responses to stress.

The edited fish showed improved antioxidant enzyme activities, altered serum biochemical parameters, and reduced histopathological damage. The findings suggest that disabling the Cbr1 gene could help develop more resilient grass carp strains for aquaculture in saline-alkaline waters. The findings of the study provide new insights into the molecular mechanisms involved in alkaline adaptation in freshwater fish.

For more information, read the abstract from Aquaculture.