Abstract

The fisheries sector is a leading player in ensuring food security and contributes to global nutrition. The genome editing technique can enhance aquaculture to meet ever-growing demands and improve fish production’s efficiency and sustainability. Older tools, including meganucleases, zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), were used for genetic improvement for decades. CRISPR/Cas9 technology is applied in both diagnosis and therapeutics. The CRISPR/Cas system is popularly known for providing adaptive immunity in bacteria and archaea, is an effective tool for editing genes, and relies on two components: guide RNA (gRNA) and CRISPR-associated protein 9 (Cas-9). The editing mechanism involves three primary steps: recognition, cleavage, and repair. In 2020, Emmanuelle Charpentier and Jennifer Doudna became the first women to be awarded the Nobel Prize for discovering the CRISPR/Cas9 system. CRISPR has broad applications in areas like agriculture, biotechnology and medicine. In agriculture, it can help design new grains with higher nutritional value. In the medical field, it can be used for the detection of HIV and cancers and in gene therapy for sickle cell disease, Duchenne muscular dystrophy and cystic fibrosis. This technology has been utilised in fisheries to develop faster-growing strains of red sea bream, tiger puffer fishes and FLT-01 Nile tilapia. Disease-resistant strains were developed through CRISPR editing in grass carp and farmed rohu. Additionally, this tool has enhanced fish colouration by editing pigment-related genes, as in Nile tilapia, and optimised reproductive traits like fecundity and sex ratios. It prevented the inbreeding and trait reversal issues, with notable successes in sterile Atlantic salmon and all-female common carp populations. This article provides insight into the history of the discovery of CRISPR/ Cas9 technology and focuses on present status and future prospects in fisheries.