Disease reduction in aquaculture with genetic and genomic technology: current and future approaches

Abstract

Reduction in the occurrence and severity of disease in aquaculture would improve the productivity, profitability, efficiency and welfare of aquacultural fish. Genetic approaches that have been successfully implemented in aquaculture to enhance disease resistance and reduce disease incidence include classical selection, genetic marker‐assisted selection, intraspecific crossbreeding, interspecific hybridization and transgenesis. The rate and speed of improvement in disease resistance varies from one genetic enhancement programme to another. Genome editing with zinc finger nucleases (ZFNs), transcription activator‐like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPRs)‐CRISPR‐associated protein 9 (Cas9) opens avenues for targeted genome modifications. This technology can be applied in aquaculture to manipulate disease‐resistance genes by means of gene knock‐in, gene knockout and regulation of gene expression. The maximum rate of improvement can be achieved by combining different genetic enhancement programmes. Here, we present a review for the current and future prospect of disease reduction in aquaculture with genetic and genomic technologies.

Effects of Cecropin Transgenesis and Interspecific Hybridization on the Resistance to Ichthyophthirius multifiliis in Channel Catfish and Female Channel Catfish × Male Blue Catfish Hybrids

“…Enhancement of disease resistance would result in higher survival rates and lower losses due to diseases, which should lead to increased aquacultural productivity, profitability, and efficiency and enhanced welfare of fish (Dunham ). Disease resistance in aquaculture can be enhanced through selective breeding, crossbreeding, interspecific hybridization, and transgenesis (Dunham ; Elaswad and Dunham ).…”

Genome editing on finfish: Current status and implications for sustainability

“…Other possibilities were later presented by Gotesman et al 19 where genome editing and RNAi were pointed out as useful therapy tools for combating pathogens in aquaculture. A concomitant review by Elaswad and Dunham 18 described how different genetic and genomic tools for disease reduction in aquaculture could be achieved by the CRISPR/Cas system. They also highlight the possibility for knock‐in (KI) procedures and to the benefits by the combination of genome editing and selective breeding 18 …”

“…Here, we present findings from a systematic review on the current status of genome editing in aquacultured finfish species, hence extending previous reviews. 5,9,18,19,20,21,22 As published in the previous reviews, 5,9,22 there is still a high focus on reproductive traits, but this has recently been expanded to include genes related to other production traits such as disease resistance.…”

Genome editing and its applications in genetic improvement in aquaculture

“…Due to the rapid development of sequencing technologies and reductions in the costs of DNA sequencing and genotyping of many DNA markers, [5][6][7][8] QTL mapping and GWAS for important traits, including growth, reproduction and meat quality, have been conducted for over 40 aquaculture species. 5,6,9 DNA markers such as SNPs (Single nucleotide polymorphisms) and microsatellites are being used in marker-assisted selection (MAS) and genomic selection (GS) to accelerate genetic improvement.…”