A Genome-Wide Association Study Reveals A Region Associated With Body Weight In Catfish

Growth is perhaps the most important economic trait. Fast growing fish not only increase production, but also have a better survival rate. Growth-related traits have been known to be quantitative traits in many species, but how growth is controlled in catfish was not known. Catfish is the major aquaculture species in the United States, accounting for over 60% of the US aquaculture production. In this study, we conducted a genome-wide association study (GWAS) for catfish body weight using the 250K SNP array with 556 backcross progenies generated from backcross of male F1 hybrid (female channel catfish x male blue catfish) with female channel catfish. A genomic region (approximately 1 Mb) on linkage group 5 was found to be significantly associated with body weight. Several genes in the associated region are known to be involved in muscle and bone development, some of which were reported to be associated with obesity in humans and pigs, suggesting that the functions of these genes may be evolutionarily conserved in controlling body weight. The results provide a basis for application of marker-assisted selection in catfish. Additional fine mapping or functional studies should allow identification of the causative gene for fast growth in catfish, and elucidation of molecular mechanisms of regulation of growth in fish.