Comparative transcriptomics reveals domestication-associated features of Atlantic salmon lipid metabolism

Domestication of animals imposes strong targeted selection for desired traits but can also result in unintended selection due to new domestic environments. Atlantic salmon was domesticated in the 1970s and has subsequently been selected for faster growth in systematic breeding programmes. More recently, salmon aquaculture has replaced fish oils (FO) with vegetable oils (VO) in feed, radically changing the levels of essential long-chain polyunsaturated fatty acids (LC-PUFA). Our aim was to study the impact of domestication on metabolism and explore the hypothesis that the shift to VO-diets has unintentionally selected for a domestication-specific lipid metabolism. We conducted a 96-day feeding trial of domesticated and wild salmon fed diets based on FO, VO or phospholipids (PL), and compared transcriptomes and fatty acids in tissues involved in lipid absorption (pyloric caeca) and lipid turnover and synthesis (liver). Domesticated salmon had faster growth and higher gene expression in gl...