Effects of amino acids on olfactory‐related receptors regulating appetite in silver pomfret

Silver pomfret (Pampus argenteus) performs a significant appetite for jellyfish, and amino acids are common components of the natural prey of fish, so we investigated the effect of aspartic acid, glycine and cysteine (high‐content amino acid in jellyfish) on olfactory‐related receptors regulating appetite in silver pomfret. The fish showed significant attractant responses to these amino acids in water, which were also observed to improve the ingestion rates of the fish. Next, we conducted transcriptomes of the olfactory epithelium (OE) and identified 34 olfactory‐related receptor genes were including olfactory receptors, trace amine‐associated receptors and vomeronasal receptors genes, and we examined these genes in the OE and appetite‐related genes (ghrelin and leptin in gut/stomach and neuropeptide Y, agouti‐related protein and proopiomelanocortin in brain) by qRT‐PCR. The olfactory‐related receptor genes significantly expressed in amino acid groups, and the expression level of appetite‐related genes was highest in aspartic acid group. Thus, olfactory‐related receptors induced by amino acids might regulate appetite in fish through the OE–brain–gut and stomach axis. Using these data, we identified some effective amino acid phagostimulants which could be supplied in silver pomfret diet, and the results improved our understanding of the mechanism of olfactory‐related receptors regulating appetite in fish.