Transcriptomic analysis reveals olfactory-related genes expression in large yellow croaker (Larimichthys crocea) regulated by taurine: May be a good phagostimulant for all-plant protein diets

Abstract

Taurine is usually included in fish feed as a nutritional supplement, and it can also improve feed performance. To assess the potential use of taurine as a feed attractant in plant protein-based diets, we examined four different concentrations of taurine to determine the optimal levels for attracting large yellow croaker (Larimichthys crocea). The fish displayed the most significant attractive responses to 3.5% taurine and showed good feed performance with an all-plant protein diet supplying 3.5% taurine. Next, deep sequencing of the olfactory epithelium was conducted to identify genes differentially expressed in the taurine group (Tau) versus controls.We found that 11,793 unigenes were differentially expressed: 10,795 were upregulated and 998 were down-regulated unigenes. We detected 77 olfactory receptor genes, including 37 up-regulated unigenes, and validated the expression dynamics of eight genes using quantitative reverse transcription-PCR (RT-qPCR). We utilized Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) to analyse the function of the differentially expressed genes, which were mainly involved in signaling and cell communication (GO) and olfactory transduction (KEGG). Cumulatively, our results indicate that taurine could be a good phagostimulant for plant protein-based diets for L. crocea. Furthermore, improved understanding via olfactory epithelium transcriptomic analysis would inform the development of an all-plant protein diet for L. crocea. K E Y W O R D S all-plant protein diets, Larimichthys crocea, olfactory-related genes, taurine, transcriptomic analysis for Zhejiang Marine High-Efficiency and

Transcriptome sequencing of olfactory-related genes in olfactory transduction of large yellow croaker (Larimichthy crocea) in response to bile salts

“…We believe that fishes have limited olfactory-related receptors, which leads to limited olfactory ability, explaining why they do not exhibit significantly more intense behaviour with increased levels of odours. This suggests that fishes may possess a maximum detection peak for concentrations of certain stimuli, and a similar phenomenon has been observed in other studies ( Zhao, 2007 ; Hu et al, 2017 ).…”

“…To date, three types of receptor genes have been identified in fishes, namely olfactory receptors (ORs) ( Freitag et al, 1998 ), vomeronasal receptors (VRs) ( Freitag et al, 1995 ), and trace amine-associated receptors (TAARs) ( Eisthen, 2004 ). Among them, OR genes play an essential role in many odor detecting activities ( Hu et al, 2017 ; Yabuki et al., 2016 ; Bird et al., 2018 ). ORs encoding G protein-coupled receptors expressed in ciliated sensory neurons were previously identified in Rattus norvegicus ( Buck & Axel, 1991 ).…”

Effects of Amino Acids on Olfactory-Related Receptors Regulating Appetite in Silver Pomfret

“…Amino acids can bind to olfactory-related receptors that activate the G protein to transfer the olfactory signal (Saberi and Seyed-allaei, 2016, Ronnett and Moon, 2002). In the present study, OR, VR, and TAAR, three olfactory receptor gene families in sh, were all observed to be differentially expressed, which was consistent with our previous study (Hu et al, 2017). We suggested that a single amino acid could stimulate the three receptors which may work synergistically for the production of olfactory signal.…”

“…Amino acids are common components of the natural prey of shes, and even in the presence of single amino acid, olfactory receptors of shes can bind it and trigger feeding behaviors (Hara, 2010, Franklyn et al, 2017. Therefore, amino acids are considered good phagostimulants when mixed with feed (Hu et al, 2017, Bell et al, 1996, and these phagostimulants can signi cantly affect the appetite of sh through their olfactory neural circuitry (Tandler et al, 1982, Koide et al, 2009. Odorant molecules released into the environment bind to olfactory-related receptors (Kaupp, 2010).…”

Transcriptomics in aquaculture: current status and applications

“…Hu et al . () analyzed the olfactory epithelial transcriptomics in large yellow croaker to identify the gene expression pattern regulated by taurine.…”