A transcriptome analysis focusing on growth performance and lipid metabolism‐related genes of grass carp ( Ctenopharyngodon idella ) fed with tea polyphenols basal diets

Several studies have highlighted the effect of Tea polyphenol (TPs) on growth performance and the gene regulation associated with the metabolic pathway and of various species. However, there is less information about the effect of TPs on growth performance and the regulation of genes related to the metabolic pathway of Grass carp (Ctenopharyngodon idellus). Six diets with different TPs level (0, 250, 500, 1,000, 2,000 and 4,000 mg/kg) were formulated. Result found that TPs increased the feed conversion efficiency (FCE) at different levels, and the highest FCE and specific growth rate (SGR) (p < 0.05) were achieved by the 500 mg/kg in the TPs group. Additionally, transcriptome sequencing of control and TPs groups was performed, and numerous differentially expressed genes (DEGs) were determined in the metabolic pathway of grass carp. The differentially expressed genes were validated by the qRT-PCR technique. DEGs were associated with arachidonic acid metabolism, linoleic acid metabolism, alpha-linolenic acid metabolism, biosynthesis of unsaturated fatty acids, fatty acid biosynthesis and fatty acid degradation. Our findings could provide new insight into the effect of TPs on growth performance and the regulation of genes associated with the metabolic pathway of grass carp.