Effects of dietary vitamin E on the growth performance, immunity and digestion of Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂ by physiology, pathology and RNA-seq

Abstract

Vitamin E (VE) is an essential nutrient for most animals. Investigating the requirement and effects of vitamin E for Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂ would be meaningful. In the study, a 12-week feeding trial was conducted via the juvenile fish (initial body weight: 20.48 ± 0.20 g), and the physiological and biochemical indexes detection, histology observation and transcriptome analysis were operated to reach our goals. The results showed that vitamin E deficiency would result in bad effects on the growth, immunity and digestion, and induced some injury for the tissues. The analyse of quadratic regression curve and broken-line regression curve for some representative parameters revealed the optimal dosage of dietary VE for the fish was at 130.12–156.52 mg/kg. Comparative transcriptomic analyses revealed that VE mainly regulated the inflammatory response related genes(IL-1β, Irak3, Irak4, Nfkbia), immune related genes (Cd40, Fos, Cxcl9, Ccl20, Cxcr, Tnfaip3, Akt, Calca), membrane stability genes (Fgf1, Mrl and Gadd45b) and metabolism related genes (Gck and Ins) to influence the liver function and for the foregut, the functional metabolism related genes were Try3, Prss2, Cel, Pla2g1b, Ins Socs3 and Sqle and the Socs3 maybe also an important function gene in maintaining a good status of the foregut. Our study provided a new insight of VE function on the fish, meanwhile, it enriched the bioinformatic data of this species, as well as contributed to the healthy culture of the fish.