Effects of dietary lipids on the hepatopancreas transcriptome of Chinese mitten crab (Eriocheir sinensis).

Banghong Wei,Zhigang Yang,Aqin Chen,Yongxu Cheng,Jianyi Wang,Qiuyan Shi,Linsheng Song

doi:10.1371/journal.pone.0182087

Abstract

Fish oil supplies worldwide have declined sharply over the years. To reduce the use of fish oil in aquaculture, many studies have explored the effects of fish oil substitutions on aquatic animals. To illustrate the effects of dietary lipids on Chinese mitten crab and to improve the use of vegetable oils in the diet of the crabs, 60 male juvenile Chinese mitten crabs were fed one of five diets for 116 days: fish oil (FO), soybean oil (SO), linseed oil (LO), FO + SO (1:1, FSO), and FO + LO (1:1, FLO). Changes in the crab hepatopancreas transcriptome were analyzed using RNA sequencing. There were a total 55,167 unigenes obtained from the transcriptome, of which the expression of 3030 was significantly altered in the FLO vs. FO groups, but the expression of only 412 unigenes was altered in the FSO vs. FO groups. The diets significantly altered the expression of many enzymes involved in lipid metabolism, such as pancreatic lipase, long-chain acyl-CoA synthetases, carnitine palmitoyltransferase I, acetyl-CoA carboxylase, fatty acid synthase, and fatty acyl Δ9-desaturase. The dietary lipids also affected the Toll-like receptor and Janus activated kinase-signal transducers and activators of transcription signaling pathways. Our results indicate that substituting fish oil with vegetable oils in the diet of Chinese mitten crabs might decrease the digestion and absorption of dietary lipids, fatty acids biosynthesis, and immunologic viral defense, and increase β-oxidation by altering the expression of the relevant genes. Our results lay the foundation for further understanding of lipid nutrition in Chinese mitten crab.

Highlights

As a source of energy, essential fatty acids, phospholipids, and some fat-soluble vitamins, lipids are indispensable in aquatic feed, for crustaceans [1, 2]
Most of our results suggested that substituting fish oil (FO) in the diet of E. sinensis is practicable, where vegetable oil could partially replace FO without affecting growth, but the fatty acid composition could be significantly altered [18,19,20]
Quality trimming, and adapter clipping, a total 320,973,688 reads were obtained from the hepatopancreas of E. sinensis fed FO, soybean oil (SO), linseed oil (LO), FSO (FO + SO), or FLO (FO + LO) diet (Table 3) and used for de novo assembly

Summary

Introduction

As a source of energy, essential fatty acids, phospholipids, and some fat-soluble vitamins, lipids are indispensable in aquatic feed, for crustaceans [1, 2]. Fish oil (FO) produced by wild fisheries has been the main lipid resource in aquatic feed because of the unidentified growth factors and high content of n-3 highly unsaturated fatty acids (HUFAs), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) [3]. For the sustainable development of the aquaculture industry, many studies have been conducted to identify other lipid resources to substitute FO in fish and crustacean diets [4,5,6,7]. Some vegetable oils, such as rapeseed, linseed, and soybean oil, are considered good alternative lipid resources that are cheap and obtained [8]. The effects of substituting FO in crustaceans warrant further study

Methods

Results

Discussion

Conclusion