Transcriptomic analysis reveals the hepatopancreas metabolic mechanisms of mud crab Scylla paramamosain fed diets with terrestrial animal fat sources replacing fish oil

Abstract

The transcriptome analysis following an 8-week feeding trial was employed to investigate the impacts of dietary terrestrial animal fats (TAFs includes lard oil (LO), beef tallow (BT) and poultry oil (PO)) replacing fish oil (FO) on the metabolic mechanism in hepatopancreas of mud crabs (Scylla paramamosain). The fatty acid (FA) transport, biosynthesis and lipid absorption and digestion were reduced through the regulation of PPAR pathway and the mRNA expressions of monoglyceride lipases (mgls), phosphatidate phosphatase-1 (pap1), acyl-sn-glycerol-3-phosphate acyltransferase delta (plcd), cAMP-dependent protein kinase catalytic (pkac), FA-binding protein 1 (fabp-1), FA transport protein 4 (fatp-4), short/branched chain specific acyl-CoA dehydrogenase (acdsb) and enoyl-CoA delta isomerase 2 (eci2), etc., after replacing FO with BT or LO. At the same time, dietary BT and LO regulated glycolysis, gluconeogenesis and insulin signals through increasing the genes of pyruvate dehydrogenase E1 (pdh), phosphoenolpyruvate carboxykinase (pepck) and phosphatidylinositol 3-kinase (pi3k) and regulated immunity status by down regulating the mRNA expressions of heat shock proteins 27 (hsp 27), cytochrome P450 (cyp 450), etc. Replacing FO with PO enhanced phospholipid storage, fat deposition, and inhibited glucose transport by up regulating pap1, mgls, lipin 1, lipinβ and down regulating glycosyl transferase (gt) and glucose transporter type 4 (glut4) expressions. The present study showed the signaling pathways and genes that were significantly regulated by TAFs replacing dietary FO, and revealed molecular mechanisms of TAFs in S. paramamosain. This would be conducive to the application of TAFs in aquatic feed.