Hepatopancreas transcriptomic reveal the metabolic mechanisms of terrestrial animal fat sources replacing dietary fish oil in green mud crab Scylla paramamosain

An 8 weeks nutritional trial and transcriptome analysis were used to investigate the impacts of dietary terrestrial animal fats includes poultry oil, beef tallow and lard oil replacing fish oil on the metabolic mechanism in hepatopancreas of mud crabs Scylla paramamosain. The results showed that a total of 753, 583 and 606 genes were significantly differently expressed in poultry oil vs fish oil, beef tallow vs fish oil and lard oil vs fish oil, respectively. After replacing fish oil with beef tallow or lard oil, fatty acid transport, biosynthesis and lipid absorption and digestion were reduced through the PPAR alpha pathway and the expression of monoglyceride lipases, phosphatidate phosphatase 1, acyl snglycerol 3 phosphate acyltransferase delta, cAMP dependent protein kinase catalytic, fatty acid transport protein 4, fatty acid binding protein 1, acyl CoA synthetase long chain family member, short branched chain specific acyl CoA dehydrogenase, enoyl CoA delta isomerase 2, aldehyde dehydrogenase family 3 member A2. At the same time, dietary beef tallow and lard oil would upregulate the genes of glycolysis, gluconeogenesis and insulin signals through pyruvate dehydrogenase E1, phosphoenolpyruvate carboxykinase and phosphatidylinositol 3 kinase and decrease immunity by downregulating heat shock proteins 27, cytochrome P450 etc. Beef tallow group enhanced protein synthesis through mTOR controlled pathways upregulating ribosomal protein S6, pi3k and down-regulating eukaryotic translation initiation factor 4E binding protein expressions. Replacing fish oil with poultury was enhanced phospholipid storge, fat deposition, and inhibiting glucose transport by upregulating phosphatidate phosphatase 1, monoglyceride lipases, lipin 1, lipin beta and downregulating glycosyl transferase and glucose transporter type 4 expressions. Furthermore, terrestrial animal fats groups can significantly downregulate the expression of genes such as transitional endoplasmic reticulum ATPase, malate dehydrogenase, and vehicle transport protein SFT2A. The present study revealed the molecular mechanisms of the hepatopancreas of Scylla paramamosain after replacing fish oil with terrestrial animal fats, increased basic knowledge of multiomics analysis of in a commercially important crustacean species, to lay a preliminary theoretical foundation for the development of terrestrial animal fats in the aquatic industry.