Cloning and characterization of fatty acid transport proteins in Japanese seabassLateolabrax japonicus, and their gene expressions in response to dietary arachidonic acid

Abstract

In this study, putative cDNA of three fatty acid transport protein (FATP) isoforms, that is FATP1, FATP4 and FATP6, was cloned and characterized from the liver of Japanese seabass (Lateolabrax japonicus), and their expression in response to diets with different arachidonic acid (ARA) levels (0.05%, 0.22%, 0.37%, 0.60%, 1.38% and 2.32% of dry matter) was investigated through a feeding trial. Two subtypes of FATP1, that is FATP1a and FATP1b, were cloned for the first time. The Japanese seabass FATPs showed high identity to their orthologs in other fish species and mammals, but Japanese seabass FATP6 showed low identity to Japanese seabass FATP1 and FATP4. FATP1a gene was highly expressed in brain, liver and eye, whereas FATP1b had the highest gene expression in gill, followed by kidney, skin, eye, muscle and heart. FATP4 gene was primarily expressed in intestine, brain and eye. However, FATP6 had very low gene expression levels in almost all tissues. High levels of dietary ARA (0.60%~2.32%) enhanced the gene expressions of FATP1a and FATP4 in the intestine and the gene expression of FATP1a in the muscle, whereas the dietary ARA supplementation reduced the FATP1b mRNA expression in the liver. The gene expression of FATP1a, FATP4 and FATP6 in the liver, as well as the FATP4 gene expression in the muscle, was not significantly affected by dietary ARA levels. To our knowledge, this is the first study investigating the regulation of FATP gene expressions by dietary ARA.

Effect of dietary bile acids supplementation on growth performance, feed utilization, intestinal digestive enzyme activity and fatty acid transporters gene expression in juvenile leopard coral grouper (Plectropomus leopardus)

“…FXR, Farnesoid X receptor; LXR, liver X receptor; TGR5, G-protein-coupled bile acid receptor-1. (Kaitetzidou et al, 2015;Xu et al, 2017). In this study, the supplement of bile acids (0.3%) significantly increased fish intestine FABP2 gene expression.…”

Arachidonic acid matters

“…FATP are key proteins in cellular uptake and metabolism of long and very long-chain fatty acids, whereas FABP plays important roles in intracellular lipid uptake and overall lipid homeostasis. 202,203 In European sea bass, Torrecillas et al observed that with reduced dietary ARA levels (0.2%-1.4% d.w. or 1.0%-6.0% TFA), hepatic lipid (1) COX seems to prefer ARA as substrate.…”

“…In fact, varying and contrasting results were also observed regarding the effects of dietary ARA on gene expression of various subtypes of fatty acid transport proteins (FATP) and fatty acid‐binding proteins (FABP). FATP are key proteins in cellular uptake and metabolism of long and very long‐chain fatty acids, whereas FABP plays important roles in intracellular lipid uptake and overall lipid homeostasis 202,203 …”