Tissue distribution and nutritional regulation of peroxisomal fatty acid β‐oxidation genes: A preliminary study in two marine teleosts, turbot ( Scophthalmus maximus ) and tiger puffer ( Takifugu rubripes )

Abstract

Peroxisome plays an important role in the modulation of lipid catabolism in fish. The present study investigated the tissue distribution of five peroxisomal fatty acid β-oxidation genes, including vlcs, acox1, acox3, ehhadh and acaa1, in turbot and tiger puffer. Their expressions in response to different nutritional status (starvation and change in dietary lipid levels) were also studied. Both fish were fed diets with graded lipid levels (8%, 12% and 16%) for 9 weeks, followed by 1-month of starvation. The five genes were highly expressed in the liver, intestine and pyloric caecum of turbot, and tiger puffer intestine. High-lipid diets up-regulated the expression of vlcs and acox3 in tiger puffer liver, whereas did not affect the expression of all genes investigated in turbot. During the starvation, expression of acox1, acox3 and acaa1 in turbot liver was increased firstly from day 0 to day 10, and then was decreased, while expression of vlcs in muscle, and acaa1 in muscle and subcutaneous adipose tissue was linearly increased. In tiger puffer liver, the expression of peroxisomal β-oxidation genes increased linearly with starvation time, but the expression of acox3, ehhadh and acaa1 in the muscle firstly increased from day 0 to day 4–9, and thereafter decreased. In conclusion, the peroxisomal fatty acid β-oxidation genes were highly expressed in the liver and intestine of both turbot and tiger puffer, and starvation could stimulate and high dietary lipid levels have less impact on their expression.