Expression of lipid, carbohydrate, and antioxidant metabolism-related genes in juveniles of cinnamon freshwater prawn Macrobrachium acanthurus, fed diets with different levels of protein, lipids, and carbohydrates

Abstract

A 60-day feeding trial was performed to determine the effects of diets with two levels of protein (35 and 40%) and three lipids to carbohydrate ratios (L:C ratios 2:1, 1:2, and 1:6) in the gene expression of lipid (acetyl-coA carboxylase, acc ; fatty acid synthetase, fas ; carnitine palmitoyl transferase-1, ctp1 ), carbohydrate (hexokinase, hk ; glucose-6-phosphatase, g6p ; phosphoenol pyruvate carboxylkinase, pepck ), and the antioxidant (catalase, cat ; glutathione peroxidase, gpx ; super oxide dismutase, sod ) metabolism in the juvenile Macrobrachium acanthurus . Each diet was fed to triplicate groups of ten organisms with an initial weight of 0.075 ± 0.015 g (mean ± SD) and after the 60 days, the thermal-unit growth coefficient (TGC) was calculated and samples of the hepatopancreas and gills were obtained, and then gene expression was determined. The TGC showed higher values in diets with 35% protein, but no significant differences were observed with respect of 40% protein treatments. acc and fas expressions were lower in the treatments 35% protein. In the 40% protein, the high expressions of fas and acc indicate an accumulation of lipids, while expression of pepck shows that glucogenic amino acids are used to synthetize glucose. Protein 35% improved the expression of antioxidant genes in the hepatopancreas but decreased in the gills. According with this, a level of 35% and L:C ratio of 1:2 seems to be an adequate combination of the macronutrients for the juvenile M. acanthurus .

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