LCFA Uptake and FAT/CD36: molecular cloning, tissue expression and mRNA expression responses to dietary oil sources in grass carp ( Ctenopharyngodon idellus )

摘要

ABSTRACT The fatty acid translocase (FAT/CD36) plays an important role in trans-membrane uptake of long-chain fatty acids (LCFA) and has been identified and described in many organisms, while little is known about this gene in freshwater fish, and especially in the grass carp ( Ctenopharyngodon idellus ). In this study, the uptake of LCFA in hepatocytes of C.????idellus was firstly determined and then FAT/CD36 gene was cloned; then the gene was sequenced and mRNA levels from different tissues and the effect of dietary oils on its expression were determined. Present data showed that trans-membrane absorption of LCFA was related to the type and concentration of fatty acids (FAs) and it could be inhibited by specific membrane uptake inhibitors. The FAT/CD36 isolated from grass carp contained 1422?￠????bp and the open reading frame was predicted to have 1403?￠????bp (GenBank access number: KU361231.1). FAT/CD36 was highly expressed in the brain and its lowest expression was in the gills. FAT/CD36 expression in white muscle was up-regulated when fish were fed with groundnut oil, whereas it was down-regulated in fish fed fish and linseed oils, respectively. These results indicated n-3 PUFA might inhibit the FAT/CD36 mRNA expression and therefore the oxidation of FAs. Abbreviations: Docosahexaenoic acid: DHA; Fatty acid: FA; Fatty acid translocase: FAT/CD36; Fish oil: FO; eicosapentaenoic acid: EPA; Groundnut oil: GO; Linseed oil: LO; Peroxisome proliferator-activated nuclear receptor: PPARs; Polyunsaturated fatty acid: PUFA; Unsaturated long-chain fatty acids: LCFA; Olive oil: OO