Title Molecular and cellular mechanisms of body lipid accumulation in fish
Authers Hiromi OKU
Keywords lipid metabolism, lipid accumulation, gene, adipocyte, cell culture
Citation Bull. Fish. Res. Agen. No.26, 63-68, 2008
Lipid is a main component of fish body, which affects flesh quality of cultured fish. In lipid accumulation process in fish body, the activation of various adipogenic genes and the enlargement of lipid storing tissues are postulated to be involved. In this study, we investigated the molecular and cellular aspects of body lipid accumulation process in red sea bream Pagrus major . Firstly, to investigate molecular mechanism of lipid accumulation in fish, various adipogenic genes including lipoprotein lipase (LPL1, LPL2), fatty acid synthetase (FAS) and fatty acid desaturase (d6DES, SCDa, SCDb) were characterized in red sea bream. The expression of identified adipogenic genes were, different from those of mammals, detected in various tissues including adipose tissue, hepatopancreas and muscle in red sea bream, suggesting the mechanism of body lipid deposition in fish contains different features from that in mammals. Subsequently, to investigate the cellular aspects of lipid accumulation in fish, the differentiation process of adipocyte, a main site of lipid storage, was analyzed in vitro by using primary culture system. In cultured red sea bream adipocytes, the differentiation was enhanced by insulin and the adipogenic gene expression including LPL, FAS, d6DES were activated in differentiation-dependent manner. Furthermore, their expression could be modified by Br-palmitate, a non-metabolic fatty acid. These results provide information on the molecular and cellular mechanisms of lipid accumulation process in fish body.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull26/oku.pdf