Lipoprotein lipase (LPL) is highly expressed and active in the ovary of European sea bass (Dicentrarchus labrax L.), during gonadal development

The oocytes of many fish species accumulate high amounts of neutral lipids as a caloric reserve for embryonic larval development. We propose that lipoprotein lipase (LPL, EC 3.1.1.34) plays an important role in the oocytes with fatty acids and we have cloned its cDNA from the ovary of sea bass, and the patterns of LPL activity and LPL mRNA expression in the ovary. The cDNA obtained was bp long with an open reading frame encoding 518 amino acids. The amino acid sequence has a high and shows similar structural features to LPL of other species. Northern blot analysis revealed LPL in adipose tissue and gonads only. LPL activity and LPL mRNA expression in the ovary was very in fish with a gonadosomatic index (GSI) above 5, coinciding with the appearance of a high number of lipid droplets in the ooplasm. The LPL mRNA expression was localised to the follicle cells surrounding the Our results suggest that LPL is likely to play an important role in the incorporation of neutral lipids into the oocytes, and that follicle cells, in addition to participating in steroidogenesis, also may be important in building up oocyte lipid reserves. (C) 2008 Elsevier Inc. All rights reserved.