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 and larval development. We propose that lipoprotein lipase (LPL, EC 3.1.1.34) plays an important role in supplying the oocytes with fatty acids and we have cloned its cDNA from the ovary of sea bass, and determined the patterns of LPL activity and LPL mRNA expression in the ovary. The cDNA obtained was 3051 bp long with an open reading frame encoding 518 amino acids. The amino acid sequence has a high similarity and shows similar structural features to LPL of other species. Northern blot analysis revealed LPL expression in adipose tissue and gonads only. LPL activity and LPL mRNA expression in the ovary was very high 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 oocyte. 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.
Departmento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas, 12595 Torre de la Sal, Castellón, Spain.
Antonio
A
José Ibáñez
Julia
J
Peinado-Onsurbe
Elisa
E
Sánchez
José Miguel
JM
Cerdá-Reverter
Francisco
F
Prat
D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass / Q000196:embryology* / Q000378:metabolism*; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004789:Enzyme Activation; D005060:Europe; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008071:Lipoprotein Lipase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010053:Ovary / Q000166:cytology / Q000196:embryology* / Q000201:enzymology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D012333:RNA, Messenger; D008071:Lipoprotein Lipase