Cloning and expression analysis of a cDNA encoding lipoprotein lipase from the liver of adult grass carp (Ctenopharyngodon idella)

A full-length cDNA coding lipoprotein lipase (LPL) was cloned from the liver of adult grass carp (Ctenopharyngodon idella) using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends approaches. The cDNA obtained was 2414 bp long with a 1524 bp open reading frame encoding 507 amino acids, including a putative signal peptide 21 amino acids long. The LPL protein has a calculated molecular weight of 57.77 kDa and an isolectric point of 8.132. The main domains of LPL, such as catalytic site, disulphide bridge, N-linked glycosylation site, heparin-binding domain, lipid-binding site and site of dimer formation, are basically conserved between the grass carp and other vertebrates. The tissue distribution of LPL mRNA in the liver, head kidney, mesenteric adipose tissue, heart and white muscle of adult grass carp was analysed using the semi-quantitative RT-PCR method using β-actin gene as an internal control; the result showed that the expressions of LPL mRNA were detected in all examined tissues of adult grass carp. The expression levels of LPL in the mesenteric adipose tissue were the highest among these tissues, followed by the liver and head kidney and the lowest expression was found in the heart and white muscle.