Genomic structure, tissue expression and single nucleotide polymorphisms of lipoprotein lipase and hepatic lipase genes in Chinese perch

Abstract

Chinese perch, an obligate piscivorous fish, could serve as an excellent model system for studies on the diversification of lipoprotein lipase (Lpl) and hepatic lipase (Hl) genes. In this study, we characterized the genomic structure, tissue expression and single nucleotide polymorphisms of Lpl and Hl genes in Chinese perch (Siniperca chuatsi). Consistent with findings in other vertebrates, Chinese perch Lpl gene consisted of ten exons and nine introns, and Hl gene consisted of nine exons and eight introns. The promoter region of Hl gene was not highly homologous to that of Lpl gene in Chinese perch. The mRNA expression of Lpl in Chinese perch was the highest in adipose tissue, followed by liver, brain, intestine and muscle, and the lowest in spleen, whereas Hl was almost exclusively expressed in liver. These results suggested that Chinese perch Lpl and Hl might be derived from an early duplication of an ancestral gene. Polymorphisms of Lpl and Hl genes were examined in feeders and non-feeders of dead prey fish by direct sequencing of these genes in 130 fish from each group. Three SNPs (A1220T, G1221T and C1224G) were identified in Lpl gene, whereas none was identified in Hl gene. Diplotype 2 in Lpl gene was significantly correlated with acceptance of dead prey fish.