Polymorphisms of the lipoprotein lipase gene of red seabream, Pagrus major

Abstract

Polymorphism of the lipoprotein lipase (LPL) gene which plays an important role in regulation of lipid deposition was analysed in two red seabream (pagrus major) populations (KF4, cultured KORDI line, n = 100; JPN, imported from Japan, n = 100). We amplified a DNA fragment (1,091 bp) including the exon 2 region of the LPL gene, and conducted PCR-RFLP analysis using MspI and AluI. The PCR products were also sequenced. Two alleles (A and B) were found in MspI digestion and five alleles (A, B, C, D and E) in AluI digestion. The sequenced data revealed four nucleotide substitutions including one transversion at the MspI recognition site (nt 2,235, C→G) and three transitions at the AluI recognition sites (nt 1,727, A→G; nt 2,319, C→T; nt 2,319, T→C. Among them, substitutions at the nt 2,235 and 2,319 sites which are located in the exon 2 were proved to be silent point mutations. MspI polymorphism resulted in 3 genotypes, and the allele frequency was significantly different between the two fish populations, KF4 and JPN. In the case of AluI polymorphism, the 5 alleles (A, B, C, D, E) comprised 12 genotypes of the 5 alleles. KF4 population, alleles D and E were specific to the LPL gene polymorphisms would be useful DNA markers for red seabream population.