Abstract：High density lipoprotein binding protein (HBP) plays an important role in fat metabolism. Lipid is indispensable to fish energy material, and it is very important for carnivorous fish which has low efficiency to use carbohydrate, especially. The single nucleotide polymorphism(SNP) in HBP gene may affect the fat metabolism, and is correlated with growth traits. Studying the association between the SNP and growth traits can provide candidate markers for marker-assisted selection. In this study, partial genomic fragments of HBP gene were amplified based on the sequences of one available contig in the EST-SNP database of largemouth bass (Micropterus salmoides). Three single nucleotide polymorphism(SNP) mutations were identified after sequencing the PCR products of twenty individuals (H1: G+2782T, H2: T+2817C, H3: G+2857A), which were located in 3'non-coding region. For the three SNPs, the genotype and gene frequency of 165 largemouth bass were further assayed with the method of SnaPshot. Genetic structure was analyzed by POPGENE32 software. A general linear model(GLM) was used in the correlation analysis between SNPs and growth traits. The results showed that three locus were in Hardy-Weinberg equilibrium. The sites of H1 and H2 formed two haplotypes (A and B) and three genotypes (AA, AB, and BB). The sites of H1, H2 and H3 formed six diplotypes(D1, D2, D3, D4, D5 and D6). Association analysis showed that each SNP was not significantly associated with growth traits. The body weight and total length of genotype BB and AB were significantly different (P＜0.05). The body weight and total length of diplotypes D2 and D6 were significantly different (P＜0.05). Our data suggested a significant association between genetic variations in the largemouth bass HBP gene and growth traits. These results indicated that the SNP markers founded in HBP gene 3'non-coding region were candidate genetic markers, which can be used in future breeding programs of largemouth bass.
