Largemouth bass(Micropteruss almoides) is a primary cultured fish species in China,with annual production of 3.4 × 105 tons.Growth is one of the most crucial economic traits of all aquaculture species,but the molecular mechanisms involved in the growth of largemouth bass are poorly understood.Investigating the correlations between single nucleotide polymorphism (SNP) and growth traits can provide candidate markers for molecular marker-assisted selection.The objective of this study was to develop EST-SNPs from the transcriptome database and analyze their correlation with growth traits in largemouth bass.The transcriptome of muscle tissue from the fast-growing and slow-growing groups were sequenced using RNA-seq technology.A total of 54.06 million and 54.74 million qualified Illumina read pairs were gained for the fast-growing and slow-growing groups,respectively,giving rise to 84 602 and 88 329 contigs,respectively.17 376 and 15 273 potential SNPs were detected in the slow-growing and fast-growing groups,respectively.The mutation types of A,C,G,T base ranged from 1 057 to 5 573,and C/T and A/G type accounted for the largest ratio (more than 30％).The fish from Youlu No.1 largemouth bass population were used for marker-trait correlation analysis,which were hatched at the same time and cultured under the same rearing and management conditions at the Xinxu Fish Farm.At 11 months,430 individuals of Youlu No.1 largemouth bass were randomly selected and sampled for marker-trait correlation analysis.75 putative SNPs were selected to validate in 60 fish selected from both ends of the weight gain distribution in 430 individuals by SnaPshot technology.Among them,37 SNPs (49.3％) were genotyped successfully.A general linear model was established for correlation analysis between different genotypes at SNP loci and various growth traits using spss 19.0 software.At the position of CL1452.Contig9_All-847,individuals with the CC genotype had significantly greater values for body weight,total length and caudal peduncle length than those with the TT genotypes (P ＜ 0.05).Individuals with the CC genotype had significantly greater values for body depth and head length than those with the TT or CT genotypes (P ＞ 0.05).Other SNP loci were not significantly correlated with growth traits.Genetic structure was analyzed by POPGENE32 software.The average expected heterozygosity (Ho) and polymorphism information content (PIC) for 10 SNPs was 0.459 and 0.356 in the Youlu No.1 largemouth bass population,respectively,which suggested that the Youlu No.1 largemouth bass population had a relatively high level of genetic diversity.Chi-square test showed that four SNP loci (CL1328.Contigl_All-3 028,CL1115.Contig2_All-1357,Unigene14288_All-228 and CL1339.Contig2_All-844) were not in Hardy-Weinberg equilibrium in Youlu No.1 largemouth bass population.The growth-related CL1452.Contig9_All-847 locus might be a useful candidate molecular marker for largemouth bass molecular marker-assisted selection.
NETL
NSTL
维普
万方数据
