翘嘴鲌生长激素基因侧翼2个微卫星位点与生长性状的关联分析

通过120尾同塘养殖翘嘴鲌体长和体质量的测定,以及生长激素基因(GH)侧翼的2个微卫星位点Cal-GH01和Cal-GH02基因型检测,分析了翘嘴鲌GH基因侧翼的2个微卫星多态性与生长性能的相关性。结果表明:Cal-GH01共检测到3个等位基因(404、407和410 bp)和6种基因型,等位基因407 bp是优势等位基因,407/407 bp是优势基因型;该微卫星位点多态信息含量为0.420,观测杂合度为0.207 2,属中度多态性位点。Cal-GH02共检测到6个等位基因(366、375、378、381、384和387 bp)和11种基因型,等位基因381 bp是优势等位基因,381/381 bp是优势基因型;该微卫星座位多态信息含量为0.450,观测杂合度为0.466 1,属中度多态座位。微卫星位点Cal-GH01的分析结果表明,404/407型个体占样本数的13.3%,其体长最长。407/410型个体占样本数的5%,其体质量最大。Cal-GH01不同基因型个体体长和体质量均有差异,但差异均不显著(P>0.05)。在微卫星位点Cal-GH02中,366/381型个体占样本数的3.3%,其体长和体质量均最大,其体质量显著大于其他基因型个体(P<0.05)。384/387型个体占样本数的2.5%,其体长和体质量均最小,其体长显著小于其他基因型个体(P<0.05)。翘嘴鲌GH基因多态性与生长性状存在关联,推测相关变异位点可作为翘嘴鲌生长的候选辅助标记。

Correlation analysis of growth traits and two microsatellite polymorphisms in flanking region of growth hormone gene in topmouth culter (Culter alburnus Basilewsky)

The body length and weight of 120 topmouth culter (Culter alburnus Basilewsky) cultured in the same pond were measured. The polymorphism information and correlation with growth traits of two microsatellite loci, Cal-GH01 and Cal-GH02, located in the flanking regions of the growth hormone (GH) gene were analyzed. The results showed that three Cal-GH01 alleles (404, 407 and 410 bp) and six genotypes could be detected. The 407 bp allele was the dominant allele, and 407/407 bp was the dominant genotype. The polymorphic information content of the microsatellite locus was 0.420, and the heterozygosity was 0.207 2. A total of six alleles (366, 375, 378, 381, 384 and 387 bp) and 11 genotypes were detected for Cal-GH02. The 381 bp allele was the dominant allele, and 381/381 bp was the dominant genotype. The polymorphic information content of the microsatellite locus was 0.450, and the heterozygosity was 0.466 1, which made it a moderately polymorphic locus. The associations between the polymorphisms of the two loci and growth traits were analyzed using general linear models. The analysis results for microsatellite locus Cal-GH01 showed that 404/407-type individuals accounted for 13.3% of the sample size and had the longest body length. The 407/410-type individuals accounted for 5% of the sample weight and were the heaviest. There were some differences in body length and body weight among the Cal-GH01 genotypes; however, the differences were not significant (P>0.05). For microsatellite locus Cal-GH02, 366/381-type individuals accounted for 3.3% of the number of samples, and their body length and body weight were the highest. Their weight was significantly higher than that of the other genotypes (P<0.05). 384/387-type individuals accounted for 2.5% of the sample size, and their body length and weight were the lowest. Their body length was significantly lower than that of other genotypes (P<0.05). In conclusion, we studied the genetic characteristics of two microsatellite loci in 120 fish sampled from the same pond. The correlation analysis for body length and body weight provided a scientific basis for marker-assisted selection for growth traits. Overall, there were associations between polymorphisms in the GH gene and the growth traits of C. alburnus. Therefore, the two microsatellite loci in GH gene could be used as markers for practical breeding programs for growth traits in C. alburnus.