镜鲤体质量和体长的QTL定位研究

Quantitative trait loci analysis for body weight and standard length in mirror carp

以镜鲤(Cyprinus carpio L.)全同胞家系为材料,用940对微卫星(SSR)标记进行基因组扫描,采用半同胞家系的分析策略对体质量(BW)和体长(SL)进行QTL定位分析。QTL检测显示:基于父系的QTL分析,共检测到8个QTL区间。5个与体质量相关的QTL区间中,1个QTL为95%基因组水平(genome-wide)显著性,位于LG26连锁群,其他4个QTL均为95%染色体水平(chromosome-wide)显著性;3个与体长相关的QTL区间与体质量的QTL区间重叠,其中,1个QTL为99%基因组水平显著性,其余2个QTL均为95%染色体水平显著性。基于母系的QTL分析,共检测到11个QTL区间。6个与体质量相关的QTL区间中,1个QTL为99%基因组水平显著性,位于LG26,2个QTL为99%染色体水平显著性,其余3个QTL均为95%染色体水平显著性;5个与体长相关的QTL中有4个与体质量QTL区间重叠,其中,1个QTL为99%基因组水平显著性,1个QTL为99%染色体水平显著性,其余3个QTL均为95%显著性染色体水平。结果表明,在LG26上,存在着与体质量和体长都显著相关的QTL区间,且均达到基因组显著性水平,最小置信区间为3 cM。此QTL结果可以应用于鲤鱼分子标记辅助育种。

Body weight and standard length traits are complex and important economic traits,and are also targets for selective animal breeding.Our objective was to identify QTL associated with body weight（BW） and standard length（SL） traits.We conducted a whole genome scan on 190 progeny from a full-sib family using 940 microsa-tellite markers.We conducted half-sib mapping using GridQTL software.We obtained 8 QTL distributed across 5 linkage groups（LG） during sire-based QTL analysis.For BW,5 QTL were identified,of which 1 QTL occurred at the 95% genome-wide level,and was located at LG26.The remaining 4 QTL were at the 95% chromosome-wide level,explaining 12.5%–32.6% of phenotypic variance.For SL,3 QTL overlapped with the BW QTL intervals.One QTL was identified at the 99% genome-wide level,and 2 QTL were at the 95% chromosome-wide level,ex-plaining 18.4%–40.9% of phenotypic variance.During dam-based QTL analysis,we identified 11 QTL that were distributed across 7 LGs.Six QTL were associated with BW,of which one was at the 99% genome-wide level and was also located at LG26.Two QTL were identified at the 99% chromosome-wide level,leaving 3 QTL at the 95% chromosome-wide level,accounting for 15.7%–37.6% of phenotypic variance.For SL,5 QTL were identified,of which 4 were the same marker or had a similar confidence interval with BW.Among these,1 QTL was identified at the 99% genome-wide level,1 QTL was at the 99% chromosome-wide level,and 3 QTL were at the 95% chro-mosome-wide level,explaining 16.7%–39.5% of phenotypic variance.Our results suggest that the most significant QTL maps to LG26 and is significant at the genome-wide level in both the sire and the dam-based analyses.The minimum confidence interval was only 3 cM,which can be used during molecular marker assisted selection（MAS） in mirror carp.Our results provide a useful reference for further candidate gene research and MAS in mirror carp.