Meta-analysis of intramuscular fat QTL in swine | 基于Meta分析的猪肌内脂肪QTL整合定位

Chino. 通过Meta分析，用数学模型分析与优化定位分散的猪肌内脂肪QTL，提高QTL定位的准确度和有效性，为猪肌内脂肪相关基因的精细定位和基因挖掘奠定基础。收集猪肌内脂肪QTL及其相关信息，以美国肉畜研究中心（USDA-MARC 2.0）公布的猪遗传连锁图谱为参考图谱，利用BioMercator2.1将各QTL映射到参考图谱上，构建新的整合图谱,得到QTL簇。对得到的QTL簇进行Meta分析，缩短置信区间，定位“真实”QTL(MQTL)，减少QTL的定位误差。收集了67个猪肌内脂肪QTL及相关信息，经比对、映射，构建新的整合图谱，发现了12个QTL簇。通过Meta分析，得到12个MQTL(MQTL1～MQTL12)，其图距比原平均图距缩小29.16%～87.40%,其中，MQTL3、MQTL5、MQTL6、MQTL7、MQTL9、MQTL12图距较原平均图距缩小比例均超过50%,其图距分别为7.76,6.72,5.20,19.45,15.61,9.37 cM。得到了12个猪IMF的MQTL,其图距比原平均图距均有不同程度缩小，最小仅5.20 cM，图距缩小比例最大可达87.40%,提高了QTL定位的准确度和有效性。

Inglés. A meta-analysis was performed for the quantitative trait loci (QTL) related to intramuscular fat (IMF) to estimate the number and refine the positions of QTL. An integrated map of IMF QTL in swine was established with the swine linkage map of USDA-MARC 2.0 as a reference map. IMF QTL were collected and projected to the reference map with the software BioMercator2.1. Meta-QTL were obtained by meta-analysis which reduced the QTL confidence intervals compared with individual QTL estimates. 67 IMF QTL were collected from 38 published papers. Twelve meta-QTL (MQTL1-MQTL12) as well as their corresponding markers were obtained. The 95% confidence intervals and the number of QTL were reduced compared with the QTL before the meta-analysis. The reduction in the confidence interval ranged from 29.16% to 87.40%. The 95％confidence interval of MQTL3, MQTL5, MQTL6, MQTL7, MQTL9, MQTL12 was 7.76, 6.72, 5.20, 19.45, 15.61, 9.37 cM, respectively. The confidence interval of meta-QTL was narrowed down by as much as 87.40% compared with that before the meta-analysis. The minimum 95％ confidence interval shrank to 5.20 cM in SSC6, with the marker SW2098 on the left and the marker SWR1384 on the right. These results offered a basis for gene mining and molecular breeding in swine.