猪肉pH值相关QTL整合定位与基因关联分析

为了整合与优化猪肉pH值相关数量性状位点(quantitative trait loci，QTL)，为分子标记辅助选择奠定基础。采用Meta分析，整合猪pH相关QTL，并对已知候选基因与“真实”QTL进行关联。收集猪肉pH值相关QTL，将其映射到美国肉畜研究中心(USDA-MARC 2.0)公布的猪遗传连锁图谱，构建新的整合图谱，新图谱中的QTL簇经Meta分析，聚合为“真实”QTL (MQTL)。进一步将已知候选基因映射到整合图谱，比较候选基因与各“真实”QTL的位置差异，分析其关联性。结果显示：224个原始QTL聚合成37个QTL簇，通过Meta分析，得到37个“真实”QTL。“真实”QTL的置信区间1.35~25.32 cM，相比原始QTL缩短29.20%~92.36%。其中，MQTL35、MQTL16、MQTL10、MQTL4和MQTL17的置信区间均在5 cM以内，且分别是由7、8、4、5、7个QTL聚合而成，具有较高的精确度和一致性。LYZ、RYR1、VTN、MYPN和PRKAG3基因映射到整合图谱后，分别定位在MQTL13、MQTL18、MQTL29、MQTL32和MQTL34置信区间内，可将其作为关键区域，开展深入研究工作。

Meta-Analysis of pH Value QTL in Swine

In this study, a Meta-analysis was conducted for the Quantitative Trait Loci （QTL） related to pH value to estimate the number and refine the positions of QTL. pH value QTL were collected and projected to the swine linkage map of USDA-MARC 2.0 to establish an integrated map. Meta-QTL （MQTL） were obtained by meta-analysis which reduced the confidence intervals. Positions of candidate genes and meta-QTL were compared to reckon the precision of meta-QTL. The results showed that 224 pH value QTL were collected from 27 published papers and an integrated map was established with the software BioMercator2.1. 37 meta-QTL were obtained, with which the 95% confidence intercal rate changed from 29.20% to 92.36%. For instance, the MQTL4, MQTL17 was only 1.35 cM, 2.86 cM, 4.45 cM, ranged from 1.35 cM to 25.32 cM, and the reduction confidence interval of MQTL35, MQTL16, MQTL10, 4.68 cM, 4.80 cM, respectively. The position of LYZ, RYR1, VTN, MYPN and PRKAG3 gene projected to the integrated map was in the confidence interval of MQTL13, MQTL18, MQTL29, MQTL32 and MQTL34. These results offered more precise QTL positionestimates and a basis for molecular breeding in swine.