NORSVIN (The Norwegian Pig Breeders Association), 2304 Hamar, Norway.
BMC Genomics. 2011 Jul 13;12:362. doi: 10.1186/1471-2164-12-362.
Boar taint is observed in a high proportion of uncastrated male pigs and is characterized by an unpleasant odor/flavor in cooked meat, primarily caused by elevated levels of androstenone and skatole. Androstenone is a steroid produced in the testis in parallel with biosynthesis of other sex steroids like testosterone and estrogens. This represents a challenge when performing selection against androstenone in breeding programs, without simultaneously decreasing levels of other steroids. The aim of this study was to use high-density genome wide association (GWA) in combination with linkage disequilibrium-linkage analysis (LDLA) to identify quantitative trait loci (QTL) associated with boar taint compounds and related sex steroids in commercial Landrace (n = 1,251) and Duroc (n = 918) breeds.
Altogether, 14 genome wide significant (GWS) QTL regions for androstenone in subcutaneous fat were obtained from the LDLA study in Landrace and 14 GWS QTL regions in Duroc. LDLA analysis revealed that 7 of these QTL regions, located on SSC 1, 2, 3, 7 and 15, were obtained in both breeds. All 14 GWS androstenone QTLs in Landrace are also affecting the estrogens at chromosome wise significance (CWS) or GWS levels, while in Duroc, 3 of the 14 QTLs affect androstenone without affecting any of the estrogens. For skatole, 10 and 4 QTLs were GWS in the LDLA analysis for Landrace and Duroc respectively, with 4 of these detected in both breeds. The GWS QTLs for skatole obtained by LDLA are located at SSC 1, 5, 6, 7, 10, 11, 13 and 14.
This is the first report applying the Porcine 60 K SNP array for simultaneous analysis of boar taint compounds and related sex hormones, using both GWA and LDLA approaches. Several QTLs are involved in regulation of androstenone and skatole, and most of the QTLs for androstenone are also affecting the levels of estrogens. Seven QTLs for androstenone were detected in one breed and confirmed in the other, i.e. in an independent sample, although the majority of QTLs are breed specific. Most QTLs for skatole do not negatively affect other sex hormones and should be easier to implement into the breeding scheme.
在未去势的雄性猪中，会观察到公猪异味，其特征是在煮熟的肉中有不愉快的气味/味道，主要是由于雄烯酮和粪臭素水平升高所致。雄烯酮是一种在睾丸中与其他性激素（如睾酮和雌激素）的生物合成同时产生的类固醇。这在进行繁殖计划中的雄烯酮选择时是一个挑战，因为同时会降低其他类固醇的水平。本研究的目的是使用高密度全基因组关联（GWA）结合连锁不平衡-连锁分析（LDLA）来鉴定与公猪异味化合物和相关性激素相关的数量性状基因座（QTL）在商业长白猪（n = 1251）和杜洛克猪（n = 918）品种中。
总共，从长白猪的 LDLA 研究中获得了 14 个皮下脂肪中雄烯酮的全基因组显著（GWS）QTL 区域，而杜洛克猪中则获得了 14 个 GWS QTL 区域。LDLA 分析表明，这 7 个 QTL 区域位于 SSC1、2、3、7 和 15 上，在两个品种中均有发现。长白猪中的 14 个全基因组显著的雄烯酮 QTL 也在染色体水平显著（CWS）或全基因组显著（GWS）水平上影响雌激素，而在杜洛克猪中，14 个 QTL 中有 3 个影响雄烯酮而不影响任何雌激素。对于粪臭素，在 LDLA 分析中，长白猪和杜洛克猪分别有 10 个和 4 个 QTL 达到全基因组显著水平，其中 4 个在两个品种中均有发现。通过 LDLA 获得的粪臭素全基因组显著 QTL 位于 SSC1、5、6、7、10、11、13 和 14 上。
这是首次应用 Porcine 60 K SNP 阵列同时分析公猪异味化合物和相关性激素，同时使用 GWA 和 LDLA 方法。多个 QTL 参与雄烯酮和粪臭素的调节，大多数雄烯酮的 QTL 也影响雌激素水平。在一个品种中检测到 7 个雄烯酮 QTL，并在另一个品种（即在独立样本中）得到确认，尽管大多数 QTL 是品种特异性的。大多数粪臭素的 QTL 不会对其他性激素产生负面影响，因此更容易纳入育种计划。
