Rohrer G A, Thallman R M, Shackelford S, Wheeler T, Koohmaraie M
USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE, USA.
Anim Genet. 2006 Feb;37(1):17-27. doi: 10.1111/j.1365-2052.2005.01368.x.
A genome scan was conducted on 370 F2 Duroc-Landrace pigs. Microsatellite markers (n = 182) were genotyped across the entire F2 population, all F1 parents and the paternal grandparents. Breed of origin of all chromosomal segments inherited in F2 progeny were predicted using GenoProb, where genotypic data, genetic maps and extended pedigrees were used as inputs. Statistical tests for quantitative trait loci (QTL) associations were conducted on 41 phenotypes with SAS using output from GenoProb for genotypic data. Fixed effects included sex and age at slaughter. For certain analyses carcass weight, RYR1 genotype and/or PRKAG3 genotype were also included as covariates. Subjective and objective measures of pork colour, marbling and tenderness were recorded, as well as measures of carcass fatness and muscularity. Test results were adjusted to a genome-wide level of significance. Five genomic regions presented significant evidence for QTL at chromosome 1 positions 6 cM (intramuscular fat) and 67 cM (Hunter L*), chromosome 2 position 62 cM (taste panel tenderness), chromosome 17 position 50 (loineye area and image analysis estimated loineye area) and X position 87 cM (carcass weight). Sixty-six suggestive associations were detected. Fourteen of these associations were within the regions with significant QTL on chromosomes 2, 17 and X, and the remaining 52 associations resided in 29 other regions on 13 different chromosomes of the porcine genome. The chromosome 2 region of 60-66 cM was associated with all measures of pork tenderness and the region on chromosome 17 (32-39 cM) was associated with both measures of intramuscular fat and loineye area. After verification, the QTL for marbling and tenderness should be useful in commercial production to improve pork quality as the population was developed from two of the three most utilized breeds of swine in the USA.
对370头F2代杜洛克-长白猪进行了基因组扫描。在整个F2群体、所有F1亲本和父系祖父母中对182个微卫星标记进行了基因分型。使用GenoProb预测F2后代中所有遗传的染色体片段的起源品种，其中将基因型数据、遗传图谱和扩展系谱用作输入。使用GenoProb输出的基因型数据，在SAS中对41种表型进行了数量性状位点（QTL）关联的统计检验。固定效应包括性别和屠宰时的年龄。对于某些分析，胴体重量、RYR1基因型和/或PRKAG3基因型也作为协变量纳入。记录了猪肉颜色、大理石花纹和嫩度的主观和客观测量值，以及胴体脂肪和肌肉度的测量值。将测试结果调整到全基因组显著水平。五个基因组区域在染色体1的6 cM（肌内脂肪）和67 cM（亨特L*）、染色体2的62 cM（品尝小组嫩度）、染色体17的50（眼肌面积和图像分析估计的眼肌面积）和X染色体的87 cM（胴体重量）位置呈现出QTL的显著证据。检测到66个提示性关联。其中14个关联位于染色体2、17和X上具有显著QTL的区域内，其余52个关联位于猪基因组13条不同染色体上的29个其他区域。染色体2的60 - 66 cM区域与猪肉嫩度的所有测量值相关，染色体17的区域（32 - 39 cM）与肌内脂肪和眼肌面积的测量值均相关。经过验证，由于该群体是由美国最常用的三个猪品种中的两个培育而来，大理石花纹和嫩度的QTL在商业生产中应有助于提高猪肉品质。
