Rohrer G A, Keele J W
U.S. Meat Animal Research Center, USDA, ARS, Clay Center, NE 68933, USA.
J Anim Sci. 1998 Sep;76(9):2247-54. doi: 10.2527/1998.7692247x.
One of the major determining factors in the price of market hogs today is backfat depth. Therefore, identification of regions of the genome affecting this trait could be very useful to the swine industry. A large resource population (n = 540) was developed by backcrossing F1 Meishan-White composite females to either Meishan or White composite boars. A genomic scan was conducted by genotyping all animals with microsatellite markers spaced at approximately 20-cM intervals across the entire porcine genome. Breed of origin for all chromosomal segments was determined using multipoint linkage procedures, and a least squares regression analysis was conducted. Nominal P-values were converted to a genome-wide level of significance to adjust for the numerous tests conducted. Traits analyzed were backfat depths at the first rib (FRIB); 10th rib (10th); last rib (LRIB); last lumbar (LLUM) vertebra; the average of FRIB, LRIB, and LLUM (AVBF); and weight of leaf fat (LEAF). Significant quantitative trait loci (QTL) were detected on chromosomes 1, 7, and X. Suggestive evidence for QTL was present on chromosomes 5, 8, 9, 10, 13, and 14. Genotypic means for the loci detected indicated a predominantly additive mode of inheritance. Meishan alleles produced fatter pigs for all loci except those on chromosomes 7 and 10. Additional research should be conducted to refine the estimated position of each QTL and its effect and determine epistatic interactions. These loci should be evaluated in other germplasms to determine whether allelic variation at the QTL exists in other breeds.
当前，影响市场肉猪价格的主要决定因素之一是背膘厚度。因此，确定影响该性状的基因组区域对养猪业可能非常有用。通过将F1梅山-大白合成系母猪与梅山或大白合成系公猪回交，构建了一个大型资源群体（n = 540）。利用在整个猪基因组中以约20厘摩间隔分布的微卫星标记对所有动物进行基因分型，进行了基因组扫描。使用多点连锁程序确定所有染色体片段的起源品种，并进行了最小二乘回归分析。将名义P值转换为全基因组显著性水平，以校正所进行的大量测试。分析的性状包括第一肋处的背膘厚度（FRIB）；第10肋处（10th）；最后一肋处（LRIB）；最后腰椎（LLUM）处；FRIB、LRIB和LLUM的平均值（AVBF）；以及板油重量（LEAF）。在第1、7和X染色体上检测到显著的数量性状位点（QTL）。在第5、8、9、10、13和14染色体上存在QTL的暗示性证据。所检测位点的基因型均值表明主要是加性遗传模式。除了第7和10染色体上的位点外，梅山等位基因在所有位点上都使猪更肥。应进行进一步研究以细化每个QTL的估计位置及其效应，并确定上位性相互作用。应在其他种质中评估这些位点，以确定其他品种中是否存在QTL的等位基因变异。
