Identification of quantitative trait loci affecting carcass composition in swine: II. Muscling and wholesale product yield traits.
A genomic scan was conducted on 540 reciprocal backcross Meishan x White composite pigs for hot carcass weight (HCWT); loin eye area (LOIN); carcass length (CRCL); belly weight (BELLY); and weight of trimmed ham, loin, picnic, and Boston butt adjusted to a constant live (TWPLWT) or carcass (TWPCWT) weight. Genetic markers spanned the entire porcine linkage map and were spaced at approximately 20-cM intervals. Grandparental 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 number of tests actually conducted. Seven associations were significant at the genome-wide level relating to chromosomes 1 (SSC 1), 7 (SSC 7), and X (SSC X). The SSC 1 region affected LOIN, TWPLWT, and TWPCWT; SSC 7 affected HWCT and CRCL; and SSC X affected TWPLWT and TWPCWT. Twelve associations relating to seven chromosomal regions (including SSC 1 and X) presented suggestive evidence for quantitative trait loci (QTL), and many of these regions are likely to contain QTL. Chromosomes 8 and 14 had two and three traits with suggestive evidence for QTL, respectively. Many pleiotropic effects were detected for regions on SSC 1, 7, 14, and X in this study and a companion study looking for fat deposition QTL in the same population. In addition, SSC 4 was nearly significant for CRCL in the same region identified as affecting backfat in a wild boar x Large White population. These results expand our knowledge of the inheritance of quantitative traits and are directly relevant to composite populations containing Meishan germplasm.
U.S. Meat Animal Research Center, USDA, ARS, Clay Center, NE 68933, USA.
G A
GA
Rohrer
J W
JW
Keele
D000483:Alleles; D000818:Animals; D001823:Body Composition / Q000235:genetics*; D001947:Breeding; D002874:Chromosome Mapping / Q000662:veterinary; D005260:Female; D005819:Genetic Markers; D016678:Genome; D005838:Genotype; D008297:Male; D008460:Meat / Q000592:standards*; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development*; D010641:Phenotype; D019655:Quantitative Trait, Heritable; D013552:Swine / Q000235:genetics* / Q000254:growth & development
D005819:Genetic Markers