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.
Rohrer
G A
GA
U.S. Meat Animal Research Center, USDA, ARS, Clay Center, NE 68933, USA.
Keele
J W
JW
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