directed search for quantitative trait loci on chromosomes 4 and 7 in pigs

• Published in: Journal of animal science Vol. 76; no. 10; pp. 2560 - 2567
• Main Authors: Wang, L, Yu, T.P, Tuggle, C.K, Liu, H.C, Rothschild, M.F
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.10.1998; American Society of Animal Science; Oxford University Press
• Subjects: Animals; area; backfat; Biological and medical sciences; birth weight; Birth Weight - genetics; body weight; Chromosome Mapping; Classical genetics, quantitative genetics, hybrids; color; Crosses, Genetic; fat thickness; Female; firmness; Fundamental and applied biological sciences. Psychology; genes; genetic markers; Genetics; Genetics of eukaryotes. Biological and molecular evolution; growth; Hogs; linkage (genetics); liveweight gain; loci; Male; Meat - standards; meat quality; Microsatellite Repeats; muscles; quantitative traits; swine; Swine - genetics; Swine - growth & development; Vertebrata; Weaning; weaning weight; Weight Gain - genetics; Vertebrata; Mammalia; Genetic marker; Growth; Quantitative character; Chromosome 7; Artiodactyla; Chromosome 4; Ungulata; Carcass; Pig
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/1998.76102560x

Improvements in the porcine genetic map and availability of resource families to study performance traits in pigs have made it possible to reexamine previous findings that linked certain traits to genes or chromosomal regions. Previous studies suggested that chromosomes 4 and 7 may be associated with growth and performance traits. To confirm these previous results, an interval mapping-regression approach was used to determine whether quantitative trait loci (QTL) exist in the Iowa State University reference/resource families. Traits measured were birth weight; body weight at 21 d; weaning weight (weight at 42 d); average daily gain; backfat at the first, 10th, lumbar, and last ribs and average backfat thickness; loin eye area; meat color; marbling; and firmness. The total number of F2 pigs used ranged from 241 to 330 and came from five Chinese X American resource families. Five markers (S0001, SW871, S0175, S0214, and SW445) were genotyped and mapped on chromosome 4, and so were 10 markers (50064, tumor necrosis factor a [TNFalpha], S0102, S0078, S0158, S0066, SW304, SW1083, 50101, and S0212) on chromosome 7. Data were analyzed for each family (breed cross) separately and were also pooled. Experiment-wise thresholds were used to determine significance. Suggestive evidence of QTL on chromosomes 4 and 7 was observed for several traits in pooled and individual family analyses. Suggestive evidence of a QTL with a relatively large effect for average daily gain was detected on chromosome 4 in the pooled analysis. Significant (P <.05) evidence for QTL was seen on chromosome 7 for 10th-rib, last-rib, and average backfat thickness in the pooled data set in a region of the chromosome that was near TNFalpha. These results verify in part that chromosomes 4 and 7 contain QTL for growth and carcass traits.