quantitative trait locus genome scan for porcine muscle fiber traits reveals overdominance and epistasis

• Published in: Journal of animal science Vol. 86; no. 12; pp. 3290 - 3299
• Main Authors: Estellé, J, Gil, F, Vázquez, J.M, Latorre, R, Ramírez, G, Barragán, M.C, Folch, J.M, Noguera, J.L, Toro, M.A, Pérez-Enciso, M
• Format: Journal Article
• Language: English
• Published: Champaign, IL American Society of Animal Science 01.12.2008; Am Soc Animal Sci
• Subjects: alleles; Animal productions; Animals; Biological and medical sciences; Chromosome Mapping; chromosomes; diameter; epistasis; Epistasis, Genetic; Female; Fundamental and applied biological sciences. Psychology; gene interaction; Genes, Dominant; genetic markers; genetic variation; genome; genomics; histochemistry; Male; meat quality; muscle fibers; Muscle Fibers, Skeletal - physiology; pork; quantitative trait loci; Quantitative Trait Loci - genetics; swine; Swine - genetics; Swine - physiology; swine breeds; Terrestrial animal productions; Vertebrates; Farming animal; muscle fiber; Fiber; Epistasis; overdominance; Pig; Vertebrata; Meat animals; Mammalia; quantitative trait locus; Muscle; Artiodactyla; Genome; Locus; Ungulata
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2008-1034

Muscle histochemical characteristics are decisive determinants of meat quality. The relative percentage and diameters of the different muscular fiber types influence crucial aspects of meat such as color, tenderness, and ultimate pH. Despite its relevance, however, the information on muscle fiber genetic architecture is scant, because histochemical muscle characterization is a laborious task. Here we report a complete QTL scan of muscle fiber traits in 160 animals from a F₂ cross between Iberian and Landrace pigs using 139 markers. We identified 20 genome regions distributed along 15 porcine chromosomes (SSC1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and X) with direct and(or) epistatic effects. Epistasis was frequent and some interactions were highly significant. Chromosomes 10 and 11 seemed to behave as hubs; they harbored 2 individual QTL, but also 6 epistatic regions. Numerous individual QTL effects had cryptic alleles, with opposite effects to phenotypic pure breed differences. Many of the QTL identified here coincided with previous reports for these traits in the literature, and there was overlapping with potential candidate genes and previously reported meat quality QTL.