Introduction
The heightened interest in meat (muscle) quality has led to investigations into the physiological and genetic controls of these economically important traits. Often studies in livestock are modeled after known rodent or human genetic markers associated with diseases, which may also be related to body composition or changes in energy metabolism. Genetic markers characterized in other species serve as guides or "candidate" genes for investigation of the phenotypic differences found in swine.
Although several genetic markers and quantitative trait loci (QTL) affecting meat quality and performance traits have been detected in the pig (for review see Rothschild and Plastow, 1999), the quest continues to identify markers that explain significant variation in these traits of economic importance. As more information becomes available in swine molecular genetics, there exists a need to analyze associations between these markers and phenotypes in individual genetic lines or populations. The objective of this study was to determine the association between variation found in performance, carcass, and meat quality traits and four candidate genes of interest in different pig populations.