Iowa State University Breeding/Physiology New Alleles in the Calpastatin Gene Associated with Improved Tenderness in Pork

Suggestive quantitative trait loci (QTL) affecting average Instron force and other tenderness measures were mapped to pig chromosome 2 (SSC 2) by using a three-generation intercross between Berkshire x Yorkshire (B x Y) pigs. Based on the QTL location, the Calpastatin (CAST) gene was considered to be a good candidate for the observed effects. Differences in the CAST gene sequences of the members of the B x Y intercross were analyzed. Two missense substitutions (changes affecting proteins) were identified. To test the hypothesis that at least one of these mutations was associated with differences in tenderness, individuals from F2 B x Y, and from a Duroc x Yorkshire (D x Y) intercross, were genotyped for the candidate gene differences and association studies were performed. The results provide significant support for the presence of new economically important alleles (gene forms) of the CAST gene affecting the Instron/Shear Force and the resulting meat quality. The significant effect of these markers on tenderness measures, will add them to the list of already discovered Halothane and RN markers, as a set of molecular tools developed to improve pork quality