GENETIC AND GENOMIC APPROACHES TO IMPROVE EFFICIENCY OF SWINE PRODUCTION AND PRODUCT QUALITY
Location: Reproduction Research
Title: Relationships among calpastatin single nucleotide polymorphisms, calpastatin expression and tenderness in pork longissimus
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 2, 2009
Publication Date: October 1, 2009
Citation: Lindholm-Perry, A.K., Rohrer, G.A., Holl, J.W., Shackelford, S.D., Wheeler, T.L., Koohmaraie, M., Nonneman, D.J. 2009. Relationships among calpastatin single nucleotide polymorphisms, calpastatin expression and tenderness in pork longissimus. Animal Genetics. 40(5):713-721.
Interpretive Summary: The identification of predictive DNA markers for pork quality will allow U.S. pork producers and breeders to select genetically superior animals for production of high quality, consistent meat. Pork tenderness is a highly heritable trait and several genomic regions associated with tenderness have been identified in different commercial-type pig populations. A region on chromosome 2 associated with tenderness is positioned over the calpastatin gene. Calpastatin is the specific endogenous inhibitor of calpains, the primary cause of post mortem tenderization of meat. We analyzed several markers in the calpastatin gene in Duroc-Landrace and Duroc-Landrace-Large White populations and found three were significantly associated with slice shear force. The levels of mRNA expression of calpastatin in muscle were positively correlated with slice shear force, suggesting that the causative variation alters the amount of calpastatin, thus affecting tenderness. These data provide publicly available genetic markers associated with slice shear force that may be useful to the swine industry for marker assisted selection of animals with superior tenderness.
Genome scans in the pig have identified a region on chromosome 2 (SSC2) associated with tenderness. Calpastatin is a likely positional candidate gene in this region because of its inhibitory role in the calpain system that is involved in postmortem tenderization. Novel single nucleotide polymorphisms (SNP) in calpastatin were identified and used to genotype a population (n = 1042) of Duroc-Landrace-Yorkshire swine for association with longissimus lumborum slice shear force (SSF) measured at day 7 and 14 postmortem. Three genetic markers residing in the calpastatin gene were significantly associated with slice shear force (p<0.0005). Haplotypes constructed from markers in the calpastatin gene were significantly associated with slice shear force (F-ratio = 3.93; p-value = 0.002). The levels of mRNA expression of calpastatin in the longissimus lumborum of 118 animals also were evaluated by real-time RT-PCR and were correlated with slice shear force (r2 = 0.153, p = 0.009), suggesting the causative variation alters expression of calpastatin, thus affecting tenderness. In summary, these data provide evidence of several significant, publicly available SNP markers associated with slice shear force that may be useful to the swine industry for marker assisted selection of animals that have more tender meat.