Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2013
Publication Date: 4/1/2014
Publication URL: http://handle.nal.usda.gov/10113/61186
Citation: Casas, E., Duan, Q., Schneider, M.J., Shackelford, S.D., Wheeler, T.L., Cundiff, L.V., Reecy, J.M. 2014. Polymorphisms in the calpastatin and mu-calpain genes associated with beef iron content. Animal Genetics. 45(2):283-284. DOI: 10.1111/age.12108. Interpretive Summary: Genetic markers in two genes (Calpastatin and mu-Calpain) have previously been associated with meat tenderness in beef cattle. These markers have only been associated with meat tenderness; however, there is no information if these markers could be associated with other traits of the meat. In this study we determined these genetic markers to be associated with levels of iron in muscle. Animals predicted, based on the genetic markers, to have tender meat had lower levels of iron in muscle. The association of these genetic markers with meat tenderness and with iron levels could imply an association between meat tenderness and iron levels in muscle. Further studies would be needed to ascertain if selection based on meat tenderness would have an indirect effect on iron levels in muscle.
Technical Abstract: The objective of this study was to assess the association of markers at the CAST and CAPN1 genes with iron stored in muscle fibers in a population of beef cattle. The population consisted of a total of 259 steers produced by inseminating Hereford, Angus, or MARC III cows (¼ Hereford, ¼ Angus, ¼ Red Poll, and ¼ Pinzgauer) with semen from Beefmaster, Brangus, Bonsmara, Romosinuano, Hereford, and Angus sires. Total iron and heme iron concentrations were measured in the population. Commercially available markers in the CAST and CAPN1 genes were used to assess their association with iron levels. The mean and standard error for iron and heme iron content in the population was 35.6 ug ± 1.3 and 27.1 ug ± 1.4, respectively. Significant associations (P< 0.01) of markers in the CAST and CAPN1 genes were observed for iron and heme iron content. For CAST, animals with the CC genotype had higher levels of iron and heme iron in muscle. Individuals with the CT and TT genotypes had similar amounts of iron and heme iron in muscle. For CAPN1, individuals with the CC and CT genotypes had similar amount of iron and heme iron, and animals with the TT genotype had higher concentrations of iron and heme iron than animals with the CC and CT genotypes. Genotypes known to be associated with tougher meat were associated with higher levels of iron concentration.