A new single nucleotide polymorphism in the calpastatin (CAST) gene associated with beef tenderness

First we looked for putative causative mutations in the CAST and CAPN1 genes associated with meat tenderness and found a total of 31 and 7 polymorphisms, respectively, in the Parda de Montaña and Pirenaica breeds. Tenderness was not affected by mutations in CAPN1. However, three SNPs located at intron 5 (BTA7: g.98533962C>G on UMD 3.0), exon 7 (g.98535683A>G) and intron 12 (g.98545188T>A) of the CAST gene were significantly associated with meat tenderness at 7 days post-mortem in the Parda de Montaña breed. The haplotypes h2 and h5 showed significant associations with meat toughness being consistent with the SNP association results, which showed that the g.98535683A>G SNP in CAST might be the causative mutation of the effect found in this study. This mutation changes the amino acid sequence at position p.Thr182Ala (NM_174003). This amino acid substitution could affect the interacting regions between the calpastatin L-domain and calpain, and then could generate a more stable union between calpain and calpastatin.