Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2004
Publication Date: January 10, 2004
Citation: White, S.N., Page, B.T., Casas, E., Koohmaraie, M., Wheeler, T.L., Shackelford, S.D., Keele, J.W., Smith, T.P. 2004. Association of CAPN1 markers with beef tenderness in crossbred, multibreed populations. Proc.,Plant and Animal Genome Abstracts. P644. p. 232. Technical Abstract: The CAPN1 gene lies on chromosome 29 (BTA 29) and encodes the protease mu-calpain, which degrades myofibrillar proteins and is thought to be the most important enzyme involved in beef tenderness. Two CAPN1 SNPs (resulting in amino acid substitutions G316A and I530V) have previously been shown to be associated with meat tenderness in two unrelated resource populations that had evidence of QTL on BTA 29. Genotypes at these markers were analyzed in a third QTL resource family, sired by a Brahman x Hereford bull. Despite a segregating QTL detected on BTA 29 in this family, the bull was homozygous for both of the CAPN1 markers. This suggests the possibility that additional variation at this locus may be associated with tenderness. Three new CAPN1 SNP markers were developed that are informative in this bull, and all three are associated with tenderness as measured by Warner-Bratzler shear force (p<0.01) in this family. These data support the association of the CAPN1 locus with tenderness, but bring into question the usefulness of G316A and I530V for predicting tenderness traits in commercial populations. Therefore, these two original SNP were also tested in GPE cycle VII, an outbred, multisire, population comprised of seven Bos taurus breeds. Both G316A and I530V show highly significant association with Warner-Bratzler shear force (p<0.01) in GPE VII. These data demonstrate the extended usefulness of these tenderness-associated SNP markers outside the original QTL populations. However, further work is necessary to establish their importance in cattle of Bos indicus descent.