|Heaton, Michael - Mike|
|Smith, Timothy - Tim|
Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/16/2002
Publication Date: 10/16/2002
Citation: Page, B.T., Casas, E., Heation, M.P., Cullen, N.G., Hyndman, D.L., Morris, C.A., Crawford, A.M., Wheeler, T.L., Koohmaraie, M., Keele, J.W., Smith, T.P.L. Journal Animal Science. 2002. v. 80. p. 3077-3085. Interpretive Summary: This report presents evidence that SNPs determining amino acid variation of valine or isoleucine at position 530 and glycine or alanine at position 316 in the CAPN1 gene, are markers for meat tenderness variation. If the alternative genotypes can successfully predict meat tenderness phenotypes in larger, unrelated populations, it would represent the first example of a DNA test for genetic merit directly related to this trait, and would represent a valuable tool for cattle breeders to improve tenderness in cattle.
Technical Abstract: Micromolar calcium activated neutral protease (CAPN1) was evaluated as a candidate gene for a quantitative trait locus (QTL) on BTA29 affecting meat tenderness, by characterization of nucleotide sequence variation in the gene. Single nucleotide polymorphisms (SNPs) were identified by sequencing all 22 exons and 19 of the 21 introns in two sires (Piedmontese x Angus located at the U.S. Meat Animal Research Center in Clay Center, NE and Jersey x Limousin located at AgResearch in New Zealand) of independent resource populations previously shown to be segregating meat tenderness QTL on BTA29. The majority of the 38 SNPs were found in introns or were synonymous substitutions in the coding regions, with two exceptions. SNPs in exons 14 and 9 were predicted to alter the protein sequence by the substitution of isoleucine for valine in Domain III of the protein, and alanine for glycine in Domain II of the protein. The resource populations were genotyped for these two SNPs in addition to six intronic polymorphisms and two silent substitutions. Analysis of genotypes and shear force values in both populations revealed a difference between paternal CAPN1 alleles in which the allele encoding isoleucine at position 530 and glycine at position 316 associated with decreased meat tenderness (increased shear force values) relative to the allele encoding valine at position 530 and alanine at position 316 (p<.05). The association of maternal alleles with meat tenderness phenotypes is consistent with the hypothesis of CAPN1 as the gene underlying the QTL effect in two independent resource populations, and presents the possibility of using these markers for selective breeding to reduce the numbers of animals with unfavorable meat tenderness traits.