A single-nucleotide polymorphism on Calpain-1 is associated with
meat tenderness in cattle
N.G. CULLEN, B.T. PAGE, C.A. MORRIS, S.M. HICKEY AND P.M. DOBBIE
AgResearch, Ruakura Research Centre, PB 3123, Hamilton, New
Zealand
E-Mail:
NZSAP 2003 Abstract No. 14
Proceedings of the New Zealand Society of Animal Production
63: 53-56
Variability in tenderness remains a major concern to the meat
industry, and our objective was to identify genetic effects on beef meat
tenderness, in animals treated alike, and under similar
post-mortem processing conditions. A quantitative trait locus
(QTL) for beef tenderness has been located on the same region of
chromosome 29 in a United States Department of Agriculture (USDA) study
and in our research. Micro-calpain, or calcium-activated neutral
protease (CAPN1), has been identified as a candidate gene. The
calpain/calpastatin system is involved in the change of tenderness with
time, by regulating post-mortem proteolysis. The CAPN1 gene was
sequenced by USDA workers who identified single-nucleotide polymorphisms
(SNPs) in two exons. These results were followed up as part of the
AgResearch Jersey-Limousin Beef QTL trial, where steak samples were
obtained from the longissimus dorsi of 416 animals slaughtered at
about two years of age. The segregating USDA and NZ families were both
heterozygous for one of these SNPs, on exon 9, and this region was
predicted to alter the protein sequence by the substitution of alanine
for glycine in Domain II. Both families were genotyped for these two
SNPs, as well as for six intronic polymorphisms, to define haplotypes.
Analysis of tenderness measurements in the NZ data (n=81 animals) showed
a difference between paternal CAPN1 haplotypes, with the SNP encoding
alanine at amino acid number 316 being associated with more tender meat
(decreased shear force) relative to the SNP encoding glycine
(P<0.00001). The association of the maternal haplotypes with meat
tenderness phenotypes (P<0.01) was also consistent with the
hypothesis of CAPN1 as the gene underlying the QTL effect. The sire and
dam effects together accounted for over 30% of the residual variance in
tenderness. Our results show that a single SNP test in the laboratory
can distinguish genetically tender and genetically tough animals at any
age.
Keywords: NZSAPAB;
cattle; meat; tenderness; QTL; micro-calpain; SNP
Last Updated 8/07/2004
