|Zhang, Shu -|
|Knight, Travis -|
|Reecy, James -|
|Beitz, Donald -|
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2009
Publication Date: December 7, 2009
Citation: Zhang, S., Knight, T.J., Reecy, J.M., Wheeler, T.L., Shackelford, S.D., Cundiff, L.V., Beitz, D.C. 2009. Association of polymorphisms in the promoter I of bovine acetyl-CoA carboxylase-alpha gene with beef fatty acid composition. Animal Genetics. 41:417-420. Interpretive Summary: Reducing the amount of fat and the degree of saturation of fat in beef would improve the healthiness of beef products. One approach to manipulate fat in beef would be to identify genetic variation in fat synthesis. There are many regions of bovine chromosome 19 that are related to fat traits. This study identified variation in the gene for one of the enzymes involved in fat synthesis. This variation could be used to select for cattle that would have more healthful beef due to reduced saturated fat.
Technical Abstract: The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the promoter I (PI) region of bovine acetyl-CoA carboxylase-alpha (ACACA) gene and evaluate the extent to which they were associated with lipid-related traits and fatty acid composition of beef. Eight novel SNPs were identified, which were AJ276223:g.2064T>A (SNP1), g.2155C>T (SNP2), g.2203G>T (SNP3), g.2268T>C (SNP4), g.2274G>A (SNP5), g.2340A>G (SNP6), g.2350T>C (SNP7), and g.2370A>G (SNP8). Complete linkage disequilibrium was observed among SNP1, 2, 4, 5, 6, and 8. Phenotypic data were collected from 573 cross-bred steers with 6 sire breeds, including Hereford, Angus, Brangus, Beefmaster, Bonsmara, and Romosinuano. The associations of genotypes determined by SNPs with lipid content, marbling score, adjusted backfat thickness, and fatty acid composition of longissimus dorsi muscle (LM) were investigated. The genotypes of SNP1/2/4/5/6/8 were significantly associated with adjusted backfat thickness. The g.1338G>T genotype was significantly associated with triacylglycerols (TAG) and total lipid contents, marbling score, and fatty acid composition of LM in progeny of Bonsmara bulls. Bonsmara-sired cattle with g.1338GG genotype had greater concentrations of TAG, total lipid, individual saturated fatty acid (SFA), total SFA, individual monounsaturated fatty acid (MUFA) except myristoleic acid (C14:1), and total MUFA than did Bonsmara-sired cattle with g.1338GT genotype. The g.2350T>C genotype was significantly associated with fatty acid composition of LM. Cattle with genotype g.2350TC had greater contents of several fatty acids, including myristic acid (C14:0), C14:1, and palmitoleic acid, in LM than did cattle with genotype g.2350CC. Our results suggested that the SNPs in the PI region of ACACA gene are associated with variation in the fatty acid contents in LM.