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United States Department of Agriculture

Agricultural Research Service

Research Project: REDUCING COST OF EFFICIENT BEEF PRODUCTION Title: Significant associations of stearoyl-CoA desaturase (SCD1) gene with fat deposition and composition in skeletal muscle

Authors
item Jiang, Z -
item Michal, J -
item Tobey, D -
item Daniels, T -
item Rule, D -
item Macneil, Michael

Submitted to: International Journal of Biological Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 25, 2008
Publication Date: September 25, 2008
Citation: Jiang, Z., Michal, J.J., Tobey, D.J., Daniels, T.F., Rule, D.C., Macneil, M.D. 2008. Significant associations of stearoyl-CoA desaturase (SCD1) gene with fat deposition and composition in skeletal muscle. International Journal of Biological Sciences 4(6):345-351.

Interpretive Summary: Elevated stearoyl-CoA desaturase (SCD1) activity contributes to increased fatness and amount of monounsaturated fatty acids in lipids of skeletal muscle. These factors then contribute to insulin resistance in obese people with type 2 diabetes. We annotated the bovine SCD1 gene and identified 3 single nucleotide polymorphisms (SNPs) in its 3’untranslated region (UTR). Genotyping these SNPs on a Wagyu x Limousin reference population revealed that among 12 phenotypes, the SCD1 gene was significantly associated with six fat deposition and fatty acid composition traits in skeletal muscle. We found high stearoyl-CoA desaturase activity was positively correlated with intramuscular fat (marbling) score, and amounts of monounsaturated fatty acids and conjugated linoleic acid content, but negatively correlated with the quantity of saturated fatty acid. The proximity of the polyadenylation signal site was found to be highly conserved among human, cattle and pig, indicating the region may contain functional elements involved in posttranscriptional control. Thus, we provide solid evidence to support SCD1 gene as a critical player in skeletal muscle fat metabolism.

Technical Abstract: Gene expression studies in humans and animals have shown that elevated SCD1 activity is associated with increased fat accumulation and monounsaturation of lipids in skeletal muscle, both of which are pathobiological contributors to insulin resistance in patients with obesity and type 2 diabetes. However, results of the two-reported association studies in humans are inconsistent. In the present study, we annotated the bovine SCD1 gene and identified 3 single nucleotide polymorphisms (SNPs) in its 3’untranslated region (UTR). Genotyping these SNPs on a Wagyu x Limousin reference population revealed that among 12 phenotypes, the SCD1 gene was significantly associated with six fat deposition and fatty acid composition traits in skeletal muscle. In particular, we confirmed that the high stearoyl-CoA desaturase activities/alleles were positively correlated with skeletal fat (marbling) score, amount of monounsaturated fatty acids and conjugated linoleic acid content, but negatively with amount of saturated fatty acids. The inconsistent associations between human studies might be caused by using different sets of markers because we obeserved that most associated markers are located near the end of 3’UTR. We found that the proximity of the polyadenylation signal site is highly conserved among human, cattle and pig, indicating that the region might contain functional elements involved in posttranscriptional control. In conclusion, our cross species study provided solid evidence to support SCD1 gene as a critical player in skeletal muscle fat metabolism.

Last Modified: 10/22/2014