Dietary n‐3 Fatty Acids Significantly Suppress Lipogenesis in Bovine Muscle and Adipose Tissue: A Functional Genomics Approach

AbstractChanges in fatty acid composition of longissimus muscle and subcutaneous adipose tissue of German Holstein bulls induced by a grass‐silage/n‐3 fatty acid based intervention diet versus a maize‐silage/n‐6 fatty acid based control diet were analyzed and related to shifts in lipogenic gene expression, protein expression, and enzyme activity patterns. Significantly higher amounts of n‐3 fatty acids and by mean factors of 2.2–2.5 decreased n‐6/n‐3 fatty acid ratios in both tissues were obtained upon n‐3 fatty acid intervention. In longissimus muscle, these changes of fatty acid profiles were associated with reduced SREBP1c (p = 0.02), ACC (p = 0.00), FAS (p = 0.10) and SCD (p = 0.03) gene expression, Δ6D (p = 0.03) and SCD (p = 0.03) protein expression as well as SCD enzyme activity (p = 0.03). In subcutaneous adipose tissue, significantly reduced ACC (p = 0.00) and FAS (p = 0.01) gene expression, SCD protein expression (p = 0.02) and SCD enzyme activity (p = 0.03) were detected upon n‐3 fatty acid intervention, although lower degrees of correlation between gene and corresponding gene products were obtained in relation to longissimus muscle. The study elucidates tissue‐specific functional genomic responses to dietary fatty acid manipulation in regard to fatty acid profile tailoring of animal tissues.