Effect of Breed on Fatty Acid Composition and Lipogenic Enzyme Abundance in the Subcutaneous Adipose Tissue of Pigs

摘要

This study investigated the role of lipogenic enzyme expression in breed-specific fat deposition in pigs. Objectives: (ⅰ) determine effect of breed on the relative abundance of the key lipogenic enzymes stearoyl-CoA desaturase (SCD), delta-6 desaturase (A6D), and fatty acid synthase (FAS) in pig subcutaneous adipose tissue. (ⅱ) Investigate breed-specific relationships between lipogenic enzyme abundance and fatty acid composition. Large White x Pietrain, Pietrain, and Duroc x Pietrain pigs were used. Expression of SCD, Δ6D, and FAS was analyzed by Western blotting. Fatty acid composition was determined by gas chromatography. FAS protein in Large White x Pietrain pigs was similar to the Pietrain breed, but was significantly higher than Duroc x Pietrain. A positive relationship was found between FAS abundance and the saturated fatty acids (SFAs), for Large White x Pietrain pigs, but not for the other breeds. Δ6D was significantly higher in Large White × Pietrain compared with Duroc × Pietrain and Pietrain. This was accompanied by significantly higher total n-3 poly-unsaturated fatty acids (PUFAs) in the Large White × Pietrain when compared to the other breeds. Conclusions: (ⅰ) increased subcutaneous adipose tissue SFA content in Large White x Pietrain pigs (but not Pietrain and Duroc × Pietrain) is related to increased abundance of FAS protein; (ⅱ) high n-3 PUFA content in Large White × Pietrain pigs is related to activation of Δ6D protein synthesis; (ⅲ) SCD and Δ6D abundance does not contribute to between-breed differences in MUFA and n-6 PUFA content of pig subcutaneous adipose tissue.