Genetic association of delta-six fatty acid desaturase single nucleotide polymorphic molecular marker and muscle long chain omega-3 fatty acids in Australian lamb

To better understand the genetic variability in sheep muscle long-chain omega-3 polyunsaturated fatty acids and relationships with lipid synthesis and fat metabolism-related genes, this study investigated the association between polymorphisms of the fatty acid binding proteins (FABP1, FABP2) and Delta-6 desaturase (FADS2) gene clusters. Thirty-one single nucleotide polymorphisms (SNPs) were genotyped in Longissimus dorsi muscle samples from 362 crossbred prime lambs sired by five genetically divergent rams. Total intramuscular lipid long chain fatty acid levels were analysed using gas chromatography. Mixed model statistical analyses revealed that only FADS2 SNP was significantly associated (P<0.01) with intramuscular levels of eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids. The results suggest that this SNP is in linkage disequilibrium with functional lipid synthesis pathway associated with higher delta-six desaturase activity. For the first time, this study provides evidence for an association between genetic variants of FADS2 and omega-3 PUFA in sheep muscle. This SNP could potentially be a novel marker of choice for prime lamb producers to effectively select for enhanced muscle omega-3 fatty acid content in their breeding flock.