Genome-Wide Association Study for Fatty Acid Composition in American Angus Cattle

SIMPLE SUMMARY: Almost everybody depends on livestock for various reasons directly or indirectly. Consequently, improving livestock production means improving human life. Meat plays important role in human life, as it is good source of protein and energy. Meat composition depends on breed’s genetics and environmental factors. Fatty acids (FA) play important role in human diet and health. FA add flavor and taste to meat. Fatty acid composition of meat is a complex polygenic trait that is controlled by genetics and environmental factors. Therefore, the objective of the present study was to identify genomic regions associated with FA composition in American Angus. Thirty-six different genomic regions were identified associated with variation in at least one FA. The genomic regions associated with more than one FA and high genetic variance, harbor good candidate genes (e.g., FABP2, FASN, FADS2, FADS3 and SCD). The identified makers could be used to select for altered FA profile and help to increase the understanding of the genetic basis of FA composition. Furthermore, findings from the present study could help to devise effective breeding plans and selection strategies for the improvement of beef FA profile. ABSTRACT: Livestock is an important commodity playing a major role in the global economy. Red meat plays an important role in human life, as it is a good source of animal protein and energy. The fatty acid content of beef has been shown to impact the eating experience and nutritional value of beef. Therefore, this study aimed to identify genomic regions which can account for genetic variation in meat fatty acid content. Genotypes imputed to the Illumina BovineHD 770K BeadChip were used in this study. Thirty-six 1-Mb genomic regions with a posterior probability of inclusion (PPI) greater than 0.90 were identified to be associated with variation in the content of at least one fatty acid. The genomic regions (1Mb) which were associated with more than one fatty acid trait with high genetic variance and harbored good candidate genes were on Chromosome (Chr) 6 (fatty acid binding protein 2), Chr 19 (thyroid hormone receptor alpha, fatty acid synthase), Chr 26 (stearoyl-CoA desaturase), and Chr 29 (thyroid hormone responsive, fatty acid desaturase 2, and fatty acid desaturase 3). Further studies are required to identify the causal variants within the identified genomic regions. Findings from the present study will help to increase understanding of the variation in fatty acid content of beef and help to enhance selection for beef with improved fatty acid composition.