Identification of SNPs in the FASN gene and their effect on fatty acid milk composition in Holstein cattle

FASN is a multifunctional enzyme that catalyzes de novo biosynthesis of long-chain saturated fatty acid, and alteration of this enzyme may affect economic traits including fatty acid composition. Sequencing the coding sequence (CDS) of the FASN gene has so far been done only partially for dairy cattle. In this study, the CDS of the FASN gene of eight Holstein cattle was sequenced to detect nucleotide polymorphisms. We could identify 13 single nucleotide polymorphisms (SNPs) of which five were non-synonymous mutations (H1390Y, I1856L, T1950A, W1955R and T2264A). The association between these SNPs and economic traits was analyzed using 198 Holstein dams. Genotypes of H1390Y corresponded to those of the I1856L in the group, suggesting these SNPs were linked. Furthermore, the T1950A was suggestively linked with the W1955R. The association study revealed that T1950A/W1955R had an effect on milk fat content and the C14 Index. This will help to understand the complex association between the FASN gene and economic traits.