The effect of polymorphism in the FADS2 gene on the fatty acid composition of bovine milk

Polyunsaturated fatty acids (PUFAs) play a role in a wide variety of physiological processes. They are produced by a series of desaturation and elongation reactions. [Formula: see text]-6-desaturase is a membrane-bound enzyme that catalyzes the conversion of [Formula: see text]-linolenic acid (C18:3 [Formula: see text]-3) and linoleic acid (C18:2 [Formula: see text]-6) to stearidonic acid (18:4 [Formula: see text]-3) and [Formula: see text]-linolenic acid (18:3 [Formula: see text]-6). It is encoded by the FADS2 gene located on bovine chromosome 29. The aim of this study was to identify a single nucleotide polymorphism in the FADS2 gene and to determine possible associations with milk fatty acid composition in two breeds of dairy cattle, i.e., Jersey and Polish Holstein-Friesian. Direct DNA sequencing revealed the presence of an A-to-G substitution in intron 3 of the FADS2 gene (rs209202414). Both populations were genotyped with an appropriate PCR-RFLP assay. The following genotype distributions were observed: for Jerseys, AA [Formula: see text] 0.24, AG [Formula: see text] 0.63, and GG [Formula: see text] 0.13; for Polish Holstein-Friesians, AA [Formula: see text] 0.17, AG [Formula: see text] 0.40, and GG [Formula: see text] 0.43. In Jerseys, statistically significant relationships were found between the FASD2 genotypes and the following milk fatty acids: lauric ([Formula: see text]), behenic ([Formula: see text]), lignoceric ([Formula: see text]), oleic ([Formula: see text]), eicosatrienoic ([Formula: see text]), and docosadienoic ([Formula: see text]). In Polish Holstein-Friesian cows, significant associations were observed for erucic ([Formula: see text]) and docosahexaenoic ([Formula: see text]) acids. The study indicated the A-to-G substitution (rs209202414) in the bovine FADS2 gene as a potential genetic marker for fatty acid composition in cattle milk.