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

Abstract

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. 1-6-desaturase is a membrane-bound enzyme that catalyzes the conversion of -linolenic acid (C18:3n-3) and linoleic acid (C18:2n-6) to stearidonic acid (18:4n- 3) and -linolenic acid (18:3n-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, AAD0.24, AGD0.63, and GGD0.13; for Polish Holstein- Friesians, AAD0.17, AGD0.40, and GGD0.43. In Jerseys, statistically significant relationships were found between the FASD2 genotypes and the following milk fatty acids: lauric (P D 0:0486), behenic (P D 0:0199), lignoceric (P D 0:0209), oleic (P D 0:0386), eicosatrienoic (P D 0:0113), and docosadienoic (P D 0:0181). In Polish Holstein-Friesian cows, significant associations were observed for erucic (P D 0:0460) and docosahexaenoic (P D 0:0469) 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.