Influence of DGAT1 K232A Polymorphism on Milk Fat Percentage and Fatty Acid Profiles in Romanian Holstein Cattle

Abstract

Milk and dairy products are considered the main sources of saturated fatty acids, which are a valuable source of nutrients in the human diet. Fat composition can be adjusted through guided nutrition of dairy animals but also through selective breeding. Recently, a dinucleotide substitution located in the exon 8 of the gene coding for acyl CoA: diacylglycerol acyltransferase 1 (DGAT1), that alters the amino acid sequence from a lysine to an alanine (p.Lys232Ala) in the mature protein, was shown to have a strong effect on milk fat content in some cattle breeds. Therefore, the objectives of this work were to study the occurrence of the DGAT1 p.Lys232Ala polymorphism in Romanian Holstein cattle and Romanian Buffalo breeds and to further investigate its possible influence on fat percentage and fatty acid profiles. The results obtained in this study show that in Romanian Holstein cattle the K allele is associated with increased fat percentage and higher levels of C16:0 and C18:0 fatty acids. The ratio of saturated fatty acids versus unsaturated fatty acids (SFA/UFA) was also higher in KK homozygous individuals, whereas the fractions of C14:0, unsaturated C18 decreased. The DGAT1 p.Lys232Ala polymorphism revealed a high genetic variance for fat percentage, unsaturated C18, C16:0, and SFA/UFA. Although the effect of this polymorphism was not so evident for short chain fatty acids such as C4:0-C8:0, it was significant for C14:0 fatty acids. We concluded that selective breeding of carriers of the A allele in Romanian Holsteins can contribute to improvement in unsaturated fatty acids content of milk. However, in buffalo, the lack of the A allele makes selection inapplicable because only the K allele, associated with higher saturated fatty acids contents in milk, was identified.

Genome-wide identification of Diacylglycerol Acyltransferases (DGAT) family genes influencing Milk production in Buffalo

“…The missense mutation K232A in DGAT1 showed to have significant effects on milk traits in cattle, which the A allele was associated with increased milk yield, whereas the K allele with increased fat and protein concentrations [8,9]. Moreover, the DGAT1 K232A was also contributed to influence the fatty acids contents of milk in both cattle and buffalo [10]. Polymorphisms of the DGAT1 were found to be fixed on allele K at K232A locus in some buffalo breeds, which were considered to be the primary responsibility for the high milk fat in buffalo [4,11,12].…”

Effects of Single Nucleotide Polymorphisms in the SLC27A3 Gene on the Nutritional Value of Sheep Milk

“…The composition of milk fatty acids depends on breed, lactation stage, environment, and animals' diet [10,27]. Moreover, fatty acid profile is affected by genetic factors, such as polymorphism of BLG, DGAT1, and Stearoyl-CoA Desaturase 1 (SCD1) genes [28][29][30].…”

Polymorphisms in the DGAT1 gene in buffaloes (Bubalus bubalis) in the Amazon

“…Another study showed that minisatellite markers in DGAT1 are associated with milk constituents in buffaloes (Cardoso et al, 2015). Tăbăran et al (2015) reported the influence of polymorphisms in DGAT1 on the percentage and profile of milk fat in Romanian Holstein cattle; therefore, they should be used in marker-assisted selection (Hill et al, 2016). Lacorte et al (2006) used polymerase chain reaction (PCR)-restriction fragment length polymorphism to reveal that SNPs in DGAT1 exhibited a high frequency of the A allele in Holstein and Gyr x Holstein F 1 cattle.…”