Polymorphisms in lipogenic genes and milk fatty acid composition in Holstein dairy cattle

Abstract

Changing bovine milk fatty acid (FA) composition through selection can decrease saturated FA (SFA) consumption, improve human health and provide a means for manipulating processing properties of milk. Our study determined associations between milk FA composition and genes from triacylglycerol (TAG) biosynthesis pathway. The GC dinucleotide allele of diacylglycerol O-acyltransferase 1:g.10433-10434AA >GC was associated with lower palmitic acid (16:0) concentration but higher oleic (18:1 cis-9), linoleic (18:2 cis-9, cis-12) acid concentrations, and elongation index. Accordingly, the GC dinucleotide allele was associated with lower milk fat percentage and SFA concentrations but higher monounsaturated FA and polyunsaturated FA (PUFA) concentrations. The glycerol-3-phosphate acyltransferase, mitochondrial haplotypes were associated with higher myristoleic acid (14:1 cis-9) concentration and C14 desaturation index. The 1-acylglycerol-3-phosphate acyltransferase 1 haplotypes were associated with higher PUFA and linoleic acid concentrations. The results of this study provide information for developing genetic tools to modify milk FA composition in dairy cattle.

Effects of candidate gene polymorphisms on the detailed fatty acids profile determined by gas chromatography in bovine milk

“…Results obtained in studies on human and animal models identified and characterized C16:1 cis-9 as a novel lipokine or lipid hormone (German, 2011). Nafikov et al (2014) did not observe any significant association between LPIN1 haplotypes and the milk fatty acid composition in Holstein cows.…”

“…Several prior studies have taken the approach of performing association analyses between candidate genes and the milk fatty acid profile, but these studies considered relatively few genes and fatty acid traits (e.g., Rincon et al, 2012;Marchitelli et al, 2013;Nafikov et al, 2014). Moreover, to our knowledge, only one previ-ous study reported association analyses with the milk fatty acid profile of the Brown Swiss breed (Strillacci et al, 2014).…”

“…The lipin 1 (LPIN1) gene on BTA11 encodes the enzyme that cleaves the P group of phosphatidic acid during its conversion to diacylglycerol. The LPIN1 gene is the major isoform expressed in the bovine mammary gland, and its expression increased more than 3-fold during the first phase of lactation (Bionaz and Loor, 2008;Nafikov et al, 2014). It is known to be directly involved in milk fat synthesis and in regulating the transcription of other genes involved in milk fat synthesis (Bionaz and Loor, 2008).…”

“…Moreover, candidate gene studies have shown that SNP in the genes encoding stearoyl-CoA desaturase (SCD), diacylglycerol o-acyltransferase 1 (DGAT1), and sterol regulatory element binding protein-1 (SREBP1) clearly influence the milk fat composition and explain part of the genetic variation of milk fat unsaturation indices seen in Holsteins (Schennink et al, 2007(Schennink et al, , 2008Rincon et al, 2012) and Brown Swiss cows (Mele et al, 2007;Conte et al, 2010). Single nucleotide polymorphisms located in other genes involved in lipid biosynthesis have also been shown to affect the milk fatty acid compositions of different bovine breeds (Matsumoto et al, 2012;Marchitelli et al, 2013;Nafikov et al, 2014). Genomewide studies in Holstein cows have allowed researchers to detect QTL harboring candidate polymorphic genes that are involved in fat synthesis or known to affect fat yield or content, and significantly associated with fatty acids (~20 fatty acid traits were considered) (e.g., Stoop et al, 2009;Bouwman et al, 2011).…”

Variation in the yak lipin-1 gene and its association with milk traits

“…This supports the contention that LPIN1 is having an effect on milk traits in two bovine species, and is consistent with yaks and cattle being closely related to each other. However, this does need to be balanced against the findings of Nafikov et al (2014), who found no association between a SNP in the 5 ′ UTR of Holstein cattle and milk traits.…”