Association of a polymorphism in the 3' untranslated region of the <i>OLR1</i> gene with milk fat and protein in dairy cows

Abstract

Oxidized low density lipoprotein receptor 1 (OLR1) is the major cell surface receptor for oxidized low density lipoprotein (Ox-LDL). The role of OLR1 in lipid metabolism and the existence of milk-related QTL in the vicinity of the OLR1 gene have prompted the investigation of OLR1 as a candidate gene influencing milk production traits. The present study explored the association of a single nucleotide polymorphism (SNP) in the 3' untranslated region of the OLR1 gene (OLR1 g.8232 C>A ) with milk-related traits in 408 Iranian Holstein cows. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was performed for genotyping the animals. Animals with genotype CC had the highest and animals with genotype AA had the lowest fat percentage while genotype AC was intermediate (P<0.05). Cows carrying genotype CC showed more milk fat yield compared to the genotypes AC (P<0.1) and AA (P<0.01). Cows of genotypes CC and AC had a higher milk protein percentage than those of genotype AA (P<0.01). Regarding the association revealed, the SNP has the potential to be considered as a marker in marker-assisted selection.

Polymorphism in the OLR1 gene and functional traits of dairy cattle

“…a higher frequency of the C allele was noted for Nelore beef cattle, divided into three selection groups, where its frequency ranged from 0.79 to 0.89 (FONSECA et al, 2015); for Bos indicus 0.83 and 0.95 for Brown Swiss (KHATIB et al, 2006); also for South Anatolian Red and East Anatolian Red 0.89 and 0.91, respectively (ATES et al, 2014). as for other studies, the researchers noted a lower frequency of the C allele than that observed in their own research: Holstein cattle 0.54 (KHATIB et al, 2006), Holstein-Friesian Black and White strain 0.57 (KOMISAREK and DORYNEK, 2009), Czech Fleckvieh 0.51 (RYCHTAROVA et al, 2014), Iranian Holstein 0.48, 0.47 and 0.53 (SOLTANI-GHOMBAVANI et al, 2013;REZAEI et al, 2016;MASHHADI et al, 2014), and Iranian Simmental 0.62 (REZAEI et al, 2016). The divergence in the distribution of particular genotypes may result from the different breeds for which individual research was conducted, as well as from the research of other authors involving individual, not very large herds of cattle.…”

“…a8232C polymorphism, until now, has mainly been studied in relation to the milk production traits of cattle. Numerous authors have shown a relationship between this polymorphism and mainly the fat yield and fat content in milk (KHATIB et al, 2006;KHATIB et al, 2007;KOMISAREK and DORYNEK, 2009;SOLTANI-GHOMBAVANI et al, 2013). FONSeCa et al, (2015) conducted research on the traits of Nelore beef cattle and found significant correlations (P≤0.05) between genotypes and the thickness of rump fat thickness and weaning weight.…”

A novel p.K116Q SNP in the OLR1 gene and its relation to fecundity in Awassi ewes

“…Besides, the SNP in the bovine OLR1 gene (c. 495 T> C) affects carcass traits, fat accumulation, and growth in Angus, Charolais, and hybrid cattle [11]. The OLR gene is investigated in another study conducted on Dutch Holsteins/Friesians; the results indicated that OLR g.8232C>A signi cantly affected (P < 0.05) the fat content of milk [12]. A genetic variant in buffalo OLR1 at position 8,232 in the 3′-UTR has been affected by fat content and yield in the Mehsana breed [13].…”