Genomic regions associated with bovine milk fatty acids in both summer and winter milk samples

Abstract

BackgroundIn this study we perform a genome-wide association study (GWAS) for bovine milk fatty acids from summer milk samples. This study replicates a previous study where we performed a GWAS for bovine milk fatty acids based on winter milk samples from the same population. Fatty acids from summer and winter milk are genetically similar traits and we therefore compare the regions detected in summer milk to the regions previously detected in winter milk GWAS to discover regions that explain genetic variation in both summer and winter milk.ResultsThe GWAS of summer milk samples resulted in 51 regions associated with one or more milk fatty acids. Results are in agreement with most associations that were previously detected in a GWAS of fatty acids from winter milk samples, including eight ‘new’ regions that were not considered in the individual studies. The high correlation between the –log10(P-values) and effects of SNPs that were found significant in both GWAS imply that the effects of the SNPs were similar on winter and summer milk fatty acids.ConclusionsThe GWAS of fatty acids based on summer milk samples was in agreement with most of the associations detected in the GWAS of fatty acids based on winter milk samples. Associations that were in agreement between both GWAS are more likely to be involved in fatty acid synthesis compared to regions detected in only one GWAS and are therefore worthwhile to pursue in fine-mapping studies.

A post-GWAS confirming theSCDgene associated with milk medium- and long-chain unsaturated fatty acids in Chinese Holstein population

“…Bouwman et al . () reported that the 293V allele at the p.Ala293Val locus was positively associated with C16 index and CLA compared with the 293A allele in both summer and winter milk. In this study, we also identified a variation of p.Ala293Val, namely g.10329C>T, and found it was significantly associated with C14:0, C14:1, C16:1, C18:2n6c, CLA, C14 index and C16 index.…”

“…) and genome‐wide association studies (GWASs) (Bouwman et al . , ; Buitenhuis et al . ) have been implemented to detect genes or QTL for milk fatty acid traits, and a few prominent findings involving the stearoyl‐CoA desaturase (delta‐9‐desaturase) gene ( SCD ) were obtained.…”

Combining multi-population datasets for joint genome-wide association and meta-analyses: The case of bovine milk fat composition traits

“…The regions detected on BTA 14 (region 14a) and BTA 26 are known to contain the DGAT1 and SCD1 genes, respectively. Studies have frequently reported significant associations between several milk FA traits and the DGAT1 (Schennink et al, 2008; and SCD1 (Schennink et al, 2008;Bouwman et al, 2012;Carvajal et al, 2016) genes. Detections in the DGAT1 region were similar for the joint GWAS and the meta-analysis, with significant associations established for 14 FA traits.…”

Associação aditiva, dominante e epistática de SNPs à produção e composição do leite em vacas da raça Holandesa

“…O leite bovino é composto por aproximadamente 87% de água e 13% de elementos sólidos (MOURÃO et al, 2012), sendo considerado um importante alimento principalmente para lactentes (MAIJALA, 2000). O consumo médio de leite, vem crescendo nos últimos anos no Brasil, atingindo 124,6 kg em 2007(FAO, 2012 BOUWMAN et al, 2011BOUWMAN et al, , 2012GLANTZ et al, 2012) MENSINK et al, 2003;SHINGFIELD et al, 2008;GIBSON, 2011), aumento do risco de aterosclerose, obesidade e doenças coronárias (HU et al, 1999;HAUG;HOSTMARK;HARSTAD, 2007). No entanto, o ácido esteárico (C18:0) têm revelado pouco ou nenhum efeito sobre as concentrações de colesterol total e LDL, assim como outros ácidos graxos de cadeia curta e média pertencentes a esta categoria (MENSINK et al, 2003;SHINGFIELD et al, 2008;GIBSON, 2011…”

“…As principais vantagens que tornaram os SNPs tão estudados e utilizados são a sua maior frequência, ampla distribuição no genoma, e baixo custo de genotipagem em massa. BTA11) Bouwman et al (2011Bouwman et al ( , 2012. encontraram regiões associadas ao perfil de ácidos graxos no leite no BTA14, BTA19 e BTA26, que são regiões conhecidas por estar situado importantes genes como o DGAT1, FASN e SCD1, respectivamente Aswell et al (2004),Meredith et al (2010Meredith et al ( , 2012.…”