Santiago G G, Siqueira F, Cardoso F F, Regitano L C A, Ventura R, Sollero B P, Souza M D, Mokry F B, Ferreira A B R, Torres R A A
J Anim Sci. 2017 Aug;95(8):3381-3390. doi: 10.2527/jas.2017.1570.
The commercial value of the bovine carcass is determined by a set of traits, such as weight, yield, back fat thickness, and marbling; therefore, the genetic improvement of growth, meat, and carcass quality traits is an important tool to add value to the supply chain. Genomewide association studies (GWAS) enable the identification of loci that control phenotypic expression of quantitative traits (QTL). Therefore, the objective of this work was to perform a GWAS to identify genomic regions and genes associated with growth, carcass traits, and meat quality in Canchim beef cattle. These traits were yearling weight (YW), rib eye area (REA), back fat thickness (BFT), and marbling (MARB). To increase sample size and marker density, genotype imputation was performed, and only markers imputed with greater than 95% accuracy were used. Genomewide association study was performed using a Bayesian approach, by the Bayes B statistical method, incorporating genotypes and phenotypes from 614 animals from both the Canchim breed and the MA genetic group (offspring of Charolais bulls and one-half Canchim + one-half Zebu cows). This investigation identified 1 and 4 genomic regions explaining 0.23 and 7.35% of the genetic variance for REA and YW, respectively. These regions harbor a total of 19 genes, 7 of which were classified for biological functions by functional analysis. Significant associations were not observed for BFT and MARB. The identification of QTL that had been previously described in the literature reinforces associations found in this study.
牛胴体的商业价值由一系列性状决定，如体重、产肉量、背膘厚度和大理石花纹；因此，生长、肉质和胴体质量性状的遗传改良是增加供应链价值的重要工具。全基因组关联研究（GWAS）能够识别控制数量性状（QTL）表型表达的基因座。因此，本研究的目的是进行GWAS，以识别与坎辛牛肉牛生长、胴体性状和肉质相关的基因组区域和基因。这些性状包括周岁体重（YW）、眼肌面积（REA）、背膘厚度（BFT）和大理石花纹（MARB）。为了增加样本量和标记密度，进行了基因型填充，仅使用填充准确率大于95%的标记。采用贝叶斯方法，通过贝叶斯B统计方法进行全基因组关联研究，纳入了来自坎辛品种和MA遗传组（夏洛莱公牛与一半坎辛+一半瘤牛母牛的后代）的614头动物的基因型和表型。本研究确定了1个和4个基因组区域，分别解释了REA和YW遗传方差的0.23%和7.35%。这些区域共包含19个基因通过功能分析其中7个基因被归类为生物学功能。未观察到BFT和MARB的显著关联。文献中先前描述的QTL的鉴定加强了本研究中发现的关联。
