摘要
Residual energy intake (REI) on two successive diets (hay and maize based) and slaughter traits, including visceral organs, were phenotyped in 584 adult purebred Charolais cows. To investigate the relationships between these traits and their genetic determinism, we first estimated the genetic parameters, including correlations, using REML modeling under WOMBAT software. The animals were then genotyped on the BovineSNP50 SNPchip before being imputed to the 600K density and genome wide association study was performed with GCTA software. We found low heritability for REI (h2 = 0.12 in each of the diet phases). Although the phenotypic correlation between the two diet phases was moderate (0.36), the genetic correlation was high (0.83), indicating a common genetic determinism for feed efficiency regardless of the diet. Correlations between REI and slaughter traits were negative regarding muscle-related traits and positive for fat-related traits, indicating that efficient animals generally had a more muscular carcass. It was also seen that feed efficiency was genetically and phenotypically correlated with smaller organs when expressed as a proportion of their empty body weight. From the GWAS analysis, seven QTLs were found to be associated with a trait at the genome-wide level of significance and 18 others at the chromosome-wide level. One important QTL was detected in BTA 2, reflecting the essential effect of the myostatin gene on both carcass composition and relative organ weight. Three QTLs were detected for REI during the maize diet phase on BTA 13, 19, and 28, the latter being significant at the genome-wide level. The QTLs on BTA 19 mapped into the TANC2 gene and the QTLs on BTA 28 into the KIF1BP gene, which are both known to interact with the same protein (KIF1A). However, no obvious functional link between these genes and feed efficiency could be made. Among the other QTLs detected, one association on BTA 4 with liver proportion mapped to the candidate gene WASL, which has previously been shown to be differentially expressed in liver cells and linked to feed restriction or cancer development. No QTLs were found to be common between feed efficiency and any slaughter traits.
摘要译文
对584头成年纯种夏洛来牛奶牛的两种连续日粮（以干草和玉米为基础）的剩余能量摄入（REI）和包括内脏器官在内的屠宰性状进行了表型分析。为了研究这些性状与其遗传决定性之间的关系，我们首先在WOMBAT软件下使用REML建模来估算遗传参数，包括相关性。然后将动物在BovineSNP50 SNPchip上进行基因分型，然后将其估算为600K密度，并使用GCTA软件进行全基因组关联研究。我们发现REI的遗传力较低（每个饮食阶段的h 2 = 0.12）。尽管两个饮食阶段之间的表型相关性中等（0.36），但遗传相关性很高（0.83），这表明无论饮食如何，饲料效率的遗传决定因素都是常见的。 REI与屠宰性状之间的相关性在肌肉相关性状上为负，而在脂肪相关性状上则为正，表明有效的动物通常具有更多的肌肉car体。还可以看出，饲料效率与较小器官的遗传和表型相关，以其空体重的比例表示。通过GWAS分析，发现七个QTL与基因组的一个性状相关（全基因水平），另外18个在染色体的全基因组。在BTA 2中检测到一个重要的QTL，反映了myostatin基因对on体组成和相对器官重量的基本作用。在BTA 13、19和28的玉米饮食阶段中，检测到三个QTL的REI，后者在整个基因组水平上都很重要。 BTA 19上的QTL定位到TANC2基因中，而BTA 28上的QTL定位到KIF1BP基因中，这两个已知都与同一蛋白（KIF1A）相互作用。但是，这些基因与饲料效率之间没有明显的功能联系。在检测到的其他QTL中，BTA 4上的一个与肝脏比例相关的关联映射到候选基因WASL，该关联先前已显示在肝细胞中差异表达，并与饲料限制或癌症发展有关。在饲料效率和任何屠宰性状之间均未发现常见的QTL。
Pauline Martin[1];Sébastien Taussat[1];Aurélie Vinet[1];Daniel Krauss[2];David Maupetit[2];Gilles Renand[1]. Genetic parameters and genome-wide association study regarding feed efficiency and slaughter traits in Charolais cows[J]. Journal of Animal Science, 2019,97(9): 3684-3698