Body conformation, including withers height, is a major selection criterion in horse breeding and is associated with other important traits, such as health and performance. However, little is known about the genomic background of equine conformation. Therefore, the aim of this study was to use imputed sequence-level genotypes from up to 4891 German Warmblood horses to identify genomic regions associated with withers height and linear conformation traits. Furthermore, the traits were genetically characterised and putative causal variants for withers height were detected. A genome-wide association study (GWAS) for withers height confirmed the presence of a previously known quantitative trait locus (QTL) on Equus caballus (ECA) chromosome 3 close to the LCORL/NCAPG locus, which explained 16% of the phenotypic variance for withers height. An additional significant association signal was detected on ECA1. Further investigations of the region on ECA3 identified a few promising candidate causal variants for withers height, including a nonsense mutation in the coding sequence of the LCORL gene. The estimated heritability for withers height was 0.53 and ranged from 0 to 0.34 for the conformation traits. GWAS identified significantly associated variants for more than half of the investigated conformation traits, among which 13 showed a peak on ECA3 in the same region as withers height. Genetic parameter estimation revealed high genetic correlations between these traits and withers height for the QTL on ECA3. The use of imputed sequence-level genotypes from a large study cohort led to the discovery of novel QTL associated with conformation traits in German Warmblood horses. The results indicate the high relevance of the QTL on ECA3 for various conformation traits, including withers height, and contribute to deciphering causal mutations for body size in horses.

中文翻译：

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使用估算的序列水平基因型对德国温血马马肩隆高度和线性构象特征进行基因组分析


身体构造，包括马肩隆高度，是马匹育种的主要选择标准，并与其他重要特征（例如健康和性能）相关。然而，人们对马构象的基因组背景知之甚少。因此，本研究的目的是使用来自多达 4891 匹德国温血马的推算序列水平基因型来识别与马肩隆高度和线性构象性状相关的基因组区域。此外，对这些性状进行了遗传表征，并检测到了马肩隆高度的推定因果变异。一项针对马肩隆高度的全基因组关联研究 (GWAS) 证实，马驹 (ECA) 3 号染色体上靠近 LCORL/NCAPG 基因座的位置存在先前已知的数量性状基因座 (QTL)，这解释了马肩隆 16% 的表型变异。马肩隆高度。在 ECA1 上检测到一个额外的显着关联信号。对 ECA3 区域的进一步研究发现了一些有希望的马肩隆高度候选因果变异，包括 LCORL 基因编码序列中的无义突变。马肩隆高度的估计遗传力为 0.53，构象性状的遗传力范围为 0 至 0.34。 GWAS 鉴定出一半以上所研究的构象性状的显着相关变异，其中 13 个在与马肩隆高度相同的区域显示 ECA3 峰值。遗传参数估计揭示了这些性状与 ECA3 上 QTL 的凋萎高度之间的高度遗传相关性。使用来自大型研究队列的推算序列水平基因型发现了与德国温血马构象性状相关的新 QTL。 结果表明，ECA3 上的 QTL 与各种构象性状（包括马肩隆高度）高度相关，并有助于破译马体型的因果突变。