Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle

Background White spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein-Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein-Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date. Results Using imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2,973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immedia...研究背景 被毛白色斑点是包括牛类在内的多种驯养哺乳动物的标志性性状。该性状是荷斯坦-弗里生牛（Holstein-Friesian cattle）的典型特征，既往多项研究已在携带荷斯坦-弗里生牛血统的动物中，鉴定出对白色斑点性状具有显著效应的遗传位点。本研究旨在通过开展迄今为止规模最大的牛类该性状定位研究，深入解析白色斑点性状背后的遗传与分子调控机制。 研究结果 本研究利用填充后的全基因组序列数据，对2973头杂交品种奶牛与公牛开展全基因组关联分析（genome-wide association analysis）。研究在6号与22号染色体上检测到极显著的数量性状位点（quantitative trait loci, QTL），提示已被广泛证实的毛色相关基因KIT与MITF可能是该效应的调控靶点。上述结果与既往研究整体相符，但本研究同时在2号染色体上发现了一个全新的显著QTL位点，该信号紧邻...