School of Biological Sciences, University of Auckland, Auckland, New Zealand.
Livestock Improvement Corporation, Hamilton, New Zealand.
Sci Rep. 2017 Mar 21;7:44793. doi: 10.1038/srep44793.
A major pleiotropic quantitative trait locus (QTL) located at ~25 Mbp on bovine chromosome 14 affects a myriad of growth and developmental traits in Bos taurus and indicus breeds. These QTL have been attributed to two functional variants in the bidirectional promoter of PLAG1 and CHCHD7. Although PLAG1 is a good candidate for mediating these effects, its role remains uncertain given that these variants are also associated with expression of five additional genes at the broader locus. In the current study, we conducted expression QTL (eQTL) mapping of this region using a large, high depth mammary RNAseq dataset representing 375 lactating cows. Here we show that of the seven previously implicated genes, only PLAG1 and LYN are differentially expressed by QTL genotype, and only PLAG1 bears the same association signature of the growth and body weight QTLs. For the first time, we also report significant association of PLAG1 genotype with milk production traits, including milk fat, volume, and protein yield. Collectively, these data strongly suggest PLAG1 as the causative gene underlying this diverse range of traits, and demonstrate new effects for the locus on lactation phenotypes.
一个主要的多效数量性状基因座（QTL）位于牛 14 号染色体上约 25Mb 处，影响牛属和印度牛品种的许多生长和发育性状。这些 QTL 归因于 PLAG1 和 CHCHD7 双向启动子中的两个功能变体。尽管 PLAG1 是介导这些效应的良好候选基因，但由于这些变体也与更广泛基因座中另外五个基因的表达相关，因此其作用仍不确定。在本研究中，我们使用代表 375 头泌乳奶牛的大型、高深度乳腺 RNAseq 数据集进行了该区域的表达数量性状（eQTL）图谱绘制。在这里，我们表明，在之前涉及的七个基因中，只有 PLAG1 和 LYN 的基因表达受 QTL 基因型的差异表达，并且只有 PLAG1 具有与生长和体重 QTL 相同的关联特征。我们首次报告了 PLAG1 基因型与产奶性状（包括乳脂、体积和蛋白质产量）的显著关联。综上所述，这些数据强烈表明 PLAG1 是该多种性状的致病基因，并证明了该基因座对泌乳表型的新影响。
