Sasaki Shinji, Ibi Takayuki, Kojima Takatoshi, Sugimoto Yoshikazu
National Livestock Breeding Center, Odakura, Nishigo, Fukushima, 961-8511, Japan.
Graduate School of Environmental and Life Science, Okayama University, Tsushima-naka, Okayama, 700-8530, Japan.
Anim Genet. 2016 Feb;47(1):102-5. doi: 10.1111/age.12360. Epub 2015 Sep 16.
Days open (DO), which is the interval from calving to conception, is an important trait related to reproductive performance in cattle. To identify quantitative trait loci for DO in Japanese Black cattle, we conducted a genome-wide association study with 33,303 single nucleotide polymorphisms (SNPs) using 459 animals with extreme DO values selected from a larger group of 15,488 animals. We identified a SNP on bovine chromosome 2 (BTA2) that was associated with DO. After imputation using phased haplotype data inferred from 586 812 SNPs of 1041 Japanese Black cattle, six SNPs associated with DO were located in an 8.5-kb region of high linkage disequilibrium on BTA2. These SNPs were located on the telomeric side at a distance of 177 kb from the parathyroid hormone 2 receptor (PTH2R) gene. The association was replicated in a sample of 1778 animals. In the replicated population, the frequency of the reduced-DO allele (Q) was 0.63, and it accounted for 1.72% of the total genetic variance. The effect of a Q-to-q allele substitution on DO was a decrease of 3.74 days. The results suggest that the Q allele could serve as a marker in Japanese Black cattle to select animals with superior DO performance.
产犊至受孕间隔天数（DO）是与牛繁殖性能相关的一个重要性状。为了鉴定日本黑牛DO的数量性状基因座，我们使用从15488头较大群体中挑选出的459头具有极端DO值的动物，对33303个单核苷酸多态性（SNP）进行了全基因组关联研究。我们在牛2号染色体（BTA2）上鉴定出一个与DO相关的SNP。利用从1041头日本黑牛的586812个SNP推断出的分阶段单倍型数据进行插补后，6个与DO相关的SNP位于BTA2上一个8.5kb的高连锁不平衡区域。这些SNP位于端粒侧，距离甲状旁腺激素2受体（PTH2R）基因177kb处。该关联在1778头动物的样本中得到了重复验证。在重复验证群体中，低DO等位基因（Q）的频率为0.63，它占总遗传方差的1.72%。Q-to-q等位基因替换对DO的影响是减少3.74天。结果表明，Q等位基因可作为日本黑牛中选择具有优异DO性能动物的一个标记。
