Sichuan Animal Science Academy, Chengdu, Sichuan, China.
Animal Breeding and Genetics key Laboratory of Sichuan Province, Chengdu, Sichuan, China.
PLoS One. 2018 Mar 21;13(3):e0193597. doi: 10.1371/journal.pone.0193597. eCollection 2018.
Tibetan chickens living at high altitudes show specific adaptations to high-altitude conditions, but the epigenetic modifications associated with these adaptations have not been characterized.
We investigated the genome-wide DNA methylation patterns in Tibetan chicken blood by using whole genome bisulfite sequencing. Generally, Tibetan chickens exhibited analogous methylation patterns to that of lowland chickens. A total of 3.92% of genomic cytosines were methylcytosines and 51.22% of cytosines in CG contexts were methylated, which was less than those in lowland chicken (55.69%). Moreover, the base adjacent to the methylcytosines of mCHGs in Tibetan chickens had a preference for T, which was different from that in lowland chickens. In Tibetan chickens, the methylation levels in the promoter were relatively low, while the gene body was also maintained in a hypomethylated state. DNA methylation levels in regions upstream of the transcription start site of genes were negatively correlated with the level of gene expression, and DNA methylation of gene body regions was also negatively related to gene expression.
We generated the genome-wide DNA methylation patterns in Tibetan chickens and our results will be helpful for future epigenetic studies related to adaptations to high-altitude conditions.
生活在高海拔地区的藏鸡表现出对高海拔环境的特定适应，但与这些适应相关的表观遗传修饰尚未得到表征。
我们通过全基因组亚硫酸氢盐测序研究了藏鸡血液的全基因组 DNA 甲基化模式。总体而言，藏鸡表现出与低地鸡相似的甲基化模式。总共有 3.92%的基因组胞嘧啶被甲基化胞嘧啶修饰，51.22%的 CG 环境中的胞嘧啶被甲基化，这低于低地鸡（55.69%）。此外，藏鸡中 mCHGs 甲基化胞嘧啶的碱基偏好 T，这与低地鸡不同。在藏鸡中，启动子的甲基化水平相对较低，而基因体也保持低甲基化状态。基因转录起始位点上游区域的 DNA 甲基化水平与基因表达水平呈负相关，基因体区域的 DNA 甲基化也与基因表达呈负相关。
我们生成了藏鸡的全基因组 DNA 甲基化模式，我们的结果将有助于未来与适应高海拔环境相关的表观遗传学研究。
