Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117543, Singapore.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Dev Cell. 2018 May 7;45(3):406-416.e3. doi: 10.1016/j.devcel.2018.03.012. Epub 2018 Apr 12.
DNA methylation on N-adenine (6mA) has recently been found to be a potentially epigenetic mark in several unicellular and multicellular eukaryotes. However, its distribution patterns and potential functions in land plants, which are primary producers for most ecosystems, remain largely unknown. Here we report global profiling of 6mA sites at single-nucleotide resolution in the genome of Arabidopsis thaliana at different developmental stages using single-molecule real-time sequencing. 6mA sites are widely distributed across the Arabidopsis genome and enriched over the pericentromeric heterochromatin regions. 6mA occurs more frequently in gene bodies than intergenic regions. Analysis of 6mA methylomes and RNA sequencing data demonstrates that 6mA frequency positively correlates with the gene expression level and the transition from vegetative to reproductive growth in Arabidopsis. Our results uncover 6mA as a DNA mark associated with actively expressed genes in Arabidopsis, suggesting that 6mA serves as a hitherto unknown epigenetic mark in land plants.
最近在一些单细胞和多细胞真核生物中发现，N-腺嘌呤（6mA）上的 DNA 甲基化可能是一种表观遗传标记。然而，在大多数生态系统的主要生产者——陆地植物中，其分布模式和潜在功能在很大程度上仍不清楚。在这里，我们使用单分子实时测序，在不同发育阶段的拟南芥基因组中以单核苷酸分辨率报告了 6mA 位点的全球图谱。6mA 位点广泛分布于拟南芥基因组中，并富集在着丝粒周围异染色质区域。6mA 在基因体中比基因间区域更频繁出现。对 6mA 甲基组和 RNA 测序数据的分析表明，6mA 的频率与基因表达水平以及拟南芥从营养生长向生殖生长的转变呈正相关。我们的结果揭示了 6mA 作为与拟南芥中活跃表达基因相关的 DNA 标记，表明 6mA 是陆地植物中一种未知的表观遗传标记。
