Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, NSW, Australia.
St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
Methods Mol Biol. 2021;2272:163-178. doi: 10.1007/978-1-0716-1294-1_9.
5-Methylcytosine (5mC) is one of the most abundant and well-studied chemical DNA modifications of vertebrate genomes. 5mC plays an essential role in genome regulation including: silencing of retroelements, X chromosome inactivation, and heterochromatin stability. Furthermore, 5mC shapes the activity of cis-regulatory elements crucial for cell fate determination. TET enzymes can oxidize 5mC to form 5-hydroxymethylcytosine (5hmC), thereby adding an additional layer of complexity to the DNA methylation landscape dynamics. The advent of techniques enabling genome-wide 5hmC profiling provided critical insights into its genomic distribution, scope, and function. These methods include immunoprecipitation, chemical labeling and capture-based approaches, as well as single-nucleotide 5hmC profiling techniques such as TET-assisted bisulfite sequencing (TAB-seq) and APOBEC-coupled epigenetic sequencing (ACE-seq). Here we provide a detailed protocol for computational analysis required for the genomic alignment of TAB-seq and ACE-seq data, 5hmC calling, and statistical analysis.
5- 甲基胞嘧啶(5mC)是脊椎动物基因组中最丰富和研究最深入的化学 DNA 修饰之一。5mC 在基因组调控中发挥着重要作用,包括:逆转录元件的沉默、X 染色体失活和异染色质稳定性。此外,5mC 塑造了对细胞命运决定至关重要的顺式调控元件的活性。TET 酶可以将 5mC 氧化为 5-羟甲基胞嘧啶(5hmC),从而为 DNA 甲基化景观动力学增加了一个额外的复杂性层次。能够进行全基因组 5hmC 谱分析的技术的出现,为其基因组分布、范围和功能提供了关键的见解。这些方法包括免疫沉淀、化学标记和基于捕获的方法,以及单核苷酸 5hmC 谱分析技术,如 TET 辅助亚硫酸氢盐测序(TAB-seq)和 APOBEC 偶联的表观遗传测序(ACE-seq)。在这里,我们提供了一个详细的协议,用于 TAB-seq 和 ACE-seq 数据的基因组比对、5hmC 调用和统计分析所需的计算分析。