Masser Dustin R, Stanford David R, Freeman Willard M
Department of Physiology, University of Oklahoma College of Medicine.
Department of Physiology, University of Oklahoma College of Medicine; Department of Geriatric Medicine, University of Oklahoma College of Medicine;
J Vis Exp. 2015 Feb 24(96):52488. doi: 10.3791/52488.
The role of epigenetic processes in the control of gene expression has been known for a number of years. DNA methylation at cytosine residues is of particular interest for epigenetic studies as it has been demonstrated to be both a long lasting and a dynamic regulator of gene expression. Efforts to examine epigenetic changes in health and disease have been hindered by the lack of high-throughput, quantitatively accurate methods. With the advent and popularization of next-generation sequencing (NGS) technologies, these tools are now being applied to epigenomics in addition to existing genomic and transcriptomic methodologies. For epigenetic investigations of cytosine methylation where regions of interest, such as specific gene promoters or CpG islands, have been identified and there is a need to examine significant numbers of samples with high quantitative accuracy, we have developed a method called Bisulfite Amplicon Sequencing (BSAS). This method combines bisulfite conversion with targeted amplification of regions of interest, transposome-mediated library construction and benchtop NGS. BSAS offers a rapid and efficient method for analysis of up to 10 kb of targeted regions in up to 96 samples at a time that can be performed by most research groups with basic molecular biology skills. The results provide absolute quantitation of cytosine methylation with base specificity. BSAS can be applied to any genomic region from any DNA source. This method is useful for hypothesis testing studies of target regions of interest as well as confirmation of regions identified in genome-wide methylation analyses such as whole genome bisulfite sequencing, reduced representation bisulfite sequencing, and methylated DNA immunoprecipitation sequencing.
表观遗传过程在基因表达调控中的作用已为人所知多年。胞嘧啶残基处的DNA甲基化在表观遗传学研究中尤为引人关注,因为它已被证明是基因表达的一种持久且动态的调节因子。由于缺乏高通量、定量准确的方法,对健康和疾病中表观遗传变化的研究受到了阻碍。随着下一代测序(NGS)技术的出现和普及,除了现有的基因组和转录组方法外,这些工具现在也被应用于表观基因组学。对于已确定感兴趣区域(如特定基因启动子或CpG岛)的胞嘧啶甲基化的表观遗传学研究,并且需要以高定量准确性检测大量样本的情况,我们开发了一种称为亚硫酸氢盐扩增子测序(BSAS)的方法。该方法将亚硫酸氢盐转化与感兴趣区域的靶向扩增、转座体介导的文库构建和台式NGS相结合。BSAS提供了一种快速有效的方法,可同时分析多达96个样本中长达10 kb的靶向区域,大多数具备基本分子生物学技能的研究小组都可以进行。结果提供了具有碱基特异性的胞嘧啶甲基化的绝对定量。BSAS可应用于来自任何DNA来源的任何基因组区域。该方法对于感兴趣的靶区域的假设检验研究以及全基因组甲基化分析(如全基因组亚硫酸氢盐测序、简化代表性亚硫酸氢盐测序和甲基化DNA免疫沉淀测序)中鉴定区域的确认很有用。