Modified nucleotides in mRNA are an essential addition to the standard genetic code of four nucleotides in animals, plants, and their viruses. The emerging field of epitranscriptomics examines nucleotide modifications in mRNA and their impact on gene expression. The low abundance of nucleotide modifications and technical limitations, however, have hampered systematic analysis of their occurrence and functions. Selective chemical and immunological identification of modified nucleotides has revealed global candidate topology maps for many modifications in mRNA, but further technical advances to increase confidence will be necessary. Single-molecule sequencing introduced by Oxford Nanopore now promises to overcome such limitations, and we summarize current progress with a particular focus on the bioinformatic challenges of this novel sequencing technology.

mRNA 中的修饰核苷酸是对动物、植物及其病毒中四种核苷酸的标准遗传密码的重要补充。表观转录组学这一新兴领域研究 mRNA 中的核苷酸修饰及其对基因表达的影响。然而，核苷酸修饰的低丰度和技术限制阻碍了对其发生和功能的系统分析。修饰核苷酸的选择性化学和免疫学鉴定已经揭示了 mRNA 中许多修饰的全局候选拓扑图，但需要进一步的技术进步来增加信心。牛津纳米孔推出的单分子测序现在有望克服这些限制，我们总结了当前的进展，特别关注这种新型测序技术的生物信息学挑战。