Recent technical advances in the study of nucleic acid modifications.

Enzyme-mediated chemical modifications of nucleic acids are indispensable regulators of gene expression. Our understanding of the biochemistry and biological significance of these modifications has largely been driven by an ever-evolving landscape of technologies that enable accurate detection, mapping, and manipulation of these marks. Here we provide a summary of recent technical advances in the study of nucleic acid modifications with a focus on techniques that allow accurate detection and mapping of these modifications. For each modification discussed (N6-methyladenosine, 5-methylcytidine, inosine, pseudouridine, and N4-acetylcytidine), we begin by introducing the "gold standard" technique for its mapping and detection, followed by a discussion of techniques developed to address any shortcomings of the gold standard. By highlighting the commonalities and differences of these techniques, we hope to provide a perspective on the current state of the field and to lay out a guideline for development of future technologies.