Fig. 1
From: Emerging methylation-based approaches in microbiome engineering
Representative sequencing technologies for mapping DNA modifications. A Bisulfite sequencing begins with the treatment of genomic DNA (gDNA) with sodium bisulfite, a chemical that converts unmethylated cytosines (C) to uracils (U), while leaving methylated cytosines unchanged. PCR-amplified DNA fragments are then sequenced to determine the methylation status of cytosines across the genome. B Single-molecule real-time (SMRT) sequencing monitors the incorporation of fluorescently labeled nucleotides by a DNA polymerase in real time. Each nucleotide addition emits a fluorescent pulse as a signal. The DNA sequence is determined by the pattern of these signals, and interruptions in the pulse sequence indicate the presence of covalent modifications within the template DNA. C Nanopore sequencing utilizes the movement of a single DNA strand through a nanoscale pore (nanopore). As the DNA molecule passes through the pore, it causes disruptions in the electrical current, which are used to deduce the DNA sequence and detect DNA modifications such as 5mC, 4mC, and 6mA