Profiling DNA Methylation Using Bisulfite Sequencing (BS-Seq).

DNA cytosine methylation is one of the most abundant epigenetic marks found in the plant nuclear genome. Bisulfite sequencing (BS-Seq) is the method of choice for profiling DNA cytosine methylation genome-wide at a single nucleotide resolution. The basis of this technique is that the unmethylated cytosine can be deaminated to uracil by sodium bisulfite, while the methylated cytosine is resistant to the treatment. By deep sequencing of the bisulfite converted genomic DNA, the methylation level of each mappable cytosine position in the genome could be measured. In this chapter, we present a detailed 2-day protocol for performing a BS-Seq experiment and a simple bioinformatic workflow for wet lab biologists to visualize the methylation data.