DIRECT VISUALIZATION OF SITE-SPECIFIC AND STRAND-SPECIFIC DNA METHYLATION PATTERNS IN AUTOMATED DNA-SEQUENCING DATA

We report here a simple method of directly visualizing in automated DN A sequencing chromatograms DNA methylations of different types includi ng cytosine methylations in Hpall and dcm sites as well as adenine met hylations in dam sites. This is made possible by the observation that the extent of incorporation of fluorescently labeled dideoxynucleotide s is influenced by the methylated bases in template DNA. This simple a pproach involves routine automated DNA sequencing without any prior tr eatment of DNA specific for detecting DNA methylation.