|DNA molecule that is methylated on both strands on the|
by Christoph Bock
A recent paper entitled 'Charting a dynamic DNA methylation landscape of the human genome' is a major milestone in epigenomics as it shines light on when, where and how many CpG's participate in genomic regulation. The group mapped most of the 28-million CpG's found among the 3-billion nucleotides that make up human DNA in 30 different cell and tissue types. The majority of the sites are unchanged but the ones that are changed are in locations that are likely important for gene expression. Now that they have identified these differentially methylated regions (DMR's) they believe they will be able to perform more directed methylation analysis on these regions. This means they will not have to perform complete sequencing on all of the more than 200 different human cell types but can instead concentrate on these DMR's and still discover the differences between the cell types.