Genome-scale DNA methylation maps of pluripotent and differentiated cells

DNA methylation, an important mechanism of epigenetic modification that produces different patterns of gene expression from a single DNA sequence, is vital to normal development and its malfunction can cause cancer and other abnormalities. A map of DNA methylation in embryonic stem cells, and in various cell types derived from them, has now been produced at nucleotide resolution using high-throughput bisulphite sequencing combined with single molecule-based sequencing. The map reveals specific sites in the genome where methylation changes as cells develop, for instance when embryonic stem cells mature into nerve cells. More generally, the methodology will be of value for the epigenetic profiling of cell populations relevant to developmental biology, cancer and regenerative medicine.