DNA methylation dynamics in health and disease

DNA methylation is an epigenetic mark that is erased in the early embryo and then reestablished in each individual, through a developmentally regulated program mediated by sequence information and trans-acting factors that direct the de novo DNA methylation and demethylation machinery to its targets in a dynamic manner. Once established, these patterns can be maintained in a stable manner over the lifetime of the organism. Additional changes in methylation that occur during aging and as part of disease processes may also be directed by similar molecular rules using the same complex machinery.