Cell type-specific DNA methylation patterns are established during mammalian
development and maintained in adult somatic cells. Understanding how these patterns of 5-
methylcytosine are established and maintained requires the elucidation of mechanisms for
both DNA methylation and demethylation. The enzymes involved in the de novo methylation
of DNA and the maintenance of the resulting methylation patterns have been fairly well
characterized. However, important remaining challenges are to understand how DNA …