MALDI METHYL MAPPING:
Courtesy of Human Epigenome Consortium
The Human Epigenome Project's pilot study included the development of novel approaches to mapping methylation across the genome. Researchers hope the so-called GOOD assay for epigenotyping, diagrammed here, can be used to identify particular CpG positions whose methylation status is indicative of the larger region's genomic state.
Methylation at regulatory regions, especially promoters, correlates with transcriptional activity: Sequences near silent genes generally are methylated, whereas those near active regions are not. Scientists traditionally have measured these modifications on a gene-by-gene basis, but a team at the Wellcome Trust Sanger Center in Cambridge, UK, has been attacking the question on a genomic scale. This project, dubbed the Human Epigenome Project, released its first results in December 2004.1
Vardhman Rakyan led the pilot study. He and his colleagues examined DNA methylation patterns in the human major histocompatibility complex (MHC) in seven human tissues:...