Mapping methylation

© Cell Press

X. Zhang et al., "Genome-wide high-resolution mapping and functional analysis of DNA methylation in Arabidopsis," Cell, 126:1189-201, 2006. (Cited in 94 papers)

The researchers created a Web tool to view the DNA methylation and gene expression data. "It's extremely useful," says Jerzy Paszkowski of the University of Geneva, who last year used the Web tool to show that methylation controls inheritance of epigenetic information (Cell, 130:851-62, 2007).

The initial DNA methylation map had a resolution of only 35 bp. Earlier this year, both Jacobsen's and Ecker's teams separately used new sequencing techniques to develop new methylome maps with single-base resolution. "Now with sequencing you can see the absolute context of where methylation takes place," says Ecker.

Both the 2006 and 2008 methylomes provide only "snapshots" of average DNA methylation across the whole plant, says Hanspeter Schöb of the University of Zurich. To understand epigenetic regulation during development, more tissue-specific methylation patterns are needed, he says.