Fig. 1. The methylation profile of a 100-kb region of Arabidopsis. Profiling was accomplished by hybridizing a microarray with total genomic DNA and genomic DNA depleted of methylated sequences; the ratio is plotted. Annotated genes are light gray (boxed) annotated transposons are dark gray. Expression is also plotted in WT (light gray) and in DNA methylation mutants (dark gray). Only transposons are affected by loss of methylation (Lippman et al., 2004).