The gene for domains rearranged methyltransferase (DRM2) in Arabidopsis thaliana plants is methylated at both cytosine and adenine residues

The methylation patterns of cytosine and adenine residues in the Arabidopsis thaliana gene for domains rearranged methyltransferase (DRM2) were studied in wild-type and several transgene plant lines containing antisense fragments of the cytosine DNA-methyltransferase gene METI under the control of copper-inducible promoters. It was shown that the promoter region of the DRM2 gene is mostly unmethylated at the internal cytosine residue in CCGG sites whereas the 3'-end proximal part of the gene coding region is highly methylated. The DRM2 gene was found to be also methylated at adenine residues in some GATC sequences. Cytosine methylation in CCGG sites and adenine methylation in GATC sites in the DRM2 gene are variable between wild-type and different transgenic plants. The induction of antisense METI constructs with copper ions in transgene plants in most cases leads to further alterations in the DRM2 gene methylation patterns.