DNA Methylation in Plants: Relationship to Small RNAs and Histone Modifications, and Functions

DNA methylation is a type of epigenetic marking that strongly influences chromatin structure and gene expression in plants and mammals. Over the past decade, DNA methy-lation has been intensively investigated in order to elucidate its control mechanisms. These studies have shown that small RNAs are involved in the induction of DNA methylation, that there is a relationship between DNA methylation and histone methylation, and that the base excision repair path-way has an important role in DNA demethylation. Some aspects of DNA methylation have also been shown to be shared with mammals, suggesting that the regulatory path-ways are, in part at least, evolutionarily conserved. Considerable progress has been made in elucidating the mechanisms that control DNA methylation; however, many aspects of the mechanisms that read the informatio