 RNA-directed DNA methylation

RNA-directed DNA methylation, or RdDM, is a plant regulatory pathway in which small RNAs guide methylation of homologous DNA. Canonical components include Pol IV, RDR2, DCL3 and Pol V, connecting production of small RNAs with recognition of target chromatin.

Noncoding transcription can supply scaffold transcripts at the target, rather than serving only to produce a protein. Experiments on specialized polymerases showed how this transcriptional activity participates in silencing adjacent or overlapping regions.^[ref]