DNA methyltransferases are required to induce heterochromatic re-replication in Arabidopsis.

• Main Authors: Hume Stroud, Christopher J Hale, Suhua Feng, Elena Caro, Yannick Jacob, Scott D Michaels, Steven E Jacobsen
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2012-07-01
• Series: PLoS Genetics
• Online Access: http://europepmc.org/articles/PMC3390372?pdf=render

The relationship between epigenetic marks on chromatin and the regulation of DNA replication is poorly understood. Mutations of the H3K27 methyltransferase genes, Arabidopsis trithorax-related protein5 (ATXR5) and ATXR6, result in re-replication (repeated origin firing within the same cell cycle). Here we show that mutations that reduce DNA methylation act to suppress the re-replication phenotype of atxr5 atxr6 mutants. This suggests that DNA methylation, a mark enriched at the same heterochromatic regions that re-replicate in atxr5/6 mutants, is required for aberrant re-replication. In contrast, RNA sequencing analyses suggest that ATXR5/6 and DNA methylation cooperatively transcriptionally silence transposable elements (TEs). Hence our results suggest a complex relationship between ATXR5/6 and DNA methylation in the regulation of DNA replication and transcription of TEs.