A Role for RNAi in the Selective Correction of DNA Methylation Defects

• DOI: 10.1126/science.1165313
• Publication Date: 2009-01-30T02:10:48Z
• Authors: Felipe Karam Teix...; Fabiana Heredia; Alexis Sarazin; François Roudier; Martine Boccara; Constance Ciaudo; Corinne Cruaud; Julie Poulain; Maria Berdasco; Mario F. Fraga; Olivier Voinnet; Patrick Wincker; Manel Esteller; Vincent Colot
• Keywords: RNA-Directed DNA Methylation; Epigenomics

DNA methylation is essential for silencing transposable elements and some genes in higher eukaryotes, which suggests that this modification must be tightly controlled. However, accidental changes can transmitted through mitosis (as cancer) or meiosis, leading to epiallelic variation. We demonstrated the existence of an efficient mechanism protects against transgenerational loss Arabidopsis. Remethylation specific subset heavily methylated repeats are targeted by RNA interference (RNAi) machinery. This process does not spread into flanking regions, usually progressive over several generations, faithfully restores wild-type target sequences RNAi-dependent manner. Our findings suggest important role RNAi protecting genomes long-term epigenetic defects.