Loss of RNA-dependent RNA polymerase 2 (RDR2) function causes widespread and unexpected changes in the expression of transposons, genes, and 24-nt small RNAs.

ABSTRACT: Transposable elements (TEs) comprise a substantial portion of many eukaryotic genomes and are typically transcriptionally silenced. RNA-dependent RNA polymerase 2 (RDR2) is a component of the RNA-directed DNA methylation (RdDM) silencing pathway. In maize, loss of mediator of paramutation1 (mop1) encoded RDR2 function results in reactivation of transcriptionally silenced Mu transposons and a substantial reduction in the accumulation of 24 nt short-interfering RNAs (siRNAs) that recruit RNA silencing components. An RNA-seq experiment conducted on shoot apical meristems (SAMs) revealed that, as expected based on a model in which RDR2 generates 24 nt siRNAs that suppress expression, most differentially expressed DNA TEs (78%) were up-regulated in the mop1 mutant. In contrast, most differentia

SUBMITTER: Jia Y 

PROVIDER: S-EPMC2774947 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature