Chapter category: RNA
Post-Transcriptional Gene Silencing in Plants
Noncoding RNAs: Molecular Biology and Molecular Medicine
Edited by: Jan Barciszewski and Volker A. ErdmannISBN: 0-306-47835-8
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Chapter authors:
Matthew Escobar and Abhaya M. Dandekar
Accumulating genetic and biochemical evidence suggests that antisense-mediated gene silencing, cosuppression, RNA interference and virus-induced gene silencing are all unique inputs into a common RNA silencing pathway triggered by double stranded RNA. This pathway, termed post-transcriptional gene silencing (PTGS) is characterized by accumulation of 21-25 nt small-interfering RNAs, sequence-specific degradation of target mRNAs, and methylation of target gene sequences. PTGS appears to be ancient and highly conserved, as several groups of homologous genes required for silencing in plants, animals, and fungi have been identified. Though biochemical dissection of PTGS is still in its infancy, several key activities have been identified, such as Dicer, the endonuclease responsible for synthesis of short-interfering RNAs, and RISC, the nucleoprotein complex which mediates mRNA degradation. Several lines of evidence suggest that PTGS plays a key role in viral defense in plants, but further study is required to investigate the intriguing possibility that PTGS can act as an endogenous gene control mechanism.
Matthew Escobar
Department of Pomology, University of California, Davis, California, U.S.A.
Abhaya M. Dandekar
Department of Pomology, University of California, Davis, California, U.S.A.
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