Gene silencing: Double-stranded RNA mediated mRNA degradation and gene inactivation

¹North Carolina State University, Forest Biotechnology Group, Raleigh, NC 27695, USA
²University of North Carolina, Department of Cell and Developmental Biology, Chapel Hill, NC 27599, USA

The recent development of gene transfer approaches in plants and animals has revealed that transgene can undergo silencing after integration in the genome. Host genes can also be silenced as a consequence of the presence of a homologous transgene. More and more investigations have demonstrated that double-stranded RNA can silence genes by triggering degradation of homologous RNA in the cytoplasm and by directing methylation of homologous nuclear DNA sequences. Analyses of Arabidopsis mutants and plant viral suppressors of silencing are unraveling RNA-silencing mechanisms and are assessing the role of methylation in transcriptional and posttranscriptional gene silencing. This review will focus on double-stranded RNA mediated mRNA degradation and gene inactivation in plants.

Key words: Gene silencing, double-stranded RNA, methylation, homologous RNA, transgene.