RNA silencing

RNA silencing (associated with the concept of post-transcriptional gene silencing or RNA interference) refers to a family of gene silencing effects by which gene expression is negatively regulated by non-coding RNAs such as microRNAs. It may also refer to the introduction of a synthetic antisense RNA molecule used in scientific experiments on gene expression. RNA silencing may also be defined as sequence-specific regulation of gene expression triggered by double-stranded RNA (dsRNA). RNA silencing mechanisms are highly conserved in most eukaryotes. The most common and well-studied example is RNA interference (RNAi), in which endogenously expressed microRNA (miRNA) or exogenously derived small interfering RNA (siRNA) induces the degradation of complementary messenger RNA. Other classes of small RNA have been identified, including piwi-interacting RNA (piRNA) and its subspecies repeat associated small interfering RNA (rasiRNA).