RNA interference (RNAi) is an evolutionarily conserved process through which double-stranded RNA (dsRNA) induces the silencing of cognate genes (for review, see Bernstein et al. 2001b; Carthew 2001). Sources of dsRNA silencing triggers include experimentally introduced dsRNAs, RNA viruses, transposons, and RNAs transcribed from complex transgene arrays (for review, see Hammond et al. 2001b). Sh...

In RNA-mediated interference (RNAi), double-stranded RNAs (dsRNAs) target complementary mRNAs for degradation. New work demonstrates that essential chromosomal functions are mediated through RNAi protein components and short RNAs, which alter chromosome function at specific DNA loci via histone modification.

In fission yeast, RNA interference (RNAi)-dependent heterochromatin formation silences transgenes inserted at centromeres. In this issue, Bühler et al. (2007) demonstrate that the RNAi machinery directly targets transgene transcripts. Furthermore, they link transgene silencing to a protein complex resembling the TRAMP complex of budding yeast, which promotes transcript degradation via the exoso...

Craig C. Mello is an American developmental biologist and Nobel Laureate, who helped discover RNA interference [4] (RNAi). Along with his colleague Andrew Fire [5], he developed gene knockouts using RNAi. In 2006 Mello won the Nobel Prize in Physiology or Medicine [6] for his contribution to the discovery of RNAi. Mello also contributed to developmental biology, focusing on gene regulation [7],...

In plants, the RNA interference (RNAi) machinery responds to a variety of triggers including viral infection, transgenes, repeated elements and transposons. All of these triggers lead to silencing outcomes ranging from mRNA degradation to translational repression to chromatin remodeling. Thus, plants offer us a potentially unique opportunity to understand the full range of RNAi effector mechani...

RNA interference (RNAi) is a mechanism for sequence-specific gene silencing guided by double-stranded RNA. In plants and insects it is well established that RNAi is instrumental in the response to viral infections; whether RNAi has a similar function in mammals is under intense investigation. Recent studies to address this question have identified some unanticipated interactions between the RNA...

Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are sequence-specific post-transcriptional regulators of gene expression. Although major components of the RNA interference (RNAi) pathway have been identified, regulatory mechanisms for this pathway remain largely unknown. Here we demonstrate that the RNAi pathway can be modulated intracellularly by small molecules. We have developed a cel...

Nuclear RNA interference (RNAi) is mediated by the canonical RNAi machinery and can lead to transcriptional silencing, transcriptional activation, or modulation of alternative splicing patterns. These effects transpire through changes in histone and DNA modifications via RNAi-mediated recruitment of chromatin-modifying enzymes. To prove that nuclear RNAi occurs and modulates transcription in hu...

Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are sequence-specific post-transcriptional regulators of gene expression. Although major components of the RNA interference (RNAi) pathway have been identified, regulatory mechanisms for this pathway remain largely unknown. Here we demonstrate that the RNAi pathway can be modulated intracellularly by small molecules. We have developed a cel...

RNA interference (RNAi), an evolutionarily conserved mechanism triggered by double-stranded (dsRNA), causes gene silencing and inhibit translation in a sequence-specific manner. This technique was first time discovered Nematode Caenorhabditiselegans.The specificity robustness of RNAi have immense interest using as tool various settings which results intovarious significantachievements the area ...