RNA interference (RNAi) can still be regarded as a recently discovered phenomenon, but it has already made its way as a widely used method in molecular biology. In 1998, Andrew Fire and Craig Mello were the first to describe the mechanism of RNAi in the nematode C. elegans (Fire et al, 1998). Long double-stranded RNA molecules were found to mediate posttranscriptional silencing of genes with a ...

In most eukaryotes, histone and DNA modifications are responsible for the silencing of genes integrated in heterochromatic sequences, as well as the silencing of pericentromeric repeats and transposable elements themselves. But the mechanisms that guide these modifications to heterochromatin during the cell cycle have been elusive. RNA interference takes advantage of heterochromatic transcripti...

Small RNA molecules regulate eukaryotic gene expression during development and in response to stresses including viral infection. Specialized ribonucleases and RNA-binding proteins govern the production and action of small regulatory RNAs. After initial processing in the nucleus by Drosha, precursor microRNAs (pre-miRNAs) are transported to the cytoplasm, where Dicer cleavage generates mature m...

CRISPR-Cas systems provide a small RNA-based mechanism to defend against invasive genetic elements in archaea and bacteria. To investigate the in vivo mechanism of RNA interference by two type III-B systems (Cmr-α and Cmr-β) in Sulfolobus islandicus, a genetic assay was developed using plasmids carrying an artificial mini-CRISPR (AC) locus with a single spacer. After pAC plasmids were introduce...

objective: nucleostemin (ns) is a recently identified gene that is expressed mainly in the nucleoli of neuronal, embryonic and mesenchymal stem cells which plays a role in their self renewal. over expression of this gene has been reported in several cancer cell lines tumoral tissues including gastric, hepatic and prostate cancer. in this study, we investigated the effects of suppression of this...