Short Interfering RNA

Background information RNA interference (RNAi) was first discovered in Cenorhabditis elegans about 10 years ago and has since revolutionized genetic function analysis. This discovery has launched a process in which scientists use known gene sequences for research and attempt to determine their biological function by destroying their in vivo activity. It involves the introduction of homologous double stranded RNA (dsRNA) to specifically target the product of the gene and destroy its function in vivo.

Small interfering RNA (siRNA) is a double-stranded RNA of about 21-25 nucleotides. They are known to be important intermediates in causing RNA interference in invertebrates. The siRNA has a characteristic structure with 5 * phosphate groups ** - hydroxyl ends and 2 bases 3 * overhangs on each strand of the duplex. (Caplen et al., 2009) The results of this study suggest that histone octamer is not an unimpaired obstacle to the passage of RNA polymerase, and that octamers can move around the enzyme without releasing control of their DNA Respectively. . For longer templates, the octamer can migrate to any vacancy on DNA, which can be controlled by the "closed loop" probability. However, the use of short DNA fragments limits the final position available for octamers (Felensfeld et al 1996).

An intercellular gene silencing mechanism called RNA silencing (RNAi) or posttranscriptional gene silencing (PTGS) is a small set of small molecules such as small interfering RNA (siRNA), Piui interacting RNA (piRNA) or miRNA It is well known that it is directed by small RNAs. Basically, they work with a similar mechanism, the differences being mainly in their intracellular biosynthesis (Ender and Meister, 2010). Production of mature miRNA has undergone several steps: transcription from DNA by RNA polymerase II with a longer sequence of primary miRNA (pri-miRNA). After transcription, the pre-miRNA is further processed into precursor miRNA (pre-miRNA) of about 60 nucleotides by the enzymes Dorsa and DGCR8 protein complex (Lee et al., 2003). Once the pre - miRNA is produced in the nucleus, it is transported to the nucleus in a Ran - GTP - dependent manner via the protein Extinin 5 (Lund et al., 2004).