How does RNA interference (RNAi) function in gene expression and regulation?

RNA interference (RNAi) regulates gene expression by degrading mRNA and preventing translation.

RNA interference (RNAi) is a natural process that regulates gene expression by degrading mRNA and preventing translation. It is a post-transcriptional gene silencing mechanism that is triggered by double-stranded RNA (dsRNA). The dsRNA is processed by an enzyme called Dicer into small interfering RNAs (siRNAs) that are 21-23 nucleotides in length. These siRNAs are then incorporated into the RNA-induced silencing complex (RISC), which targets complementary mRNA for degradation.

RNAi plays a crucial role in many biological processes, including development, differentiation, and defence against viruses and transposable elements. It also has potential therapeutic applications, as it can be used to silence disease-causing genes.

RNAi can be induced experimentally by introducing synthetic siRNAs or by expressing short hairpin RNAs (shRNAs) that are processed into siRNAs. This has led to the development of RNAi-based therapies for various diseases, including cancer and viral infections.

In conclusion, RNA interference (RNAi) is a powerful mechanism for regulating gene expression by degrading mRNA and preventing translation. It has important biological roles and potential therapeutic applications.