How does rnai effect gene expression?
RNAi (RNA interference) is a process dominated by small RNA which effect the gene expression at post transcription level.
RNAi is dominated by small RNA like (shRNA and miRNA), these RNA are synthesized inside the cell as well as can be introduced out from the cell.
what these small RNA does is they form a RISC complex which then goes and binds to various target mRNA which have complementarity to them and then employ two different strategies
- stop the translation
- tag the mRNA for degradation by endonucleases.
through these two strategies small RNA interfere with the gene expression in the cell.
below video is a good way to understand whole concept. WATCH THIS VIDEO