WHAT IS THIS?

[mith]

What is siRNA and RNAi?

[DevGrp]

small interfering RNA (siRNA), RNA interference (RNAi) also called RNA silencing

Its the phenomenom by which introduced double stranded RNA has the effect of silencing expression of any genes encoding mRNAs with similar sequences. It's probably a viral defence mechanism but is useful because you can introduce an siRNA molecule , or siRNA producing vector into a cell and switch off down expression of the genes you wish to study.


In our hands in plants its more of a turn down rather than a switch off, so we were able to study the effects of reduced gene expression when a complete knockout would have been lethal.

Hope this helps

[mith]

Very interesting, where do you work if you don't mind my asking?

[DevGrp]

http://www.cnap.org.uk/

[2810712]

How does this happen?

It's probably a viral defence mechanism but is useful because you can introduce an siRNA molecule , or siRNA producing vector into a cell and switch off down expression of the genes you wish to study.
And are you saying that this is antiviral?

hrushikesh

[DevGrp]

Yep appears to be a cellular antiviral mechanism



Pubmed:

http://www.ncbi.nlm.nih.gov/entrez/quer ... s=12554663

and reviewed in Trends in Genetics
RNA silencing as a plant immune system against viruses
Olivier Voinnet
Trends in Genetics 17:449 (2001)

http://www.sciencedirect.com/science?_o ... e9e26026b3

[GreenDog]

Maybe it appears to be an antiviral mechanism, but is probably not, is serves a much more basic function in development.
The phenomenon exists in fungi- called quelling, in plants- PTGS, and in C. Elegans.
Two major participants in the system Dicer (dsRNA endonuclease) and RISC (RNA-Induced Silencing Complex), have roles that affect gene expression, and not only virus response uses.
PTGS - Posttranscriptional gene silencing in plants and 'quelling' in fungi are plant-based RNAi mechanisms.

[yykang]

more and more proofs surport that RNAi is a antiviral mechanism in organism. I think the further study should focus on the application for gene therapy and gene function study.

[TairaKawasaki]

How do you think dsRNA effect on adult neuron.

We have found a strange coincide in Fig.4 on
Cell. 2004 Mar 19;116(6):779-93.
MID:15035981

Please check it by your own eyes.