|
|  |
RNA-mediated Interference (RNAi):
The Ultimate Gene Silencing Technology
RNAi, or RNA-mediated interference, is the new
method of choice for achieving targeted gene silencing in a wide range
of experimental systems from plants to human cells. Previous gene
silencing methods such as antisense and ribozyme-based approaches
suffered from poor experimental reproducibility, lack of robustness and
limited upscalability. Not only has RNAi largely overcome these
hurdles, it has in fact revolutionized the process of identifying and
functionally characterizing new genes, thereby offering the best new
functional genomics tool available for realizing the full promise of
the Human Genome Project.
Initially discovered in 1998 by Fire and Mello's breakthrough
work in the nematode C. elegans,
itself following several related observations from other groups
studying plants and fungi, RNAi is now recognized as part of a highly
catalytic gene regulation
system found in most organisms from plants to human, and thought to
have evolved at least in part as a defence mechanism against molecular
pathogens. For this landmark discovery, Mello and Fire were honored
with the 2006 Nobel Prize in Physiology and Medicine.
 The pathway mounts a powerful cellular
response to
the presence of double-stranded RNA (dsRNA) molecules, which, in
nature, would most likely derive from active transposons, viruses, or
endogenously-encoded microRNAs. These dsRNAs are processed and used by
the cell's RNAi machinery as targeting co-factors to identify
complementary messenger
RNA (mRNA) molecules, which are then completely degraded, thereby
silencing the expression of the corresponding gene.
Thus, by introducing dsRNAs containing targeted gene sequences into
cells or organisms, the RNAi pathway can be experimentally "harnessed"
to silence essentially any gene of interest with tightly controlled
specificity. The detailed analysis of resulting loss-of-functions
phenotypes represents arguably the most direct and most readily
interpretable method for experimentally elucidating the cellular
function of genes in most systems today.
|
|
|
|
|
|
 |
|
 |
|
|
|
RNAi technology offers an unprecedented
combination of:
- High silencing efficacy
- Nucleotide sequence-based targeting specificity
- Excellent reproducibility and robustness
- Scalability for large scale screening studies
- Wide cross-species applicability
|
|
|
|
|
 |
|
 |
|
|
|
|
|
|
 |
