C. elegans RNAi Service

RNA Interference (RNAi ) is widely used by researchers of the past decade in functional genomics. As one of the most important breakthroughs in molecular biology, RNAi technology allows us to directly observe specific gene silencing in eukaryotes. The phenomenon of RNAi is highly conserved among species. Since the groundbreaking discovery of RNAi in C. elegans, the model organism C. elegans has been widely used to study the mechanism of RNAi.

How it works

Extensive genetic and biochemical analysis revealed a two-step mechanism of RNAi-induced gene silencing. First, degradation of dsRNA into small interfering RNAs (siRNAs, 21~25 nt), by an RNase III-like activity. Second, the siRNAs join an RNase complex, RISC (RNA-induced silencing complex), which acts on the cognate mRNA and degrades it.

Figure 1. Mechanism of RNA interference (RNAi) - CD BioSciences

RNAi in C. elegans

Nowadays, RNAi has been applied to systematically shut down the expression of each gene to conduct genome-wide screens in C. elegans. For RNAi, double-stranded RNA (dsRNA) can be introduced in the worms by injection, soaking or feeding.

- Microinjections. dsRNA can be injected into the intestine, gonad, or body cavity. Because the injected worms must be examined at different time points to determine the optimum screening time, microinjections are not practical for performing large-scale RNAi screens.

- Soaking. Soaking the worms in a concentrated solution of dsRNA also induces RNAi as dsRNA is ingested through the pharynx. The soaking approach is not as tedious as microinjections and also amenable to high throughput screening. However, it is expensive due to a large amount of in vitro transcribed dsRNA required for soaking the worms.

- Feeding. dsRNA transcription can be ingested by C.elegans. This procedure is performed on petri plates or in liquid culture. RNAi by feeding in liquid culture is ideal for scoring easily observable phenotypes such as sterility, lethality, slow growth and dramatic changes in GFP expression. RNAi screens by feeding are far less labor-intensive and also inexpensive and are commonly used.

Workflow of C. elegans RNAi service

• Speak with our experts to determine an RNAi C. elegans model strategy.
• Design and synthesize siRNAs/shRNA.
• RNAi expression vector construction.
• RNAi introduced in C. elegans by injecting, soaking or feeding.
• Screening and identification (via PCR, western blot or luciferase assay).
• Deliver the final C. elegans model and validation report, which describes the details of RNAi and shows evidence of the gene silencing.

Available services

• RNAi design and synthesis service
  - Chemically Synthesized siRNAs
  - Vector Mediated shRNAs
  - Lentivirus-mediated RNAi
• RNAi transfection optimization service
  - Microinjection
  - Soaking
  - Feeding
• RNAi interference effect detection service
  - PCR
  - Western Blot
  - Luciferase Assay

CD BioSciences offers commercially synthesized siRNAs to silence virtually any gene in C. elegans, dramatically accelerating the pace of your research. siRNAs services are performed by a group of specially trained and experienced scientists in a streamlined workflow. If you are interested in our services, please contact us for more details. We are glad to serve you!

References

1. Agrawal N, et al. (2003). "RNA interference: biology, mechanism, and applications". Microbiol Mol Biol Rev. 67(4):657‐685.
2. Conte D Jr, et al. (2015). "RNA Interference in Caenorhabditis elegans". Curr Protoc Mol Biol. 109:26.3.1‐26.3.30.

Related Sections

• http://rnaiweb.com/
  The RNAi Web - A resource center for RNA interference (RNAi) technology.
• http://rna.tbi.univie.ac.at/cgi-bin/RNAxs/RNAxs.cgi
  RNAxs- A site to design potent siRNAs to knock down your gene(s) of interest. Includes all the parameters that have been shown to influence RNAi efficiency in literature.
• http://www.rnai.org
  The RNAi database is a searchable database of ovary or germline-enriched genes by gene or by phenotype.
• http://c.elegans.tripod.com/RNAi.htm
  The ten.snagele@iANR page has many informative links for RNAi in C. elegans and other organisms.
• http://www.silencinggenomes.org/
  Silencing Genomes - Cold Spring Harbor's guide to RNAi in C. elegans.

* For research use only.