Related Experiment Video
Updated: Aug 8, 2026
08:25
Phage-mediated Delivery of Targeted sRNA Constructs to Knock Down Gene Expression in E. coli
Published on: March 20, 2016
Gene silencing by double-stranded RNA
1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. carthew+@pitt.edu
Current Opinion in Cell Biology
|March 15, 2001
Summary
Gene silencing in eukaryotes involves targeted mRNA degradation triggered by double-stranded RNA. This process, known as RNA interference (RNAi), utilizes small RNA fragments to guide an enzyme that cleaves specific messenger RNAs.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Eukaryotes possess a mechanism to silence gene expression when encountering double-stranded RNA (dsRNA) homologous to a target gene.
- This gene silencing is primarily achieved through the specific degradation of messenger RNA (mRNA).
Purpose of the Study:
- To elucidate the biochemical mechanism underlying dsRNA-induced gene silencing in eukaryotes.
- To identify the key molecular players and intermediates involved in this process.
Main Methods:
- Biochemical assays were employed to replicate the gene silencing phenomenon in vitro.
- Analysis of RNA fragments generated from dsRNA and their association with cellular components.
Main Results:
- Double-stranded RNA is processed into small RNA fragments of 21--23 nucleotides.
- These small RNA fragments associate with an RNA endonuclease, acting as a guide for mRNA targeting.
- Targeted mRNA molecules are cleaved at specific sites, spaced 21--23 nucleotides apart.
Conclusions:
- The described mechanism, termed RNA interference (RNAi), is a conserved biological process in eukaryotes.
- RNAi plays roles in antiviral defense, gene cosuppression, and the regulation of transposable elements.
Related Concept Videos
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
01:23RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
01:23RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
02:30siRNA - Small Interfering RNAs
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
02:15Experimental RNAi
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
02:30Small interfering RNAs (siRNA)
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...