Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists develop new RNAi knockdown technology

02.06.2003


Scientists from the RIKEN Tsukuba Institute (Japan) have developed a valuable new experimental system for tissue-specific RNAi knockdown in mammalian cells and organisms – a discovery that will markedly advance the functional characterization of genes involved in development and disease.



Discovered in the late nineties, RNA intereference (RNAi) refers to the introduction of double-stranded RNA (dsRNA) into a cell, where it induces the degradation of complementary mRNA, and thereby suppresses gene expression. RNAi has proven to be a powerful tool in the elucidation of gene function in organisms ranging from worms, to plants and fruit flies.

However, the use of RNAi in mammals has been complicated by the antiviral response of mammalian cells to dsRNA. The presence of foreign dsRNA in a mammalian cell initiates the so-called "interferon response:" the non-specific degradation of mRNA, and ensuing death of the cell. Mammalian RNAi researchers have undertaken a few different routes to avoid eliciting the interferon response, and while some have been successful, none have been able to accomplish it in a tissue-specific manner. Until now.


As published in the June 1 issue of Genes & Development, Dr. Shunsuke Ishii and colleagues have constructed a new RNAi vector (a vehicle to introduce foreign RNA into a cell), which both side steps the interferon response and allows for the tissue-specific suppression of gene expression. This vector, called pDECAP, represents a dramatic improvement over current RNAi transgenic technology.

As Dr. Ishii explains, "In the RNAi transgenic systems developed so far, small hairpin-type RNA is expressed from the RNA polymerase III promoter or the virus promoter. However, these systems cannot be utilized to knockdown gene function in a tissue-specific manner, because these promoters are active in all types of cells. In our system, the RNA polymerase II promoter is utilized to express hairpin-type double-strand RNA (dsRNA). Therefore, our system can be used to generate the tissue-specific knockdown mice."

The pDECAP vector expresses dsRNA from an RNA polymerase II promoter, which can be actived in specific cell types. Therefore, Dr. Ishii and colleagues can pick and choose which tissues that they want to knockdown gene function in. To avoid the interferon response, Dr. Ishii and colleagues engineered the vector to transcribe dsRNA that lacks the sequences needed to export it from the nucleus into the cytosol. Instead, pDECAP-expressed dsRNA is sequestered in the nucleus, where it is processed into small interfering RNAs (siRNAs). These siRNAs are then released into the cytosol, where they direct the degradation of target mRNA without eliciting the interferon response.

Dr. Ishii and colleagues used the pDECAP system to suppress expression of the Ski oncogene in mice. These Ski-knockdown mice largely recapitulate the mutant phenotype of traditional Ski-knockout mice (in which the Ski gene has been deleted through homologous recombination of embryonic stem cells), suggesting that Dr. Ishii’s new system provides an efficient alternative to traditional mouse knockouts in the exploration of gene function.

Heather Cosel | EurekAlert!
Further information:
http://www.cshl.org/

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Colliding lasers double the energy of proton beams

Researchers from Sweden's Chalmers University of Technology and the University of Gothenburg present a new method which can double the energy of a proton beam produced by laser-based particle accelerators. The breakthrough could lead to more compact, cheaper equipment that could be useful for many applications, including proton therapy.

Proton therapy involves firing a beam of accelerated protons at cancerous tumours, killing them through irradiation. But the equipment needed is so large and...

Im Focus: New studies increase confidence in NASA's measure of Earth's temperature

A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.

The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

AI and high-performance computing extend evolution to superconductors

27.05.2019 | Information Technology

Meteor magnets in outer space

27.05.2019 | Physics and Astronomy

Coat of proteins makes viruses more infectious and links them to Alzheimer's disease

27.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>