Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetically engineered mosquitoes show resistance to dengue fever virus

10.03.2006


Researchers create new tool against transmission of virus



Researchers have successfully created a genetically engineered mosquito that shows a high level of resistance against the most prevalent type of dengue fever virus, providing a powerful weapon against a disease that infects 50 million people each year.

Anthony James, a UC Irvine vector biologist, is one of a team of researchers who injected DNA into mosquito embryos, creating the first stable transgenic mosquito resistant to Type 2 dengue fever virus, the most prevalent strain of the disease. The mosquitoes that survived the procedure also remained fertile and were able to reproduce, a key factor for any future strategies that may involve replacing mosquito populations with their genetically modified counterparts.


The results were published this week in the early online edition of the Proceedings of the National Academy of Sciences.

“These results are very exciting because they provide us a genetic tool we can use to control mosquito-borne diseases such as dengue fever,” James said. “We have been working for some time on the individual components of creating a genetically modified mosquito that would fend off dengue infection, but this is the first time we have brought all the pieces together to create a stable model that can also reproduce.”

In the study, the researchers exploited a vulnerability of the dengue virus to make the mosquitoes resistant to infection. This vulnerability occurs when the virus replicates and its single strand of RNA – a chemical cousin of DNA – briefly becomes double–stranded. At this point, the virus is vulnerable because of a naturally occurring protein called dicer-2. This protein initially has no effect on a single strand of RNA, but acts like scissors on the double strand, chopping it up and rendering its genetic material useless. Once this process is started, the single-stranded RNA also becomes vulnerable to dicer-2 and is cut up, thereby preventing further virus replication.

On its own, this process of self-destruction happens only after the virus has already replicated and been transmitted; however, the researchers found a way to control and speed up the process. They accomplished this by cloning a section of the virus’ RNA and injected two inverse copies of it into mosquito embryos. The copies formed a double-stranded RNA, which, as expected, bound with dicer-2 and was chopped up. The virus never had the opportunity to replicate. As a result, they could “inoculate” mosquitoes with a form of the virus that would essentially be benign.

Joining James on the study, funded by a 2001 grant from the National Institutes of Health, were researchers from Colorado State University and from Virginia Polytechnic Institute and State University.

James and his colleagues performed tests on a family of mosquitoes descended from one of the original embryos that survived the procedure. They found that the vast majority of that family was highly resistant to dengue infection. They also were able to detect the engineered RNA in the mosquitoes, a sign that the genetic alteration had been successful and passed down through reproduction. Furthermore, when that genetic modification was reversed, the mosquitoes were as susceptible to the virus as they had been before the procedure.

Dengue fever is endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia and the Western Pacific. The virus is transmitted to people by mosquitoes of the species Aedes aegypti. The World Health Organization estimates 50 million cases of dengue infection each year. Approximately 20,000 people die annually from the disease.

James, a professor of microbiology and molecular genetics, and of molecular biology and biochemistry, has made a number of significant advances on genetic approaches to interrupt malaria parasite and dengue virus transmission by mosquitoes. He has received a number of international awards for his research.

In 2005, he received a $19.7 million grant from the Foundation for the National Institutes of Health to lead an international effort to develop new methods to control the transmission of dengue fever. The project is among 43 groundbreaking research projects to improve health in developing countries, supported by $436 million for the Grand Challenges in Global Health Initiative, launched by the Bill and Melinda Gates Foundation.

According to James, the next step of this research will be to use the FNIH grant to explore population replacement strategies using the genetically modified mosquitoes. He stressed that no genetically altered mosquitoes will be released at any time during these studies.

About the University of California, Irvine: The University of California, Irvine is a top-ranked university dedicated to research, scholarship and community service. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 24,000 undergraduate and graduate students and about 1,400 faculty members. The second-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3.3 billion.

Farnaz Khadem | EurekAlert!
Further information:
http://www.today.uci.edu
http://www.uci.edu

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>