Second door discovered in war against mosquito-borne diseases

Jul 08, 2013
MSU researchers have discovered a second molecular door that could turn the tide against mosquito-borne diseases. Credit: Kurt Stepnitz

(Phys.org) —In the global war against disease-carrying mosquitoes, scientists have long believed that a single molecular door was the key target for insecticide. This door, however, is closing, giving mosquitoes the upper hand.

In this week's Proceedings of the National Academy of Sciences, a team of researchers led by Michigan State University has discovered a second gateway that could turn the tide against the mosquitoes' growing advantage.

For many years, have been deployed in developing countries to fend off diseases such as malaria, dengue fever and more. They're so effective that they are the only insecticides the World Health Organization uses with their they distribute around the globe.

"Pyrethroids are effective because they eliminate mosquitoes while having few if any side effects on humans," said Yuzhe Du, MSU electrophysiologist and one of the lead authors. "Our discovery of a second receptor in the mosquitoes' sodium channel gives us a better understanding of how the insecticide works at a molecular level as well as could lead to ways to stem mosquitoes' resistance to pyrethroids."

Receptors on sodium channels act as doorways. Pyrethroids work by propping open the sodium channel. Mosquitoes don't die from the toxin, per se. They die from sodium overdose. With the door jammed wide open, their cells gulp down sodium, which overexcites their nervous system and eventually leads to paralysis and death.

In the last decade, growing resistance in mosquitoes has been detected in many countries. At the molecular level, resistance appears as mutations in the primary receptor in the sodium channel that allow mosquitoes to survive exposure to the . The discovery of the second receptor in the sodium channel, however, opens up more avenues to increase ' effectiveness.

"One of the keys to the success of this research was our cloning of a mosquito for the first time," said Ke Dong, MSU insect toxicologist and neurobiologist and the paper's senior author. "Another lead author of this study, Yoshiko Nomura, dedicated nearly one year to make this happen, which allowed Dr. Du to perform electrophysiological experiments with the clone."

The team then spent nearly two years to discover the new pyrethroid-binding site, she added.

The revelation not only explains much of pyrethroid resistance found in mosquito populations worldwide, but also helps answer why they affect insects but not humans and other mammals. Since this is a growing issue with cockroaches, bedbugs, fleas, potato beetles and other crop pests, the discovery could lead to benefits for the pest-control industry and farming.

"Our finding may ultimately improve global prediction and monitoring of pyrethroid resistance in and other arthropod pests," Dong said. "It could have broad impacts in agriculture and medicine that affect people's lives, especially in developing countries."

Explore further: Scientists find chemical that causes 'kidney' failure in mosquitoes

Related Stories

New insecticide created for mosquitoes

Jul 18, 2007

French scientists have developed an effective insecticide-repellent compound that can be used against mosquitoes resistant to current chemicals.

Scorpion venom -- bad for bugs, good for pesticides

Apr 27, 2011

Fables have long cast scorpions as bad-natured killers of hapless turtles that naively agree to ferry them across rivers. Michigan State University scientists, however, see them in a different light.

Recommended for you

Researchers successfully clone adult human stem cells

4 hours ago

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Researchers develop new model of cellular movement

7 hours ago

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

For resetting circadian rhythms, neural cooperation is key

Apr 17, 2014

Fruit flies are pretty predictable when it comes to scheduling their days, with peaks of activity at dawn and dusk and rest times in between. Now, researchers reporting in the Cell Press journal Cell Reports on April 17th h ...

User comments : 0

More news stories

Plants with dormant seeds give rise to more species

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

LinkedIn membership hits 300 million

The career-focused social network LinkedIn announced Friday it has 300 million members, with more than half the total outside the United States.

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

Sun emits a mid-level solar flare

The sun emitted a mid-level solar flare, peaking at 9:03 a.m. EDT on April 18, 2014, and NASA's Solar Dynamics Observatory captured images of the event. Solar flares are powerful bursts of radiation. Harmful ...