Navigation Links
New findings by UCR scientists hold big promise for fight against mosquito-borne diseases
Date:6/1/2011

RIVERSIDE, Calif. Female mosquitoes are efficient carriers of deadly diseases such as malaria, dengue and yellow fever, resulting each year in several million deaths and hundreds of millions of cases.

To find human hosts to bite and spread disease, these mosquitoes use exhaled carbon dioxide as a vital cue. A disruption of the vital carbon dioxide detection machinery of mosquitoes, which would help control the spread of diseases they transmit, has therefore been a long sought-after goal.

Anandasankar Ray, an assistant professor of entomology at the University of California, Riverside, and colleagues report in the June 2 issue of Nature (cover story) that they have identified in the lab and in semi-field trials in Africa three classes of volatile odor molecules that can severely impair, if not completely disrupt, the mosquitoes' carbon dioxide detection machinery.

The breakthrough research covers three of the deadliest species of mosquitoes: Anopheles gambiae (spreads malaria), Aedes aegypti (spreads dengue and yellow fever), and Culex quinquefasciatus (spreads filariasis and West Nile virus).

The odor molecules that the researchers identified work by affecting the mosquitoes' carbon dioxide receptors, which are located in tiny, antennae-like appendages called maxillary palps close to the mouths of the mosquitoes.

The three classes of the odor molecules are:

  • Inhibitors: Odor molecules, like hexanol and butanal, that inhibit the carbon dioxide receptor in mosquitoes and flies.
  • Imitators: Odor molecules, like 2-butanone, that mimic carbon dioxide and could be used as lures for traps to attract mosquitoes away from humans.
  • Blinders: Odors molecules, like 2,3-butanedione, that cause ultra-prolonged activation of the carbon dioxide sensing neurons, effectively "blinding" the mosquitoes and disabling their carbon dioxide detection machinery for several minutes.

"These chemicals offer powerful advantages as potential tools for reducing mosquito-human contact, and can lead to the development of new generations of insect repellents and lures," said Ray, who led the study. "The identification of such odor molecules which can work even at low concentrations, and are therefore economical could be enormously effective in compromising the ability of mosquitoes to seek humans, thus helping control the spread of mosquito-borne diseases."

Female mosquitoes spread disease by first obtaining a blood meal from an infected person and subsequently finding an uninfected person to bite. Extremely sensitive to minute changes in carbon dioxide concentrations, they can sense carbon dioxide in our breath from long distances. Upon encountering a carbon dioxide plume, the mosquitoes orient and fly upwind, arriving eventually near us.

Most mosquito-trapping devices also use carbon dioxide to attract mosquitoes. But these devices tend to be expensive and bulky, and suffer from the usual difficulties associated with supplying carbon dioxide via gas cylinders, dry ice or propane combustion.

"Odor molecules that mimic carbon dioxide activity, on the other hand, can lead to the development of small and inexpensive lures to trap mosquitoes a great benefit, especially to developing countries," Ray said. "These highly portable, convenient and easily replenishable lures can be used wherever mosquitoes are a menace."

In the case of the "blinder" class of molecules, Ray's group found that even a brief exposure to these odor molecules (presented in a blend of four odors: 2.3-butanedione, 1-hexanol, 1-butanal and 1-pentanal) activated the carbon dioxide-sensitive neurons in mosquitoes for at least five and a half minutes, and evoked such a strong and prolonged response in the neurons that the mosquitoes' responses to subsequent carbon dioxide stimuli were severely reduced for several minutes.

In collaboration with Ring Card, a distinguished professor of entomology at UCR, Ray's lab tested the effectiveness of this blend in wind-tunnels, and found that the flight of the blend-exposed mosquitoes toward sources of carbon dioxide in the wind-tunnels was disrupted.

Subsequently, Ray's lab tested the effectiveness of the blend of odors in a semi-field study performed in Kenya in collaboration with scientists Tom Guda and John Githure at the International Centre of Insect Physiology and Ecology (ICIPE), Kenya.

The research team released Culex quiquefasciatus females in a large enclosed greenhouse that contained two hut-like structures with carbon dioxide-emitting traps placed in each of them. The researchers then included in one of the huts a source of the ultra-prolonged blend in the form of a small fan-driven odor dispenser. They found that only a few mosquitoes entered this hut and made it to the carbon dioxide trap.

"The majority of the mosquitoes were blinded by the blend, and their behavior was disrupted so that they could not detect the carbon dioxide trap," Ray explained. "We observed no such disruption of attractive behavior in mosquitoes in the control hut the one with just the carbon dioxide trap and no blend."


'/>"/>

Contact: Iqbal Pittalwala
iqbal@ucr.edu
951-827-6050
University of California - Riverside
Source:Eurekalert  

Related biology technology :

1. Ceregene Reports New Findings Regarding How Parkinsons Brains Respond to Neurotrophic Factors
2. Microplasmin Meets Primary Endpoint in Second Phase III Trial in VMA, Confirms Positive Findings of First Trial
3. New findings promising for transformation optics, cloaking
4. Findings show promise for nuclear fusion test reactors
5. No New Findings in Atrazine Study Promoted by Discredited Researcher, According to the Hudson Institute Center for Global Food Issues
6. Independent Forensics Company DNalysis Implement Amphora's PatentSafe Solution to Preserve and Secure Findings
7. Promega and SwitchGear Publish Findings from Combined Technologies that Correlate Binding Events and Transcriptional Activity
8. New findings could help hybrid, electric cars keep their cool
9. Helix BioPharma to Present L-DOS47 Analytical Method Development Findings at 2009 AAPS National Biotechnology Conference
10. Innocoll Announces Provisional Findings From Its Three Phase 2 Clinical Trials Investigating CollaRx(R) GENTAMICIN TOPICAL for the Treatment and Prevention of Diabetic Foot Infections
11. Gene Therapy Field Advances With Important Clinical Findings Reported in the New England Journal of Medicine
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New findings by UCR scientists hold big promise for fight against mosquito-borne diseases
(Date:2/10/2016)... Feb. 10, 2016  Matchbook, Inc., a company ... growing biotech companies, announced today the appointment of ... Advisor. Jim brings nearly 25 years of experience ... having spent nearly two decades in executive level ... Procurement at Genzyme and, most recently headed global ...
(Date:2/10/2016)... ... February 10, 2016 , ... HOLLOWAY AMERICA, a leading custom ... Rocky Mountain Chapter 21st Annual Vendor Exhibition on Thursday, February 18, 2016. The ... for its annual event, which will run from 3:00 p.m. - 8:30 p.m. ...
(Date:2/10/2016)... ... February 10, 2016 , ... ... comprehensive training and support program, Sonalink™ remote monitoring. The inaugural launch of this ... Friday, February 5th, connecting Dr. Samuel Peretsman to a HIFU technical expert at ...
(Date:2/10/2016)... ... 10, 2016 , ... Curoverse announced today that the open-source, ... capabilities for managing and processing genomic and health data at petabyte scale. ... and analyzing genomic data,” said Adam Berrey chief executive officer at Curoverse. “Microsoft ...
Breaking Biology Technology:
(Date:2/3/2016)... , Feb. 3, 2016 ... addition of the "Emotion Detection and ... Learning, and Others), Software Tools (Facial Expression, ... End Users,and Regions - Global forecast to ... --> http://www.researchandmarkets.com/research/d8zjcd/emotion_detection ) has announced ...
(Date:2/2/2016)... , Feb. 2, 2016 Technology Enhancements Accelerate Growth ... analysis of the digital and computed radiography markets in ... , and Indonesia (TIM). It ... market size, as well as regional market drivers and ... discusses market penetration and market attractiveness, both for digital ...
(Date:2/1/2016)... 1, 2016  Today, the first day of American ... to develop a first of its kind workplace health ... Watson. In the first application of Watson ... IBM ), and Welltok will create a new offering ... cognitive analytics, delivered on Welltok,s health optimization platform. The ...
Breaking Biology News(10 mins):