Entomologists at the University of California, Riverside working on fruit flies in the lab have discovered a novel class of compounds that could pave the way for developing inexpensive and safe mosquito repellents for combating West Nile virus and other deadly tropical diseases.
When fruit flies undergo stress, they emit carbon dioxide (CO2) that serves as a warning to other fruit flies that danger or predators could be nearby. The fruit flies are able to detect the CO2 and escape because their antennae are equipped with specialized neurons that are sensitive to the gas.
But fruits and other important food sources for fruit flies also emit CO2 as a by-product of respiration and ripening. If the innate response of the fruit fly is to avoid CO2, how then does it find its way to these foods?
Anandasankar Ray, an assistant professor in the Department of Entomology, and Stephanie Turner, his graduate student, now provide an answer to the paradox.
They have identified a new class of odorants – chemical compounds with smells – present in ripening fruit that prevent the CO2-sensitive neurons in the antennae from functioning. In particular two odors, hexanol and 2,3- butanedione, are strong inhibitors of the CO2-sensitive neurons in the fruit fly.
The research has strong implications for control of deadly diseases transmitted by Culex mosquitoes such as West Nile virus disease and filariasis, an infectious tropical disease affecting the lymphatic system. Since 1999, nearly 29,000 people in the United States have been reported with West Nile virus disease. Lymphatic filariasis has affected more than 120 million people in the world.
"CO2 emitted in human breath is the main attractant for the Culex mosquito to find people, aiding the transmission of these deadly diseases," Ray said. "In our experiments we identified hexanol, and a related odor, butanal, as strong inhibitors of CO2-sensitive neurons in Culex mosquitoes. These compounds can now be used to guide research in developing novel repellents and masking agents that are economical and environmentally safe methods to block mosquitoes' ability to detect CO2 in our breath, thereby dramatically reducing mosquito-human contact."
Study results appear Aug. 26 in the advance online publication of Nature.
A video, "Combating West Nile Virus and other Tropical Diseases," is available here.
"This is a beautiful study that breaks new ground in the field of olfaction," said John Carlson, the Eugene Higgins Professor of Molecular, Cellular and Developmental Biology at Yale University, who was not involved in the research. "It shows that certain odorants can strongly inhibit the response of receptors that detect CO2. The results suggest some very interesting new strategies for the control of certain insect pests."
Besides showing that inhibitory odors can play an important role in modifying insect behavior, the research paper also illustrates how some of these odors have a long-term effect. Ray and Turner found, for example, that some odors silenced the CO2 neuron in the fruit fly well beyond the period of application.
"To our surprise, we found that exposure to a long-term CO2 response inhibitor can exert a profound and specific effect on the behavior of the insect, even after the inhibitor is no longer in the environment," Ray said. "This means this odorant could potentially be used to keep mosquitoes at bay for longer periods of time, benefiting people in areas where mosquito-transmitted diseases are prevalent."
Ray received his doctoral degree in molecular, cellular and developmental biology from Yale University in 2005. He joined UC Riverside in 2007. His awards include Yale University's John Spangler Nicholas Prize and the Polak Young Investigator Award from the Association of Chemoreception Sciences.
Originally from India, Ray contracted malaria during childhood. When his wife caught dengue fever on a trip to India a few years ago, he decided to intensify his research on mosquito-borne diseases.
Stephanie Turner, the first author of the research paper, received her bachelor's degree in biochemistry from UC Santa Cruz, where she performed research as an undergraduate. She worked for two years in biotechnology before joining the Cell, Molecular and Developmental Biology Graduate Program at UCR.
The research related to this project was conceived, initiated and carried out at UCR over the past one year, and was supported by UCR startup funds. Ray has plans to launch a startup company in the near future to take his basic science research on the odorants from the lab to applications that directly benefit people.
Ray and Turner already have begun work in the lab on mosquitoes that cause malaria and dengue fever. They also are setting up collaborations with a number of scientists from around the globe to do research on various mosquito species and tsetse flies.
The UCR Office of Technology Commercialization has filed a patent application on the discovery.
The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 17,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion. To learn more, visit www.ucr.edu or call (951) UCR-NEWS.
Iqbal Pittalwala | EurekAlert!
Further reports about: > CO2 > CO2-sensitive > Molecular Target > Nile Delta > Riverside > UCR > West Nile virus > carbon dioxide > deadly disease > deadly tropical diseases > food source > fruit flies > fruit fly > mosquito species > mosquito-borne disease > sensitive neurons > synthetic biology > tropical disease > tsetse flies
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy