DEET has been the gold standard of insect repellents for more than six decades, and now researchers led by a University of California, Davis, scientist have discovered the exact odorant receptor that repels them.
They also have identified a plant defensive compound that might mimic DEET, a discovery that could pave the way for better and more affordable insect repellents. Findings from the study appear in the journal Proceedings of the National Academy of Sciences.
More than 200 million people worldwide use DEET, developed by scientists at the U.S. Department of Agriculture and patented by the U.S. Army in 1946.
“Mosquitoes are considered the most deadly animals on the planet, but unfortunately, not everyone who needs this repellent can afford to use it, and not all who can afford it can use it due to its undesirable properties such as an unpleasant odor,” said lead author Professor Walter Leal of the Department of Molecular and Cellular Biology.
“Vector-borne diseases are major health problems for travelers and people living in endemic regions,” Leal said. “Among the most notorious vectors are mosquitoes that transmit the protozoan parasites causing malaria and viruses that cause infections, such as dengue, yellow fever, chikungunya and encephalitis.”
Mosquitoes detect scents with olfactory receptors on their antennae. The researchers examined two families of olfactory receptors of the southern house mosquito, Culex quinquefasciatus, which transmits diseases such as West Nile virus.
One receptor group, “ionotropic receptors,” normally detects acids, bases and other water-soluble compounds. The researchers discovered, however, that a receptor from the odorant receptor group is directly activated by DEET.
They also detected a link between DEET and the compound methyl jasmonate, suggesting that DEET might work by mimicking a defensive chemical found in plants.
Dan Strickman, senior program officer for Vector Control at the Bill and Melinda Gates Foundation’s Global Health Program, said, “We are at a very exciting time for research on insect repellents.” (The Gates Foundation was not involved in the study.)
“For decades, the field concentrated on screening compounds for activity, with little or no understanding of how chemicals interacted with mosquitoes to discourage biting. Use of modern techniques that combine molecular biology, biochemistry and physiology has generated evidence on how mosquitoes perceive odors,” Strickman said.
Other researchers on the team were project scientist Pingxi Xu, postdoctoral scholar Young-Moo Choo, and agricultural and environmental chemistry graduate student Alyssa De La Rosa.
Mosquito researcher Anthony Cornel, an associate professor with the UC Davis Department of Entomology and Nematology and based at the Kearney Agricultural Research and Extension Center, Parlier, provided mosquitoes that allowed the Leal lab to duplicate his mosquito colony at UC Davis. Richard Benton of the University of Lausanne, Switzerland, shared his flies, Drosophila plasmids, also part of the research.
The work was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.
For more about this study, see the Department of Entomology and Nematology website at: http://entomology.ucdavis.edu/.
UC Davis is a global community of individuals united to better humanity and our natural world while seeking solutions to some of our most pressing challenges. Located near the California state capital, UC Davis has more than 34,000 students, and the full-time equivalent of 4,100 faculty and other academics and 17,400 staff. The campus has an annual research budget of over $750 million, a comprehensive health system and about two dozen specialized research centers. The university offers interdisciplinary graduate study and 99 undergraduate majors in four colleges and six professional schools.
Pat Bailey | Eurek Alert!
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy