Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find how protein allows insects to detect and respond to pheromones

20.01.2005


How do insects smell? Badly, according to a new study, if they lack a certain kind of protein critical to their ability to detect and interpret pheromones – the insect equivalent of "smelling."



Researchers at UT Southwestern Medical Center have discovered how a protein, called an olfactory binding protein, links incoming pheromone signals and specific nerve cells in an insect’s brain, which in turn translate those signals. Pheromones are chemical signals given off by animals that, when detected by others of the same species, mediate a variety of behaviors, such as feeding, mating and colonizing.

The findings not only shed light on insect behavior, but also suggest that olfactory binding proteins may be new targets for synthetic chemicals that could trick insects like mosquitoes into traps or could function as repellents, said Dr. Dean Smith, associate professor of pharmacology at UT Southwestern and senior author on the study. Humans give off signals that attract mosquitoes, the insect responsible for spreading malaria, which kills up to 3 million people each year.


The research, appearing in the Jan. 20 issue of the journal Neuron, is the first to directly link pheromone-induced behavior with the activity of olfactory binding proteins, or OBPs.

The nerve cells, or neurons, in insects responsible for picking up on pheromone signals have been studied for decades, as have pheromones themselves. But the biochemical mechanism by which pheromones and other odorants selectively activate those sensory neurons is poorly understood. "We’ve known about OBPs for 20 years, but until now their function and significance was unclear," said Dr. Smith, who works in the Center for Basic Neuroscience. Olfactory binding proteins are produced by non-neuronal cells and are secreted into the fluid bathing the dendrites, or nerve endings, of olfactory neurons.

Dr. Smith’s research group found that an OBP in fruit flies called LUSH is required for olfactory neurons to smell the pheromone 11-cis vaccenyl acetate, or VA. Mutant flies lacking the gene that codes for the LUSH protein are unable to detect the VA pheromone and do not display the behavior associated with that pheromone, which normally signals the flies to aggregate in groups.

When the VA pheromone contacts a tiny hair on a fly’s antenna, it binds with the LUSH protein. Once bound, the LUSH protein changes its shape so it can fit into a receptor on the surface of a specific olfactory neuron inside the hair, which sends the appropriate behavioral signal to the bug. "Without LUSH as a bridge, this pheromone can’t get its signal to the neuron and the fly doesn’t behave normally," Dr. Smith said. His research group reinstated the correct behavior in the mutant flies by injecting them with the missing lush gene.

In the absence of the pheromone, the researchers found that LUSH still binds to the olfactory neuron, sparking the neuron to fire a small electrical signal called "spontaneous activity." With the pheromone present, and bound to LUSH, the neuron exhibits a large burst of normal electrical activity. In mutants lacking LUSH, however, they found a 400-fold reduction in spontaneous activity, indicating that LUSH is necessary for the neuron to function properly. "This reduction in spontaneous activity was a surprising finding," Dr. Smith said. "Our results indicate that LUSH, and not the pheromone, is what directly activates the chemosensory neurons. It is likely that OBPs in other insects also work this way, although the pheromones are different in different species. We think that OBPs might be new targets for insect control and repellents." Other studies have also linked OBPs to insect behavior. A 2002 fire ant study suggested a role for OBPs in worker ants’ ability to recognize queens and regulate the number of queens in a colony.

The new UT Southwestern findings represent "a major breakthrough in our understanding of what role olfactory binding proteins play in insect pheromone detection," Drs. Leslie B. Vosshall and Marcus C. Stensmyr of The Rockefeller University wrote in a preview article in the same issue of Neuron.

Dr. Smith and his colleagues first identified the lush gene in the fruit fly Drosophila in 1998. They found that mutant flies lacking the gene respond abnormally in the presence of alcohol. Instead of avoiding it, as normal flies do, the mutant flies flocked to alcohol.

Other UT Southwestern researchers involved in the study are lead author Dr. PingXi Xu, a pharmacology postdoctoral researcher, and former research technician Rachel Atkinson. David N.M. Jones from the University of Colorado Health Sciences Center also contributed.

Amanda Siegfried | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>