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 Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>