Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Psst! Coffee drinkers: Fruit flies have something to tell you about caffeine

19.09.2006
In their hunt for genes and proteins that explain how animals discern bitter from sweet, a team of Johns Hopkins researchers began by testing whether mutant fruit flies prefer eating sugar over sugar laced with caffeine. Using a simple behavioral test, the researchers discovered that a single protein missing from the fly-equivalent of our taste buds caused them to ignore caffeine's taste and consume the caffeine as if it were not there.

"No, you won't see jittery Drosophila flitting past your bananas to slurp your morning java anytime soon," says Craig Montell, Ph.D., a professor of biological chemistry in the Institute of Basic Biomedical Sciences at Hopkins. "The bottom line is that our mutant flies willingly drink caffeine-laced liquids and foods because they can't taste its bitterness -- their taste receptor cells don't detect it."

The Hopkins flies, genetically mutated to lack a certain taste receptor protein, have been the focus of studies to sort out how animals taste and why we like the taste of some things but are turned off by the taste of others.

By color-coding sweet and bitter substances eaten by fruit flies and examining the coloring that shows up in their translucent bellies, the Hopkins team hoped to learn whether flies missing a specific "taste-receptor" protein changed their taste preferences.

... more about:
»Gr66a »Montell »caffeine »flies »receptor

"Normally," Montell explains, "when given the choice between sweet and bitter substances, flies avoid caffeine and other bitter-tasting chemicals. But flies missing this particular taste-receptor protein, called Gr66a, consume caffeine because their taste-receptor cells don't fire in response to it."

The discovery, which is the first ever example of a protein required for both caffeine tasting and caffeine-induced behavior, will be published Sept. 19 in Current Biology.

For the study, Montell and his colleagues kept 50 fruit flies away from food overnight and for breakfast gave the starved flies 90 minutes to eat as much as they wanted of either or both of two concoctions: a blue-colored mixture of sugar and agar and a red-colored mixture of caffeine, sugar and agar. The researchers then flipped the flies onto their backs and looked at the color of their bellies to see what they ate - blue indicating a preference for eating sugar, red indicating a preference for bitter caffeine, and purple indicating no preference.

Flies missing the critical taste receptor protein Gr66a consumed the bitter caffeine solution to the same extent as the sugar-only solution. Montell and colleagues conclude that Gr66a is crucial for the normal caffeine avoidance behavior and without it, flies are seemingly indifferent to the bitter taste.

The researchers went on to examine whether this indifference to bitter was due to the taste nerves on the fly's "tongue" or some malfunction in the fly's brain. Chemical stimulants trigger taste receptor cells to send an electrical current to the brain where the information is processed and often leads to a change in behavior, such as the decision to eat or avoid.

With fine tools, the research team recorded electrical currents in those cells known to contain the Gr66a caffeine taste receptor in the fly's equivalent of the taste buds - dubbed the taste bristles.

Applying sugar to the taste bristles of normal flies, or to mutant flies missing the Gr66a protein, causes the neurons to produce electrical current "spikes" at a frequency of about 20 spikes per second. Other bitter compounds like quinine generated electrical current spikes at about the same frequency in the mutants.

Only flies missing the Gr66a taste receptor protein were unable to generate any current spikes when given caffeine. "This is a clear demonstration that Gr66a is functioning in the taste receptor cells and is not a 'general sensor' for bitter compounds, but is required more specifically for the caffeine response," says Montell.

"This indicates that flies have different receptors for the response to other types of bitter compounds," he says.

"We also tested whether the flies avoided the related bitter compounds found in tea and cocoa -- chocolate -- and found that Gr66a also is required for the response to the compound in tea, but not for the one in chocolate," he says.

Fruit flies often are used as experimental organisms because they grow quickly and are easy to manipulate genetically. Now that Montell and his colleagues have a mutant fly that is unable to taste caffeine, they hope to further examine the other genes and molecules involved in the caffeine response and better understand the biochemistry behind caffeine-induced behavior in other organisms, namely humans.

Audrey Huang | EurekAlert!
Further information:
http://www.hopkinsmedicine.org/cmontell/
http://www.hopkinsmedicine.org/ibbs/index.html

Further reports about: Gr66a Montell caffeine flies receptor

More articles from Life Sciences:

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

nachricht Chlamydia: How bacteria take over control
28.03.2017 | Julius-Maximilians-Universität Würzburg

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

Researchers create artificial materials atom-by-atom

28.03.2017 | Physics and Astronomy

Researchers show p300 protein may suppress leukemia in MDS patients

28.03.2017 | Health and Medicine

Asian dust providing key nutrients for California's giant sequoias

28.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>