Antioxidants are natural food ingredients that protect cells from harmful influences. Their main task is to neutralize so-called “free radicals” which are produced in the process of oxidation and which are responsible for cell degeneration.
Scientists at the Max Planck Institute for Chemical Ecology in Jena, Germany, and the University of Lund, Sweden, now show that vinegar flies are able to detect these protective substances by using olfactory cues. Odors that are exclusively derived from antioxidants attract flies, increase feeding behavior and trigger oviposition in female flies.
Hany Dweck is stimulating olfactory sensory neurons in fruit flies with different odors using the single sensillum recording (SSR) technique.
Hydroxycinnamic acids are secondary plant metabolites and important dietary antioxidants. For animals as well as humans, antioxidants are essential components of a healthy diet, because they protect the cells and boost the immune system. Notably, they prevent the emergence of too many free radicals, mostly oxygen compounds, and therefore a metabolic condition, which is generally called oxidative stress. If an organism suffers from oxidative stress, free radicals attack its cells and weaken its immune system. In fruit flies, oxidative stress is induced by immune responses to toxins produced by pathogens in the food.
Hydroxycinnamic acids are found in high amounts in fruit. Since fruit is the preferred breeding substrate of fruit flies, scientists in the Department of Evolutionary Neuroethology at the Max-Planck-Institute for Chemical Ecology in Jena, Germany, took a closer look at these substances and their possible effect on the flies.
Fruit flies are not able to smell hydroxycinnamic acids directly. However, yeasts metabolize the antioxidants and produce ethylphenols. These volatile substances activate targeted olfactory neurons housed on the maxillary palps of the fruit flies, which express the odorant receptor Or71a. Interestingly, fly larvae which are also attracted by yeasts enriched with hydroxycinnamic acids using ethylphenols as olfactory cues, employ another odorant receptor for binding ethylphenols: Or94b, which is exclusively found in larvae, and which is co-expressed with Or94a, a receptor binding a general yeast odor.
Because flies cannot smell the antioxidants directly, ethylphenols provide reliable cues for the presence of these protective compounds in the food. The perception of these odorant signals has a direct impact of the flies’ behavior: They are attracted by the odor sources, show increased feeding behavior and choose oviposition sites where ethylphenols indicate that antioxidants are present in the breeding substrate.
"This form of olfactory proxy detection is not only a phenomenon in insects. It has also been shown in humans, that odors that we perceive as pleasant or appetizing, are in fact derived from important and healthy nutrients, such as essential amino acids, fatty acids and vitamins," Marcus Stensmyr explains. The scientist, who carried out the studies in the Department of Evolutionary Neuroethology together with his colleagues, has recently moved to a position as senior lecturer at the University of Lund.
These findings demonstrate a further example of an individual neuronal pathway, which has a profound effect on the flies: from the odorant signal to olfactory neurons and dedicated odorant receptors to behavior (see also our press release "A Direct Line through the Brain to Avoid Rotten Food – A Full STOP Signal for Drosophila − Odor activation of a dedicated neural pathway by geosmin, an odor produced by toxic microorganisms, activates a hard-wired avoidance response in the fly": http://www.ice.mpg.de/ext/971.html, December 7, 2012).
The ethylphenol pathway as an olfactory proxy detection of dietary antioxidants shows yet another facet of the complex odor-guided behavior in fruit flies. The scientists will now try to identify further neural pathways involved in the detection of essential nutrients, which ultimately trigger the flies’ behavior. [AO]
Dweck, H., Ebrahim, S. A. M., Farhan, A., Hansson, B. S., Stensmyr, M. C. (2015). Olfactory proxy detection of dietary antioxidants in Drosophila. Current Biology, DOI: 10.1016/j.cub.2014.11.062
Prof. Dr. Bill S. Hansson, Max Planck Institute for Chemical Ecology, firstname.lastname@example.org
Dr. Marcus C. Stensmyr, Department of Biology, Lund University, email@example.com
Kontakt und Bildanfragen
Angela Overmeyer M.A., Max-Planck-Institut für chemische Ökologie, Hans-Knöll-Str. 8, 07743 Jena, +49 3641 57-2110, E-Mail firstname.lastname@example.org
Download von hochaufgelösten Fotos über http://www.ice.mpg.de/ext/735.html
Angela Overmeyer | Max-Planck-Institut für chemische Ökologie
Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University
Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles
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...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Physics and Astronomy
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering