According to researchers at the Monell Center, fruit flies are more like humans in their responses to many sweet tastes than are almost any other species.
The diverse range of molecules that humans experience as sweet do not necessarily taste sweet to other species. For example, aspartame, a sweetener used by humans, does not taste sweet to rats and mice.
However, fruit flies respond positively to most sweeteners preferred by humans, including sweeteners not perceived as sweet by some species of monkeys.
The findings, published in the current issue of the journal Chemical Senses, demonstrate the critical role of environment in shaping the genetic basis of taste preferences and feeding behavior.
“Humans and flies have similar taste responses because they share similar environments and ecological niches, not because their sweet receptors are similar genetically,” notes senior author Paul A.S. Breslin, PhD, a Monell sensory geneticist. “Both are African species, both are omnivorous, and both historically are primarily fruit eaters.”
To compare how molecular structure is related to sweet taste perception in humans and flies, the Monell researchers evaluated how fruit flies respond to 21 nutritive and nonnutritive compounds of varying molecular structure, all of which taste sweet to humans.
Breslin and lead author Beth Gordesky-Gold, PhD, used two behavioral tests to evaluate the flies’ responses to the various sweeteners.
The taste reactivity test measures whether a fly extends its feeding tube, or ‘proboscis,’ to consume a given sweetener. In addition, a two-choice preference test evaluates the flies’ responses to a sweetener by measuring whether they consume it in preference to a control solution (usually water).
The Monell researchers found that fruit flies and humans both respond positively to the same broad range of sweet-tasting molecules.
“The similarity between human and fly responses to sweeteners is astounding, especially in light of the differences in their taste receptors,” notes Gordesky-Gold, a Drosophila (fruit fly) geneticist at Monell.
Sweet receptors belong to a large family of receptors known as G-protein coupled receptors (GPCRs), which are involved in biological processes throughout the body. Human and fly sweet taste GPCRs are presumed to have markedly different structures, an assumption that is based on differences in the genes that code for them.
Since substances will only taste sweet if they are able to bind to and activate a receptor, these two structurally different types of sweet receptors must have similar ‘binding regions’ that fit the same range of molecular shapes.
“That genes could be so divergent in sequence and so similar in physiology and function is truly striking,” says Breslin. “This is a wonderful example of convergent evolution in perceptual behavior, where evolution has taken two different routes to address pressures imposed by shared environment and nutrition.”
Future work will be directed towards modeling how these two structurally different sweet receptors could have highly overlapping sweetener affinities. Such knowledge will increase understanding of how molecules bind to GPCRs, which are targets for many pharmaceutical drugs.
Leslie Stein | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences