The findings, they write, may also have implications for the regulating of olfactory receptors, which are responsible for the detection of smells, because both types of receptors belong to the same protein family.
Biologists have previously found that most sensory systems follow the “one receptor molecule per receptor cell” rule. For example, photoreceptors in the fly eye and human cones—our color-sensitive photoreceptors—each express only one rhodopsin, a pigment that is sensitive to only one color. Rhodopsins are G-coupled protein receptors, a class of ancient signaling molecules that mediate not just vision, but also the sense of smell and other physiological processes.
In the PloS Biology study, the NYU researchers examined the eye of the fruit fly Drosophila. Fruit flies can be analyzed and manipulated in exquisite details by biologists and serve as a powerful model system to understand biological processes such as vision. In each of the estimated 800 individual facets that make up the fly eye, there are eight photoreceptors (R1–R8). Six of these mediate broad-spectrum detection of motion (R1–R6) and two mediate color vision (R7 and R8) and are similar to the human cone photoreceptors.
The NYU researchers, headed by Biology Professor Claude Desplan, sought to understand the mechanisms that regulate mutual exclusion of rhodopsin photoreceptor genes in the fly retina, which is poorly understood. Their results revealed a new class of photoreceptors that violates the one rhodopsin–one photoreceptor rule. This new class, located in the dorsal third of the eye, co-expresses two ultraviolet (UV)-sensitive rhodopsins (rh3 and rh4) in R7, while maintaining discrimination between green and blue rhodopsins in R8.
The NYU researchers found that this co-expression depends on a group of genes—the so-called Iroquois Complex genes—that are known to specify the dorsal side of the eye. These genes are necessary and sufficient to allow the two UV-sensitive rhodopsins to be expressed in the same R7 cell. The purpose of this co-expression of UV-sensitive pigments in a specialized part of the dorsal retina is likely to allow the flies to better orient to the sun for navigation: Flies, like bees, where this has been well documented, can discriminate between the solar side of the landscape, which has fewer radiations in the UV, and the opposite side (anti-solar), which is very UV-rich.
James Devitt | EurekAlert!
Microscope measures muscle weakness
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Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
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Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
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Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
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On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
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