TUESDAY, May 13, 2003 (HealthDayNews) -- A University of Florida study offers the first photographic evidence that a protein crucial to vision moves inside eye cells in response to light.
The finding may help explain how people and animals are able to see in a wide range of lighting conditions. Information about this protein's movement may also help scientists better understand diseases such as night blindness or macular degeneration, the leading cause of vision loss in Americans over age 65.
The study was published online in the journal Experimental Eye Research.
The protein is called visual arrestin. It regulates a chemical reaction that's responsible for vision that begins in the retina.
"The movement of arrestins probably impacts how we're able to regulate the light sensitivity of our eyes. If you go from a darkened theatre to bright sunlight, the light intensity can increase by a factor of 10 billion. Not many receptors are capable of dealing with that kind of range, but our eyes can," researcher W. Clay Smith, an assistant professor of ophthalmology, says in a news release.
He and his colleagues examined retinal cells called rods. These rods operate in low-light conditions but don't perceive color. The researchers traced arrestin's movement in rod cells by introducing a gene derived from luminous jellyfish into African clawed frog tadpoles.
That caused the tadpoles' eyes to produce arrestin that glowed bright green when exposed to blue light. That made it easy for the researchers to detect and photograph the arrestin.
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