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ULTRAVIOLET PROTECTIVE COMPOUNDS AS A RESPONSE TO ULTRAVIOLET RADIATION EXPOSURE
Citation:
Hansen, L J. ULTRAVIOLET PROTECTIVE COMPOUNDS AS A RESPONSE TO ULTRAVIOLET RADIATION EXPOSURE. Presented at 13th International Congress on Photobiology, San Francisco, CA, 1-6 July 2000.
Description:
Life on Earth has evolved adaptations to many environmental stresses over the epochs. One consistent stress has been exposure to ultraviolet radiation. In response to UVR organisms have adapted myriad responses; behavioral, morphological and physiological. Behaviorally, some organisms reside in light free habitat, such as caves, while others simply seek shade during high daily irradiance periods. Morphologically, there are protective barriers, such as exoskeletons, scales, feathers and fur, which offer varying degrees of protection. The main components of physiological protection are the accumulation and production of UV protective compounds. These include those compounds that act as screens, such a melanin, scytonemin, and mycosporine-like amino acids, as well as compounds which may act to protect from the detrimental effects of UV, such as carotenoids. While the need for such compounds is almost ubiquitous, the specific compounds and method of acquisition varies greatly among taxa. In a survey of a variety of taxa the occurrence of such compounds following UV exposure is explored. To determine the relative sensitivity of a high elevation amphibian species (Rana muscosa), developing embryos were exposed to four intensities of UV radiation until seven days post-hatching. At the end of the exposure period, surviving tadpoles were examined for variation in pigment patterns and densities. There was a visual difference in the number of iridophores between No UVB and High Ambient UVB treatment surviving individuals. A coral species (Porites porites) was exposed to natural and simulated solar radiation and was then analyzed for variation between treatments in carotenoid concentrations. Exposures of grass shrimp ( Paleomonetes pugio) to artificial UV determined variation in chromatophores attributable to UV and visible light.