Ultraviolet radiation-induced genotoxic effects in the broad-snouted caiman, Caiman latirostris.

Ultraviolet radiation (UVR) has many positive effects, but overexposure of organisms can generate alterations in DNA, either directly or indirectly, inducing mutagenic and cytotoxic lesions. The aim of this study was to evaluate the genotoxic effects of UVA-B/visible light in the broad-snouted caiman (Caiman latirostris), using the micronucleus (MN) test as a biomarker. Seventy two juvenile caimans, approximately 5 months old, were maintained for during 3 months under total darkness, or under 8 or 16h of daily exposure to artificial UV/visible light. MN test was applied before and after the experiment and the difference in MN frequencies was determined. Our results indicate significant increases in MN frequency with all treatments, compared to the basal (before experiment) values. Animals exposed to UV radiation showed a greater increase in MN frequency, compared to the animals exposed to total darkness (TD) treatment. These results provide information about the possible harmful effects generated by sub-chronic exposure to UVR in zoos, reptile hobbyist and breeding programs, as well as the deleterious consequences of increased UV environmental impact on wild species such as the broad-snouted caiman.