Evaluation of genotoxic effects induced by UV radiation in Caiman latirostris: Progress report.

SCHAUMBURG, G.; G.L. POLETTA AND A. IMHOF.

Santa Cruz de la Sierra, Bolivia

Congreso; 19th Working Meeting of the Crocodile Specialist Group, IUCN-SSC; 2008

CSG/IUCN/SSC

Ultraviolet (UV) radiation is a component of the solar energy emission spectrum. The ecological importance of UV light has been extensively studied during many years, on account of stratospheric ozone depletion in certain areas of the planet, which has led to an excessive UV radiation over ecosystems. Overexposure of organisms to UV radiation may produce different biological effects as a result of photochemical absortion by significant molecules such as proteins and nucleic acids. Among them, DNA damage induced by UV-A/UV-B exposure, which included mainly thymine dimers and chromosomal fragmentation, are considered of prime importance. The aim of this study is to evaluate genotoxic effects of UV-A and UV-B radiation in juvenile Caiman latirostris, using the Micronucleus (MN) test as a biomarker. Seventy two juvenile caimans were reared during 3 ½ months under one of three conditions: 24 hours darkness and exposure of 8 or 16 daily hours of artificial  UV-A/B light, respectively. Blood samples were collected at the beginning and at the end of the experiment to determine the incidence of UV/A-B radiation on erythrocyte MN frequences and evaluate differences between treatments. Up to the moment, 75 % of the samples have been analysed.