DNA Repair Activity and Resistance to Solar UV-B Radiation in Eggs of the Red-legged Frog

We assessed DNA repair and resistance to solar radiation in eggs of the red-legged frog (Rana aurora) , a species whose populations appear to be in decline. Specifically, we measured the activity of photoreactivating enzyme, photolyase, in R. aurora oocytes. In some species photoreactivation is the most important mechanism for repair of UV-damaged DNA. We also compared the hatching success of R. aurora eggs subjected to ambient levels of UV-B radiation with those shielded from UV-B radiation. We found photolyase levels in R. aurora to be relatively high when compared with other amphibians and hatching success to be unaffected by UV-B radiation. We suggest that UV-B radiation is an unlikely cause for declining populations of red-legged frogs.