DNA repair by photolyases has classically been viewed as a light-dependent process, restricted to the reversal of UV-induced pyrimidine dimers. A recent study published in Nature Communications overturns this paradigm by showing that CPD photolyase in the blind cavefish Phreatichthys andruzzii is still involved in DNA repair function in complete darkness. Using comparative models of surface-dwelling and cave-dwelling fish, the authors demonstrate that CPD photolyase not only mediates photoreactivation under light but also protects against oxidative DNA lesions in the absence of light, explaining its remarkable evolutionary conservation. A recent cavefish study overturns the classic view of photolyases as light-dependent enzymes. Research shows CPD photolyase repairs oxidative DNA damage in darkness, revealing a dual function that explains its conservation in cave species
Hong et al. (Fri,) studied this question.