On the role of baculovirus photolyases in DNA repair upon UV damage of occlusion bodies

Abstract: The use of baculoviruses in insect biocontrol is hampered by their sensitivity toultraviolet (UV) light. This irradiation induces cyclobutane pyrimidine dimers (CPDs) in DNA.CPD-photolyases repair CPDs using visible light. Plusiine baculoviruses encode photolyases,which could potentially repair UV-damage prior to infection of larvae. Whether the photolyasesencoded by Chrysodeixis chalcites nucleoplyhedrovirus are involved in UV damage repair wastested by infecting larvae with UV-irradiated viral occlusion bodies (OBs) that were subsequentlytreated with visible light or kept in the dark. The observed mortality was the same for bothtreatments. We postulate that photolyases are not active as DNA repair enzymes in OBs, but mayplay a role in other aspects of baculovirus pathogenesis.