Indexed on: 01 Oct '10Published on: 01 Oct '10Published in: Environmental Microbiology Reports
The SOS response is a global regulatory network for repairing DNA damage induced by various environmental stresses such as UV irradiation. The Escherichia coli SOS response has been extensively studied. However, there are no reports on the SOS response in Vibrio parahaemolyticus. In this study, we examined the SOS response in V. parahaemolyticus and compared the differential expression of genes induced by UVC and UVA irradiation. In UVC-exposed wild-type cells, expression of several DNA repair genes was increased. However, expression of these genes was not increased in ΔrecA or lexA mutants. Cell filamentation was observed in wild-type cells, but not in ΔrecA and lexA mutant cells. Sensitivity to UVC was significantly increased in ΔrecA, lexA mutant and Δlon strains compared with wild type. In the case of UVA irradiation, LexA-controlled DNA repair genes were minimally induced and cell filamentation was not observed. Sensitivity to UVA was the same in the mutant and wild-type strains. These findings suggest that there is a RecA-LexA-mediated SOS response in V. parahaemolyticus, and that this response is important to UVC tolerance but does not contribute to UVA tolerance.