Superoxide dismutase down-regulation and the oxidative stress is required to initiate pupation in Bombyx mori

Abstract

AbstractPerhaps, oxidative stress progresses pupation in some Lepidopteran insects; however, the reasons for this remain obscure. In our previous study, we clarifiedBombyx moriSOD1 (BmSOD1) andB. moriSOD2 (BmSOD2) proteins respond in common to ultraviolet irradiation (UV) oxidative stress and metamorphosis. This result strongly suggested pupation initiates by oxidative stress and might mediate by down-regulation of expression of BmSOD1 and BmSOD2 proteins. Thus, we examined about these relationships inB. moriin this study. In the microarray data reanalysis, we found the Notch signaling pathways as the common pathways in pupation and UV oxidative stress inB. mori. Also, we showed a molting hormone, 20-hydroxyecdysone, leads not only generation of superoxide but also downregulation of the expression of BmSOD proteins during pupation inB. mori. Our findings can contribute to a deeper understanding of how biological defense systems work against environmental oxidative stress.