Effect of radiation-induced oxidative stress on mating success of Caribbean fruit flies

Oxidative stress is a pervasive factor that can influence many aspects of organismal life histories, including reproduction. Sterile Insect Technique (SIT) is a successful autocidal biological control method that uses ionizing radiation to sterilize insects. Irradiation effectively sterilizes insects by causing dominant lethal double stranded DNA breaks, but irradiation also has side effects including substantial oxidative stress that reduces the mating success of sterile males. In this study, we hypothesize that enhancing antioxidant capacity will reduce oxidative stress and increase male mating success. By overexpressing a key antioxidant enzyme, the mitochondrial superoxide dismutase (MnSOD), in Caribbean fruit flies, we can test whether increasing antioxidant capacity will decrease oxidative stress and increase mating success after irradiation sterilization. We successfully produced seven transgenic lines that overexpress SOD and showed superoxide dismutase enzymatic activity up to 130% more than wild-type flies. Preliminary results suggest that some SOD lines exposed to irradiation had greater mating success than irradiated wild type flies. Future investigations will evaluate whether overexpression of SOD is correlated with decreased oxidative damage to DNA, lipids, and proteins. The results from this research can both help us to better understand the evolution of female mate choice and improve insect pest management techniques, such as the SIT.