Hypersensitivity of a Urate-null Strain of Drosophila melanogaster to the Toxic Effects of Environmental Cigarette Smoke

Epidemiological evidence indicates that cigarette smoke is harmful to human health. Mainstream cigarette smoke has already been demonstrated to induce tissue and cellular damage in animal models. In the present study, we examined the toxicity of environmental cigarette smoke (ECS) by exposing Drosophila melanogaster larvae from urate-null and wild-type strains to ECS for 3 or 6 h at the third instar stage. We then determined survival to adulthood and the fecundity of adult females that survived larval ECS exposure. The survival of the urate-null strain, but not the wild-type strain, decreased significantly in an exposure-dependent manner. Moreover, the fecundity of treated urate-null, but not wild-type, females decreased significantly relative to the control level, irrespective of mating partner exposure to ECS at the larvae stage. These results demonstrate the killing effect and reproductive toxicity of ECS on urate-null larvae of Drosophila. Since the urate-null strain is known to be sensitive to oxidative agents, we propose that the main cause of the observed toxic effects of ECS is oxidative stress. Key words: environmental cigarette smoke, urate-null strain, survival, Drosophila, fecundity.