ABSTRACT
The data generated by current high-throughput assays for chemical toxicity require information to link effects at molecular targets to adverse outcomes in whole animals. In addition, more efficient methods for testing volatile chemicals are needed. Here we begin to address these issues by determining the utility of measuring behavioral responses of Drosophila melanogaster to airborne volatile organic compounds (VOCs) as a potential model system for discovering adverse outcome pathways and as a method to test for toxicity. In these experiments, we measured motor activity in male and female flies to determine concentration-effect functions for three VOCs that differ in their mode of action: toluene, a narcotic; acrolein, an irritant; and vinyl chloride, a hepatocarcinogen. These experiments were conducted in Flyland, an outbred population of flies derived from 40 lines of the Drosophila Genetics Reference Panel (DGRP) (Mackay et al., 2012), in preparation for subsequent experiments with individual lines of the DGRP. Systematic, concentration-related changes in activity were observed with toluene, but not with acrolein; high concentrations of vinyl chloride reduced activity by a small amount. Despite higher activity levels in males than in females under control conditions, the sexes were equally sensitive to toluene. Transient increases in activity at the onset and offset of exposure to toluene and vinyl chloride suggested that the flies detected changes in air quality at concentrations that did not persistently suppress activity. The effects and potency of toluene are consistent with those observed in rodents. The lack of clear concentration-related changes in response to acrolein and vinyl chloride shows limitations of this method is for screening toxicity attributed to VOCs. This abstract does not reflect U.S. EPA policy.
