The effects of low-level, transient exposures to organophosphate pesticides (OPP) and chemically related nerve agents (e.g., sarin, soman, tabun) remain difficult to detect. Because Caenorhabditis elega is relatively resistant to OPP lethality, studies in this nematode provide an opportunity to observe alterations in global gene expression following OPP exposure that cannot be readily observed in less resistant organisms. It may be possible to highlight changes in gene expression that might ...