Fig. 4. Number of thrashes per minute in WT and skn-1(ok2315) untreated and GEE-pretreated worms 0 hours (A and B) and 24 hours (C and D) post 6-hour MeHg exposure. A thrash was defined as a change in the direction of bending at the middle of the body and was assessed in worms individually placed in a drop of M9 with a stereomicroscope. MeHg induced a dose-dependent decrease in the number of thrashes immediately post 6-hour exposure, and post 24 hours, worms partially recovered movements. (#) Represents a significant difference between control and metal exposed worms by two-way ANOVA followed by Bonferroni's multiple comparison test (p < 0.05) and (*) represents a significant difference between untreated and GEE-pre treated worms by two-way ANOVA followed by Bonferroni's multiple comparison test (p < 0.05). Data are expressed as means ± SEM, n = 4.