Figure 2

Effect of selected candidate genes on arsenite-induced gene expression and arsenite resistance. (A) The effect of selected RNAi targeting of genes required for resistance to ionizing radiation (IR) [18] or the extended lifespan of daf-2 mutant [19] on arsenite resistance. (B) Twelve of the most robust regulators (Table 1) on arsenite-induced expression of gcs-1 (upper panel) and gst-7 (lower panel) and (C) arsenite resistance. In (A) and (C), comparisons are shown between the mean survival time following exposure of wild-type animals treated with the indicated RNAi or empty vector control to 7.5 mM arsenite. Mean survival times were calculated relative to control based on data obtained from a minimum of three separate experiments (see Additional file 2: Figure S4 for representative experiments). Error bars represent the standard error of the mean. Statistically significant differences between the survival of RNAi-treated and control animals (*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001) were identified by Cox's regression analysis of the data obtained in all the experiments. In (B), comparisons are shown between the levels of gcs-1 (upper panel) or gst-7 (lower panel) mRNA in wild-type animals treated with the indicated RNAi or empty vector control following exposure to 5 mM arsenite for 30 min. Mean RNA levels relative to control were calculated from a minimum of three separate experiments. Error bars represent the standard error of the mean. Statistically significant differences between the gcs-1 and/or gst-7 mRNA levels in RNAi-treated and control animals (Student's T test) are indicated (*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001). IR, ionizing radiation; RNAi, RNA interference.