FIGURE 1.

(A) dat-1 promoter is more efficient in silencing GFP expression in the dopaminergic neurons than the cat-2 promoter. Using a cell-specific RNAi technique (Esposito et al., 2007), the two promoters pcat-2 and pdat-1 were employed to silence the gfp gene specifically expressed in the dopaminergic neurons. Animals carry an integrated transgene for the expression of GFP only in dopaminergic neurons. The percentage of visible dopaminergic neurons expressing GFP over the number of neurons expected (eight per animal) is reported. pdat-1 promoter was significantly more efficient (^∗p < 0.001, control vs pdat-1::gfp sas) in silencing the GFP expression than pcat-2 (^#p > 0.01, control vs pcat-2::gfp sas). n is the number of animals observed. Statistical analysis was performed using one-way ANOVA with Bonferroni post-test. (B) cat-2 silencing through the dat-1 promoter is sufficient to mimic a cat-2 dependent behavior. Similar to cat-2(e1112) null mutants (Sawin et al., 2000), cat-2 silenced animals (pdat-1::cat-2 sas) do not slowdown in presence of food. On the other hand, wild type, controls (non-transgenic siblings) and GFP silenced (pdat-1::gfp sas) animals reduce their locomotion rate when encounter bacteria. The locomotion rate for 20 s off and on food is reported as percent of slowing (% Slowing) calculated by dividing the difference between locomotion rates on and off food by the locomotion rate off food. n represents the number of animals tested. Kruskal–Wallis non-parametric with Dunn’s multiple comparison post-test shows significant difference between wild type animals on food vs cat-2(e1112) on food (^§ p < 0.001) and pdat-1::gfp sas on food vs pdat-1::cat-2 sas on food (°p < 0.001).