Figure 1. The PDF-1 pathway is required for the male-specific expression of daf-7 in the ASJ neurons and its effects on male mate-searching behavior.

(A) PDF-1 signaling activates cAMP production and regulates both roaming behavior and male mate-searching behavior in C. elegans. (B–C) Maximum fluorescence values of pdaf-7::gfp in the ASJ (B) and ASI (C) neurons of adult male animals. ***p<0.001 as determined by ordinary one-way ANOVA followed by Dunnett’s multiple comparisons test. Error bars represent standard deviation (SD). ns, not significant. n = 15 animals for all genotypes. (D) Probability of leaving values for epistasis experiment between daf-7(ok3125) and a PDF-1 overexpressing line. Values plotted are the mean +SEM for three independent experiments. Significance determined by unpaired t-test with Welch’s correction. ns, not significant. n = 60 total animals for all genotypes except the daf-7(ok3125); qdEx149 strain where n = 48. (E) Maximum fluorescence values of pdaf-7::gfp in the ASJ neurons of hermaphrodites after 16 hr on P. aeruginosa. Significance determined by ordinary one-way ANOVA followed by Dunnett’s multiple comparisons test. Error bars represent SD. ns, not significant. n = 15 animals for all genotypes. (F) Lawn occupancy of animals on P. aeruginosa after 16 hr. ***p<0.001 as determined by ordinary one-way ANOVA followed by Dunnett’s multiple comparisons test. Values plotted indicate the mean + SD for three replicates. Number of animals assayed are as follows: WT (n = 89), daf-7 (n = 66), pdf-1 (n = 117), pdfr-1 (n = 105).

Figure 1—figure supplement 1. The PDF-1 pathway regulates mate-searching behavior via male-specific modulation of daf-7 expression in ASJ and through parallel mechanisms.

(A) Representative mate-searching data curves for WT (dashed black), daf-7 mutant (light blue), pdf-1(+) transgenics (dark blue), and the daf-7; pdf-1(+) double (light blue dashed) males. n = 20 animals for each curve shown except for daf-7;pdf-1(+) where n = 16 animals. (B) Representative mate searching data curves for WT (dashed black), pdf-1 mutant (orange), and pdf-1 mutant males with daf-7 overexpressed from ASJ (red). n = 20 for all genotypes.

Figure 1—figure supplement 2. PDF-1 pathway mutant males can upregulate daf-7 expression in ASJ in response to P. aeruginosa exposure and show intact pathogen avoidance behavior.

(A) Maximum fluorescence values of pdaf-7::gfp expression in ASJ for males exposed to E. coli (black) or P. aeruginosa (green) for 16 hr. ***p<0.001, *p<0.05 as determined by unpaired t-tests with Welch’s correction. n = 15 animals for all genotypes and conditions. (B) Lawn occupancy of animals on P. aeruginosa after 16 hr. Significance as determined by ordinary one-way ANOVA followed by Dunnett’s multiple comparisons test. ns, not significant. Values plotted indicate the mean + SEM for three independent experiments. 30 animals were assayed per experiment (n = 90 across all experiments for all genotypes).