Fig. 3.

Dose–response for male and female attraction to major P. redivivus ascarosides. P. redivivus males and females were separately scored for their response to areas conditioned with different amounts of synthesized ascarosides (10⁰–10⁵ fmol). Their occupancy in the area containing the ascaroside was compared with occupancy in the control region (containing the same concentration of ethanol in water as the ascaroside dilution for each trial) for the duration of 20 min. Experiments in which males or females spent significantly more time in the control region have a negative index score, indicating avoidance of the ascaroside. Experiments in which males or female spent significantly more time in the ascaroside region have a positive index score, indicating attraction to the ascaroside. Error bars are SD. Statistical significance for each value was calculated compared with response to ddH₂O when present in both scoring regions, which was shown first in each set. (One-factor ANOVA followed by Dunnett’s posttest; *P < 0.05, **P < 0.01.)