Figure 1. PDF-1 neuropeptide signaling stimulates mate searching.

(a) Genomic and protein domain structures of pdfr-1. (Top) Exons (black boxes) and introns (lines) of the pdfr-1 locus; (bottom) extracellular (red), 7 trans-membrane domains (black) and intracellular (blue) regions are shown. The changes in codon and amino acid produced by the bx142 mutation are indicated.

(b) Graph shows P_L (probability of leaving food) values of wild type (wt), pdfr-1 (bx142) and (tm4457) mutants and mutants in the PDFR-1 ligands pdf-1(tm1996) and pdf-2(tm4393). The pdfr-1(tm4457) allele fails to complement bx142 indicating that the two mutations affect the same locus. The fosmid wrm0629dH07 contains the pdfr-1 locus. Error bars indicate SEM. n indicates total number of animals tested; (exp) indicates the number of independent population-based experiments. Maximum likelihood statistical analysis was used to compare P_L values, ***p<0.001, ns: no statistically significant difference (p≥0.05).

(c) Graphs show the frequency of reversals and high angle turns (Ω turns) performed by wt and pdfr-1(bx142) mutant males during 5 minutes. Locomotion was observed on food and at two different time points off food: 1 minute after removal from food and 30 minutes after removal from food. n indicates total number of animals tested. Error bars indicate SEM. Statistical analysis was performed using Mann-Whitney test, ***p<0.001.

(d) Graphs show the rate at which wild-type (wt) and pdfr-1(bx142) males travel 3.5 cm, from the starting point at the center of the plate within a food patch to the scoring distance 1 cm away from the edge of the assay plate. This was calculated as in the leaving assay, as P_L values (probability of reaching the scoring distance). Error bars indicate SEM. n indicates total number of animals tested; (exp) indicates the number of independent population-based experiments. Maximum likelihood statistical analysis was used to compare P_L values (probability of reaching the scoring distance), ***p<0.001, ns: no statistically significant difference (p≥0.05).

(e) Graph shows P_L values of wild-type and pdfr-1(bx142) mutant males and wild-type hermaphrodites with or without the pdf-1 genomic overexpression (pdf-1 OE) transgene. npr-1(n1353) mutant males display rates of mate-searching behavior similar to wild-type males. Error bars indicate SEM; n indicates total number of animals tested; (exp) indicates the number of independent population-based experiments. Maximum likelihood statistical analysis was used to compare P_L values, ***p<0.001, ns: no statistically significant difference (p≥0.05).