Fig. 5

Definition of aggression and pursuit index and comparison of fly pair distance, aggression index and pursuit index during 30-min experiment time across different genotypes. a. Illustration of aggression index and pursuit index definitions based on view angles of the fly pair. Each index is derived from distance measurements between paired body landmarks of two flies, then normalized by body part length. f1, f2: front parts and r1, r2: rear parts of selected two body parts from the two flies, cr2: cross of fly 2 in the cross view representation, d: Euclidean distance of two tracked body parts. Left: aggression index when both flies are visible in top or side view. Its value ranges from –1 to 1 approximately. The higher value indicates that the two flies tend to be in head-to-head position during the experiment. Right: pursuit index when both flies are in top or side view. Its value ranges from 0 to 1 approximately. The higher value indicates that two flies tend to be in chasing or following body position during the experiment. Center: aggression index and pursuit index when one fly is in top or side view and the other is in cross view. Due to limitation of cross view model detection, aggression index value range in this situation is approximately from –0.5 to 0.5, and pursuit index value range is approximately from 0 to 0.5. b. Fly pair distance (mm) across different genotypes. Left: fly pair distances in female-female assays across different genotypes. R26E01 > TRPA1 female pairs showed significantly shorter fly pair distance compared to the other five female groups. Right: fly pair distances in male–male. c. Aggression index across different genotypes. Left: aggression index in female–female assays. R26E01 > TRPA1 female pairs showed significantly higher aggression index compared to the other five female groups. Right: aggression index in male–male assays. d. Pursuit index across different genotypes. Left: pursuit index in female–female assays. Right: pursuit index in male–male assays. R72A10 > TRPA1 male pairs showed significantly higher pursuit index compared to the other five groups of male-male. For all six-group comparisons in b., c., and d., significant differences were identified in all comparisons (p < 0.05, Kruskal–Wallis test for fly pair distance and pursuit index for female pair and male pair and aggression index for female pair, and p < 0.05, one-way ANOVA test for aggression index for male pair). For post-hoc pairwise testing, Dunn’s test with Bonferroni-adjusted p-values was used after Kruskal–Wallis test: *** p < 0.0005; ** p < 0.005; * p < 0.05; ns: p ≥ 0.05, and Tukey’s test with adjusted p-values was used after one-way ANOVA test: *** p < 0.0005; ** p < 0.005; ns: p ≥ 0.05. Pink box: experimental group of female-female. Blue box: experimental group of male-male. Gray box: control groups of the sex in comparison. Red dot: individual female-female pair. Blue dot: individual male-male pair. Brown edge border: assay group for R26E01-GAL4 labeled neurons. Orange edge border: assay group for R72A10-GAL4 labeled neurons.