Extended Data Fig. 1: Inter-fly distances below 8 mm approximate courtship in the dark.
From: A modular circuit coordinates the diversification of courtship strategies
a, Automated scoring of the samples plotted in Fig. 1b. (Left) percent time pairs spent at IFD < 8 mm and (Right) average bout length at IFD < 8 mm after first interaction (eug) or after courtship initiation (all other species). Each data point represents the individual pairs shown in the heatmaps in Fig. 1b (n = 12 each) b, (Top) Inter-fly distance (IFD) traces over time for a single representative pair of D. simulans or D. yakuba as courtship proceeds. Comparison of manually confirmed courtship bouts with those estimated by IFD thresholding revealed that an IFD threshold of 8 mm most accurately replicated manual scoring, resulting in the lowest incidence of false positives and negatives. (Bottom) Courtship bouts approximated by IFD < 8 mm thresholding compared to manual scoring by a blinded observer. Red dotted lines indicate initiation of courtship. c,d, Comparison between the percent time courting and the average courtship bout length scored by automated IFD < 8 mm thresholding versus manually scored by a blinded observer for the same courting pairs across species (c) or for D. yakuba male courtship of oenocyte-less females perfumed with the D. yakuba pheromone 7-T (d)(n = 12 each). Generally, IFD-thresholding overestimates the total amounts of courtship (due to incidental periods where flies are close but not courting) and underestimates the average courtship bout length (due to transient periods where the female moves away from the male but courtship continues), but captures the overall trends observed in samples manually scored by a blinded observer (Fig. 1c, d). The samples analyzed here in c are the same plotted in Fig. 1b and the samples analyzed in d are the same plotted in Fig. 1d (n = 10 each). All quantifications are of the 10 min period following courtship initiation. Data points represent individual males, bars are median. Statistics: Kruskal-Wallis tests (a). Letters denote statistically different groups (p < 0.05).
