Fig. 4. Activation phenotypes of brain dsx neurons across three species.

a Confocal images of female dsx brain neurons in the brain (top) and VNC (bottom) of each species. Only two pairs of neurons, vpoDN and DNp13^37,44, project into VNC. Arrowheads highlight VNC projections of vpoDN and arrows highlight that of DNp13. The neuron schematic of vpoDN is based on our confocal images and the neuron schematic of DNp13 was adapted from⁴⁴ with permission from the publisher. Scale bars: 50 µm. n = 10 biological replicates for each species over 2 rounds. b–i, Behavioral phenotypes of optogenetically activating dsx brain neurons in intact (b–e) and decapitated (f–i) females of each species. b, d, f, h Mean normalized abdomen length (b, f) and wing angle change (d, h) of intact females (b, d) at 1.6 μW/mm² or decapitated females (f, h) at 0.8 μW/mm². Activation window is denoted by bars above each plot. Shaded areas represent the SEM. Inset diagrams illustrate how abdomen lengths or wing angles were measured. n = 10 (D. melanogaster), 8 (D, yakuba), 9 (D. santomea). c, e, g, i Maximum normalized abdomen length (c, g) and wing angle change (e, i) of intact females (c, e) or decapitated females (g, i) under each activation intensity. Two-sided Mann-Whitney U tests were performed only between D. melanogaster and D. santomea (activation triggered female song in D. yakuba). Curve and error bars show mean ± SEM. n = 10 (D. melanogaster), 7 (D, yakuba), 8 (D. santomea). Source data are provided as a Source Data file.