Fig. 3.

M. sexta Orco KOs show disrupted or reduced olfactory responses to plant headspace and to ecologically relevant single odors. (A) D. wrightii headspace collection was used to stimulate male and female antennae (for gas chromatogram see SI Appendix, Fig. S4). (Top) Presumed neural activity patterns from Ca²⁺ response in male and female antennal lobes (ALs) after stimulation with D. wrightii headspace in solvent. Pattern of responses varies based on sexual dimorphic morphology of the M. sexta AL (Top; ref. 119). False color-coded images are representative Ca²⁺ activity responses from right ALs; entrance of the antennal nerve is in the upper left. Images were generated by subtracting the frame before stimulus onset from the frame with the maximum response. Calcium activity was normalized for each image and color-coded (see color bar). (B) Heat-map representation of median EAG response values (millivolts) corrected for the response to the solvent from male and female antennae (***P ≤ 0.001, **P ≤ 0.01, *P ≤ 0.05; n.s., not significantly different from 0; Wilcoxon rank sum test versus zero). Box-plot representation and corrected median values with individual P values are shown in SI Appendix, Figs. S5 and S6 and Tables S2 and S3. Sample size of all 3 genotypes for headspace and single odorants male and female in parentheses (n). (C) Neural activity in the AL of males and females in response to stimulation with benzaldehyde (floral odor) and hexanoic acid (vegetative odor) as these elicit the strongest EAG responses in the Orco KO hawkmoth.