Fig. 3

Sexual dimorphisms in the auditory efferent innervation of all three mosquito species JO horizontal sections were stained with the presynaptic marker 3C11 (anti-synapsin, green) to label auditory efferent fibres²³ and counterstained with the neuronal marker anti-HRP (red) for Ae. aegypti (AEG), Cx. quinquefasciatus (QUI) and An. gambiae (GAM). a, e, f Sketches of the three different patterns of efferent innervation observed. Efferent fibres are classified according to the region innervated: underneath the basal plate (green); base of auditory cilia (dark blue); somata (light blue); auditory nerve (yellow). The coding colour also applies to the arrowheads in b–i. AX axons, C auditory cilia. Modified from refs ^7,8,23. a–d Male mosquito JO of all three species present an extensive efferent innervation pattern—as revealed by 3C11 staining—in the basal plate (green arrowheads), base of auditory cilia (dark blue arrowheads), intermingled among somata (light blue arrowheads) and in the auditory nerve (yellow dash line). e, g, h In AEG and QUI females, the efferent fibres innervate the base of the auditory cilia (dark blue arrowheads) and somata region (light blue arrowheads). f, i Efferent innervation in GAM females is limited to dispersed punctae intermingled among the somata (light blue arrowhead). 3C11 also stains motoneuronal innervation of muscles in the scape (arrow). Scale bar: 10 µm. Supplementary Figure 5 contains single channel, as well as merged, images