Fig. 6. Bchs localization in presynaptic endings. (A) Bchs immunoreactivity (red) within the third-instar larval brain and nerve cord is enriched in the synaptic neuropil, marked with Synaptotagmin1 immunoreactivity (green). Bchs immunoreactivity is undetectable in bchs¹². (B) When expressed in the adult ellipsoid body, HA-tagged Bchs (red) accumulates in the axon terminals of EB neurons, while transmembrane mCD8::GFP (green) distributes evenly throughout these neurons. Stars denote EB neuron presynaptic terminals, arrowheads point to EB neuron dendrites, arrows point to EB cell bodies. (C) In a confocal stack of images from a third-instar NMJ (muscle 6/7), Bchs immunoreactivity (red) is enriched in synaptic boutons. The neuronal membrane is outlined by anti-HRP (green). (D) In a single confocal section, Bchs puncta (red) are visible within the HRP-labeled (green) neuronal ending. The specificity of this immunoreactivity is confirmed by its absence in bchs⁵⁸. Scale bars: 20 µm in C; 5 µm in D. EB, ellipsoid body.