Figure 3.

Axon guidance receptors compartmentalize in the axon of Drosophila melanogaster neurons. (A) In D. melanogaster, the axons of commissural neurons cross the midline of the ventral nerve cord through the anterior commissure (AC), avoiding the repellent Wingless/Integrated Wnt5 (purple) present on the posterior commissure (PC), and then extend anteriorly. These neurons display striking axonal compartmentalization of the axon guidance receptor molecules Derailed (pink), localized to the proximal region, and Roundabout (ROBO) molecules (orange), localized to the distal region; (B) Intrinsic mechanisms are required for this compartmentalization, as the same pattern of localization is also observed in the neurons in culture in the absence of external guidance cues.