Localized netrins act as positional cues to control layer-specific targeting of photoreceptor axons in Drosophila.

摘要: A shared feature of many neural circuits is their organization into synaptic layers. However, the mechanisms that direct neurites to distinct layers remain poorly understood. We identified a central role for Netrins and receptor Frazzled in mediating layer-specific axon targeting Drosophila visual system. expressed cell autonomously required R8 photoreceptors directing axons medulla-neuropil layer M3. Netrin-B specifically localized this owing axonal release by lamina neurons L3 capture by target neuron-associated Frazzled. Ligand expression sufficient rescue axon-targeting defects Netrin mutants. normally despite replacement diffusible membrane-tethered ligands. Finally, localization instructive because ectopic can retarget axons. propose provision chemoattractants intermediate represents highly precise strategy positionally defined layer.