Repulsive interactions instruct synaptic partner matching in an olfactory circuit.

Neurons exhibit extraordinary precision in selecting synaptic partners. Whereas cell-surface proteins (CSPs) mediating attractive interactions between developing axons and dendrites have been shown to instruct synaptic partner matching , it is less clear the degree to which repulsive interactions play a role. Here, using a genetic screen guided by single cell transcriptomes , we identified three CSP pairs-Toll2-Ptp10D, Fili-Kek1, and Hbs/Sns-Kirre-in mediating repulsive interactions between non-partner olfactory receptor neuron (ORN) axons and projection neuron (PN) dendrites in the developing olfactory circuit.