PN-ORN synaptic matching screens identify two Teneurinsa, d, Schematics showing two PN-ORN matching screens. PN dendrites are labeled by Mz19-GAL4 driving mCD8GFP and ORN axons by Or47b-rCD2 (a) or Or88a-rCD2 (d). Candidate cell-surface molecules are overexpressed only in Mz19 PNs. b-c, Or47b axons and Mz19 dendrites do not overlap in control (b), but form ectopic connections following Ten-m overexpression (c), as seen by axon-dendrite intermingling (arrowhead). e-f, Or88a axons and Mz19 dendrites connect at the VA1d glomerulus in control (e), but the connection is partially lost following Ten-a overexpression, as part of Or88a axons no longer intermingle with Mz19 dendrites (arrowhead). Target areas of Or47b (b-c) or Or88a (e-f) axons are outlined. Mismatching phenotypes are quantified in Fig. S9k and S10q. The first three columns in b,c,e,f show separate channels of the same section; the fourth shows higher magnification of the dashed squares (as in Fig. 3, 4, 5d-g.). Unless indicated, all images in this and subsequent figures are single confocal sections and all scale bars are 10 μm. g, Domain composition of Drosophila Ten-m and Ten-a. h, Phylogeny of the Drosophila Teneurins and related proteins in other species. Branch lengths represent units of substitutions per site of the sequence alignment. Teneurins are evolutionarily conserved in bilaterians and a unicellular choanoflagellate Monosiga brevicollis, but not in cnidarians.
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