Drosophila melanogaster rearing and staging details

Flies were reared at room temperature (22–25°C) and humidity on standard cornmeal medium. The following lines were acquired from Bloomington Drosophila Stock Centre: CenG1A^EY01217 (15502), Lat⁶ (5571), Leo^12BL (9572), Psn¹⁴³ (8297), Df(2L)BSC6 (6338), Df(2L)BSC105 (8671), Df(2L)BSC694 (26546), Df(2L)Exel7080 (7853), Df(3L)BSC669 (26521), Df(3L)BSC671 (26523), Df(3L)Exel6092 (7571), elav-GAL4 (8765), nSyb-GAL4, OK6-GAL4 (64199), OK371-GAL4 (26160), UAS-Dscam2-RNAi (51839), UAS-mCD8::GFP (5137), UAS-PLCδPH-mCherry (51658), and UAS-2xFYVE-myc-GFP (42712). The following fly lines were generated in the Millard laboratory and have been previously described: Dscam2^null-1 and Dscam2^null-3 (Millard et al., 2007), Dscam2A-GAL4, and Dscam2B-GAL4 (Lah et al., 2014). All animals selected for experiments were on a w¹¹¹⁸ background, and larvae of either sex were selected only if in wandering third-instar stage. Experiments used larvae and embryos raised at 25°C unless otherwise specified. Embryos of either sex were staged to within a 2-h window.