A Nwk-binding mutant of Snx16 recapitulates the nwk phenotype. (A) Representative confocal projections of anti-complexin (Cpx) staining from NMJs of the indicated genotype under the control of the elav^C155 GAL4 driver. (B) Quantification of the mean bouton number for muscle 6/7. (C) Quantification of the mean bouton number for muscle 4. (D) Quantification of the mean satellite bouton number for muscle 4. (E) Cooverexpression of Nwk-mRFP suppresses the Snx16 but not the Snx16^3A overexpression phenotype. Black bars indicate control animals expressing mRFP, and red bars indicate animals expressing Nwk-mRFP. (F) Snx16^3A overexpression increases BMP signaling. Trio protein levels are increased in muscle 6/7 NMJs. Error bars are means ± SEM, and the number of samples averaged in each measurement is indicated at the base of each bar. *, P < 0.05; ***, P < 0.005. Bars: (A) 20 µm; (F) 5 µm.