1. Ghost bouton budding requires normal synaptic transmission and local retrograde BMP signaling.
Ghost bouton budding requires normal synaptic transmission and local retrograde BMP signaling. A, Wandering third instar animals were fixed in formaldehyde after high K+ stimulation and were stained with anti-HRP and anti-DLG to identify ghost boutons. Loss of Syt1 and postsynaptic knockdown of GluRIIA and GluRIIB reduce activity-dependent budding. Likewise, loss of the postsynaptic Ca2+ sensor Syt4, or postsynaptic knockdown of Gbb with the muscle driver 24B-Gal4, reduces ghost bouton budding. Knockdown of Gbb with the muscle 6-specific H94-Gal4 preferentially reduces budding at muscle 6. Scale bar, 12 μm. Arrowheads indicate ghost boutons. B, Quantification of ghost boutons per NMJ in the indicated genetic backgrounds. N (NMJs, animals): wild-type = 57, 11; syt1AD4/N13 = 45, 6; 24B, gluRIIARNAi = 31, 4; 24B, gluRIIBRNAi = 29, 4; 24B, gbbRNAi = 20, 3; syt4BA1 = 65, 11; 24B, syt4RNAi = ± 2.694, n = 31, 3; witA12/B11 = 37, 6. C, Quantification of baseline bouton number in the indicated genetic backgrounds. N, same as in B. D, The average number of ghost boutons that bud onto muscle 6 or muscle 7 is quantified for Gbb knockdown by the muscle 6-specific driver H94-Gal4. N (NMJs, animals): wild-type = 52, 7; H94, gbbRNAi = 40, 6. **p < 0.01; ***p < 0.001; ANOVA. Error bars indicate SEM.
Zachary D. Piccioli, and J. Troy Littleton J. Neurosci. 2014;34:
©2014 by Society for Neuroscience