Fig. 4. kette and sra-1 affect synaptic development. Neuromuscular junctions (NMJ) of muscle 4 taken from third instar larvae are shown. Boutons are labeled by Nc46 expression. The inlay shows a higher magnification of a terminal bouton highlighted by the boxed area. (A) Wild-type NMJ. Note the smooth morphology of the terminal boutons. Almost no extra branches or buds can be detected. (B) After sra-1 RNA interference, an increased budding of terminal boutons was noted (elavGal4xUASsra-1^RNAi). (C) Third instar larvae carrying the weak hypomorphic allele combination kette^J1-70/kette²⁶. There is an increase in budding tendency, which is particularly evident at the terminal boutons. (D) A similar phenotype was observed following neuronal expression of the sra-1C^Myr deletion construct (elavGal4xUASsra-1C^Myr).