Neuromuscular junction morphological defects in dnc, rut, and dnc rut larvae. (A) Anti-HRP antibody immunostaining in third instar larvae. Note that dnc and dnc rut displayed strikingly large type Ib boutons. Furthermore, the Ib and Is branches were dissociated in their projection in dnc. Typically Ib and Is branches run in parallel as shown in WT, rut, and dnc rut. (B) Boutons of larger sizes were more common in dnc larvae, as demonstrated by the diameter of largest bouton within individual NMJs. This phenotype was not rescued in the dnc rut double mutant. (C) Percentage of NMJs with multiple nerve entry points of Ib branch. Such abnormal ectopic entry was significantly increased in dncM11 and dncM14, but not in dnc1. This was not affected by rut and was partially rescued in the dnc rut double mutant. Groups of a, b, and c in (A) indicate significant differences between the group (p < 0.05; one-way ANOVA). Error bars indicate SD.