UNC-43 is required for the sexually dimorphic SVs abundance and cholinergic transmission. (A–C) Ultrastructural analysis of cholinergic SVs and DCVs in unc-43 mutant hermaphrodites (Herm.) and males (Male). (A) Representative micrographs of cholinergic synaptic profiles in unc-43 mutant hermaphrodites (Herm.) and males. The synaptic vesicles (SVs) are marked as green, the docked synaptic vesicles (DSVs) are marked as red, the dense core vesicles (DCVs) are marked as white, and the DP is marked as yellow. Scale bar, 200 nm. The number of total SVs (B) and DCVs (C) in 50-nm synaptic profile in hermaphrodites (Herm.) and males were measured in wild type (WT) and unc-43 mutants. The data used for the analysis of wild-type hermaphrodites and males is the same as presented in Fig. 4, A and B. (D–F) Endogenous acetylcholine transmission was assessed by recording mEPSCs from body-wall muscles of wild-type and unc-43 mutant adult hermaphrodites (Herm.) and males (Male). Representative mEPSC traces (D), the mean mEPSC frequencies (E), and the mean mEPSC amplitudes (F) are shown. The data for WT are the same as in Fig. 1, H and I. (G) Locomotion behavior analysis of unc-43 mutant hermaphrodites (Herm.) and males (Male). The averaged and individual crawling locomotion velocities were plotted. (H) Scatter plot showing the body-bend curvature in unc-43 mutant hermaphrodites (Herm.) and males (Male). (I) Body bends (Thrashes) in the liquid culture of unc-43 mutant hermaphrodites (Herm.) and males (Male). In B, C, and E–I, data are presented as mean values ± SEM. Ns represent the number of synapses analyzed for B and C and animals tested for E–I. One-way ANOVA with post-hoc Bonferroni’s multiple comparisons. *P < 0.05, **P < 0.01, ***P < 0.001, n.s. not significant.