Ultrastructural analysis of synapses at NMJs. (A–C) The GFP-RAB-3 driven by unc-129 promoter has no sex-differential expression. The puncta fluorescence intensities and densities of GFP::RAB-3 driven by unc-129 promoter in dorsal nerve cord axons in the adult hermaphrodites (Herm.) and males (Male). Representative images (A), mean puncta intensity (B), and density (C) are shown. Scale bars, 10 μm. Data are presented as mean values ± SEM. (D) Representative micrographs from the serial sections with each containing a 50 nm cholinergic synaptic profile. (E) Representative of 50 nm cholinergic synaptic profile. Yellow arrows indicate the dense projection (DP). Scale bar, 200 nm. The representative images shown in the figure are derived from the same dataset as presented in Fig. 4, A and B. (F) Representative transverse section through the ventral and dorsal cord (left) and process identifications (right) in hermaphrodites (Herm.) and males. The sequence of motor neuron classes from dorsal to ventral is VD, DD, VA, and VB. NMJs are made between motor neurons and muscle arms (M). Scale bar, 500 nm. Two-tailed and unpaired Student’s t test for B and C. n.s., not significant.