unc-108 (Rab2) mutants have strongly reduced levels of PC2-processed Venus cargo in their axons. (A–E) Representative images of Venus-tagged neuropeptides in DA/DB motor neuron axons in animals with the indicated genetic backgrounds. Strains containing the same transgenic array are scaled identically for brightness after adjusting for differences in light source power. NLP-21–Venus and INS-22–Venus are expressed from the integrated transgenic arrays nuIs183 and nuIs195, respectively. (A–C) UNC-108 is required for normal levels and density of the Venus cargo in axons. (D and E) A peptide tag not cleaved from the proneuropeptide by PC2 convertase is transported to axons in unc-108 mutants. (F) Quantification of Venus cargo fluorescence in the dorsal axons of unc-108 mutants. The graph shows the total integrated fluorescence per micrometer of dorsal axon length, expressed as a percentage of the wild-type control, of various tagged neuropeptides in the indicated mutant backgrounds. Data are means and SEMs from images acquired from 6 to 16 individual animals each. NLP-21–Venus, FLP-3–Venus, ANF-Venus, and INS-22–Venus were expressed from the integrated transgenic arrays nuIs183 (or ceIs56 for nu415), ceIs61, ceIs62, and nuIs195, respectively. P-values are from a Mann-Whitney test and unpaired t test with Welch correction.