unc-69 affects axonal but not dendritic trafficking. (a,c) SNB-1::GFP is seen as evenly spaced puncta along the (a) VNC and (c) DNC in wild-type animals. (b,d,e) In unc-69(ju69) mutants, SNB-1::GFP puncta are on average bigger and often are absent from the VNC (arrowhead in (b)) and the DNC (arrowheads in (d,e)). In addition, SNB-1::GFP sometimes diffuses into the commissure (arrow in (d)). (a,b,e) Lateral views; (c,d) dorsal views of adult hermaphrodites. (f-i) As in (f,h) wild-type animals , neuronal morphology is grossly normal in (g,i) unc-69(ju69) mutants, and commissures still routinely reach the DNC. D-type GABAergic neuron morphology is visualized with the Punc-25::gfp transgene juIs76. (f,g) Lateral views; (h,i) dorsal views. (j) Distribution of SNB-1::GFP puncta in a stretch of axon labeled with Punc-25::DsRed monomer in the DNC in a unc-69(ju69) mutant hermaphrodite. SNB-1::GFP puncta are unevenly distributed, even though the DNC anatomy is grossly normal. (k) SNB-1::GFP is not significantly mislocalized into DD dendrites in unc-69(ju69) mutants. Animals carrying an snb-1::gfp transgene were scored at the L1 larval stage. Whereas 90% of unc-16(ju146) L1 larvae (n = 32) show dorsal GFP, 0% of wild-type L1s (n = 47) and 3% unc-69(ju69) L1s (n = 59) show dorsal GFP. Error bars represent the standard error of the mean. (l-n) The diacetyl odorant receptor ODR-10::GFP is targeted efficiently into AWB cilia both in (l) wild-type worms and in (m) unc-69(ju69) mutants. (n) In contrast, ODR-10::GFP becomes diffused in the dendritic targeting mutant unc-101. The arrow indicates the cilia; arrowheads indicate packets of ODR-10::GFP that shuttle in the dendrites. Anterior is to the left and dorsal is up.