UNC-76 staining was visible throughout the nervous system of animals at all developmental stages from newly hatched larvae through adults. Embryos were not sufficiently permeabilized to allow anti-UNC-76 antibody staining, but
unc-76::lacZ fusions that appeared to be expressed normally in larvae and adults were expressed in a few cells, the identities of which were not determined, in embryos of about 200 cells, before the outgrowth of the first axons. UNC-76 staining in axons was strong throughout development, whereas cell body staining was strong in young larvae, but weaker in adults except for cell bodies in the head and tail ganglia. Of neurons with laterally positioned cell bodies, only the CAN and HSN cell bodies consistently contained UNC-76 protein in adults. The presence of C terminally truncated UNC-76 proteins in axons of mutant worms suggested that axon-targeting activity of UNC-76 resides in the N-terminal third of the protein.