Using a fosmid-based reporter transgene, the previously reported expression of
unc-6 in the AVG neuron up to early larval stages was corroborated. However, the expression in the AVG neurons of hermaphrodites begins to fade during the L3 stage, before sexual maturation, and is undetectable by the young adult stage. In contrast, expression is maintained in males during sexual maturation in the L4 stage into the young adult stage. Non-dimorphic
unc-6 expression is observed in other neuron classes, some of which maintain
unc-6 expression into adulthood (e.g., RIF neurons), whereas others do not (e.g., AVA neurons). Consistent with the expression pattern of the fosmid reporter, we observed robust
unc-6 mRNA signals (single molecule FISH) in both sexes of first larval stage animals and strongly sexually dimorphic levels during sexual maturation in the L4 stage.