Figure 3. UNC-31 is expressed in neurons and is enriched at synapses. A, Confocal image of an adult hermaphrodite expressing GFP under the
unc-31 promoter (oxEx608[Punc-31:GFP]). Expression of
unc-31 is pan-neuronal with additional expression in the spermatheca and vulval muscles. Anterior is left. B, Confocal image of the ventral surface of an adult hermaphrodite expressing GFP under the
unc-31 promoter. Expression is observed in the vulval muscles VM1 and VM2. Expression is also seen in the UV1 cells. C, Confocal images of
unc-31(
e928) oxEx608[UNC-31:GFP]. UNC-31:GFP protein localizes to the synaptic-rich region of the nerve ring as well as the dorsal and ventral nerve cords. GFP expression inside the dashed circle around the posterior bulb of the pharynx can be disregarded because it arises from the coinjection marker (Pmyo-2:HIS::GFP). Additional diffuse expression of the coinjection marker can also be seen in the isthmus of the pharynx. D, Subcellular localization of UNC-31:GFP in the SAB neurons of the head. Punctate expression as well as colocalization with the synaptic vesicle marker synaptobrevin (a-SNB-1) indicate that UNC-31 is localized to synaptic terminals, reported previously by Charlie et al. (2006).