When the fluorescent reporter Venus was fused to the 3.5 kb
lury-1 promoter (
lury-1prom), the expression of Venus was observed only in two classes of pharyngeal neurons. These neurons were identified as the M1 and M2 neurons by their morphology, position, and the co-expression of established cell markers (Kim and Li, 2004; Refai et al., 2013). We found that the
lury-1prom::Venus reporter was robustly expressed in M1 in all larval stages and in adults, whereas its expression in M2 was not detectable in most L1-L3 worms but started to increase from the L4 stage.