Receptor expression:
- GCY-25; transmembrane receptor guanylate cyclase
- GCY-32; soluble guanylate cyclase
- GCY-34; soluble guanylate cyclase
- GCY-35; soluble guanylate cyclase, binds molecular oxygen and mediates oxygen sensation. Heterodimerizes with GCY-36
- GCY-36; soluble guanylate cyclase
- GCY-37; soluble guanylate cyclase
- NPR-1; receptor for flp-18- and flp-21-encoded peptides
Function:
- Functions in aerotaxis, and along with PQR, URX and AUA regulate social feeding (or aggregation on a bacterial lawn) and bordering (the accumulation of animals on the thickest part of a bacterial lawn) behaviors. Suppressing the activity of AQR, PQR and URX neurons inhibits social feeding (Coates and de Bono , 2002). AQR, PQR and URX function as sensors of environmental oxygen which is a quantitative regulator of social feeding (Gray et al., 2004). Studies indicate that animals that carry the npr-1 (215F) low-activity allele or that lack npr-1 function tend to dwell (slow down) on food in low ambient O₂ and roam around or aggregate (at the borders of the food lawn) in high ambient O₂. In this model, drops in O₂ lead to increased activity of a GCY-35/GCY-36 heterodimeric soluble guanylate cyclase. Rising cGMP, in turn, opens the TAX-2/TAX-4 cGMP-gated ion channel in AQR, PQR and URX leading to their depolarization and when food is present, strong suppression of roaming behavior (Cheung et al., 2005). In npr-1 mutants these neurons are thought to be hyperactive (see URX page for a full description).
- AQR, PQR and URX suppress innate immunity via NPR-1, which regulates both PMK-1-dependent and PMK-1-independent immune responses (Styer et al., 2008). Since URX, AQR, PQR are exposed to pseudocoelomic fluid, they are hypothesized to communicate neuroendocrine signals to nonneural tissues involved in innate immunity defense responses.
- AQR, PQR and URX are weak CO₂-sensors and contribute to CO₂ avoidance (main CO₂ sensors are AFD, BAG and ASE) (Bretscher et al., 2011).
Reporters:
- At CGC: ZG611 iaIs19 [gcy-32p::GFP + unc-119(+)]. Expression of gcy-32::GFP is consistenly observed in AQR, PQR, and URX neurons.
- Other: