Figure 2. GCY-35 and GCY-36 Activity in the URX Body Cavity Neurons Is Sufficient to Promote C. elegans Social Feeding. (A-C) Both
gcy-35 (A) and
gcy-36 (B and C) reporters are expressed in the neurons AQR, PQR, and URX. These neurons are directly exposed to the body fluid of C. elegans.
gcy-35 expression is also seen in SDQL/R, ALN, PLN, AVM, and occasionally in another unidentified cell.(D and E) Targeted expression of
gcy-35 in AQR, PQR, and URX by using the
gcy-32 promoter or in URX by using the
flp-8 promoter is sufficient to restore social feeding behavior to
gcy-35;
npr-1 animals (D). Similarly, targeted expression of
gcy-36 from the
gcy-32 or
flp-8 promoter restores social feeding to
gcy-36;
npr-1 animals. Expressing N terminally GFP-tagged GCY-36 from the
gcy-36 promoter also restores aggregation and bordering, but this rescue is disrupted if the CAAX box is mutated (E). In this and subsequent figures, the genotype to which transgenes were added is indicated under the bracket. In (D) and (E), with the exception of the gfp:
gcy-36(C672S) transgene, p < 0.001 for comparisons between gcy;
npr-1 transgenic animals and nontransgenic controls for both aggregation and bordering behaviors.(F-I) GFP-tagged GCY-36 is enriched in sensory cilia of AQR (F) and PQR (G). URX neurons are not ciliated. This enrichment is dependent on an intact C-terminal isoprenylation site: mutating this site disrupts GCY-36 rescuing activity (E) and prevents GCY-36 accumulation in cilia (H and I).