Analysis of daf-11, a transmembrane guanylyl cyclase that mediates chemosensory transduction in C. elegans

Abstract

C. elegans daf-11 mutants have defects in chemosensory responses to a pheromone and to non-volatile and some volatile attractants. daf-11 encodes a transmembrane guanylyl cyclase (TM-GC) and provides the first example of a TM-GC that functions in taste and smell transduction. DAF-11 function also provides the first genetic model for this class of proteins. The cyclic GMP analogue 8-bromo-cGMP suppresses the pheromone response defect of daf-11 mutants, indicating that DAF-11 has a functional guanylyl cyclase activity. In C. elegans, specific neurons mediate specific sensory responses. daf-11::gfp expression is seen in five identified pairs of sensory neurons (ASJ, AWC, ASI, ASK, and AWB) in a pattern consistent with most daf-11 mutant phenotypes. daf-11 mutants also have defects in avoidance of the volatile repellent 2-nonanone. Mosaic analysis suggests that the pheromone response is more complex than previously thought. These results lead to a model for dauer pheromone response and will enable a greater understanding of smell and taste sensory transduction in C. elegans.