The C. elegans che-1 gene encodes a zinc finger transcription factor required for specification of the ASE chemosensory neurons.

Chemotaxis to water-soluble chemicals such as NaCl is an important behavior of C. elegans when seeking food. ASE chemosensory neurons have a major role in this behavior. We show that che-1, defined by chemotaxis defects, encodes a zinc-finger protein similar to the GLASS transcription factor required for photoreceptor cell differentiation in Drosophila, and that che-1 is essential for specification and function of ASE neurons. Expression of a che-1::gfp fusion construct was predominant in ASE. In che-1 mutants, expression of genes characterizing ASE such as seven-transmembrane receptors, guanylate cyclases and a cyclic-nucleotide gated channel is lost. Ectopic expression of che-1 cDNA induced expression of ASE-specific marker genes, a dye-filling defect in neurons other than ASE and dauer formation.