The aryl hydrocarbon receptor (AHR) functions in higher organisms in development, metabolism and toxic responses. Its Caenorhabditis elegans (C. elegans) ortholog, AHR-1, facilitates neuronal development, growth and movement. We investigated the effect of AHR mutation on the transcriptional profile of L4 stage C. elegans using RNA-seq and quantitative real time PCR in order to understand better AHR-1 function at the genomic level. Illumina HiSeq 2000 sequencing yielded 51.1, 61.2 and 54.0 million reads from wild-type controls,
ahr-1(
ia03) and
ahr-1(
ju145) mutants, respectively, providing detection of over 18,000 transcripts in each sample. Fourteen transcripts were over-expressed and 125 under-expressed in both
ahr-1 mutants when compared to wild-type. Under-expressed genes included soluble guanylate cyclase (gcy) family genes, some of which were previously demonstrated to be regulated by AHR-1. A neuropeptide-like protein gene,
nlp-20, and a F-box domain protein gene
fbxa-192 and its pseudogenes
fbxa-191 and
fbxa-193 were also under-expressed. Conserved xenobiotic response elements were identified in the 5' flanking regions of some but not all of the gcy,
nlp-20, and fbxa genes. These results extend previous studies demonstrating control of gcy family gene expression by AHR-1, and furthermore suggest a role of AHR-1 in regulation of a neuropeptide gene as well as pseudogenes.