This invention pertains to the discovery that DPR-1 encodes a putative nuclear hormone receptor (NHR) that, based on gene reporter studies, is expressed in the endoderm throughout the life of the worm. NHR family members are transcriptional regulators that are activated when bound to their small lipophilic ligands such as steroids. While some NHRs are localized to the nucleus, others are cytoplasmic in the absence of ligand and translocate to the nucleus upon ligand binding. Once in the nucleus, they bind target sequences and regulate gene expression.