nhr-25, the Caenorhabditis elegans ortholog of ftz-f1, is required for epidermal and somatic gonad development

We have analyzed the expression and function of the Caenorhabditis elegans gene nhr-25, a member of the widely conserved FTZ-F1 family of nuclear rece ptors. The gene encodes two protein isoforms, only one of which has a DNA b inding domain. nhr-25 is transcribed during embryonic and larval developmen t. A nhr-25::GFP fusion gene is expressed in the epidermis, the developing somatic gonad, and a subset of other epithelial cells. RNA-mediated interfe rence indicates a requirement for nhr-25 function during development: disru ption of nhr-25 function leads to embryonic arrest due to failure of the ep idermally mediated process of embryo elongation. Animals that survive to ha tching arrest as misshapen larvae that occasionally exhibit defects in shed ding molted cuticle. In addition, somatic gonad development is defective in these larvae. These results further establish the importance of FTZ-F1 nuc lear receptors in molting and developmental control across evolutionarily d istant phyla. (C) 2000 Academic Press.