The nuclear receptor (NR) family of transcription factors is involved in various biological processes including the regulation of patterning during development, reproduction, metabolism, metamorphosis, and homeostasis. The
nhr-25 gene in C. elegans encodes a homologue of Drosophila Ftz-F1 and mammalian SF-1 nuclear receptors. Impairment of
nhr-25 activity leads to severe phenotypes in embryos and many post-embryonic tissues. Further analysis indicates that
nhr-25 activity is required for the proper development, including cell-cell fusion, of several epidermal cell types, such as the epidermal syncytial, seam and Pn.p cells. Our results also suggest that
nhr-25 is likely to regulate cell-cell junctions and/or fusion. In a subset of Pn.p cells, termed vulval precursor cells,
nhr-25 acts collaboratively with the
lin-39 Hox gene in regulating vulval cell differentiation. Additionally, our data suggests that
nhr-25 may also function with another Hox gene,
nob-1 , during embryogenesis. We are currently performing microarray analysis to identify potential transcriptional targets of
nhr-25 .