::gfp reporter was found to be expressed in the nuclei of many epidermal cells, including the epidermal syncytial cells, the seam cells, and all the Pn.p cells and their progeny. Many cells in the head and tail also showed nhr-25
::gfp expression. nhr-25
expression was first observed during embryogenesis around the 100-cell stage and continued to be expressed throughout development in the epidermal and seam cells. In the Pn.p-derived vulval cells, when vulval morphogenesis (including cell division, fusion, and migration) was almost complete during the L4-to-adult transition, nhr-25
::gfp expression significantly decreased, whereas in other Pn.p cells that fused with hyp7
::gfp expression remained largely unchanged.