ceh-14 expression starts around the 280 min stage mainly in the anterior part of the embryo. In later stages (comma stage), the expression is seen in more cells in the head, but also in some cells in the tail. Judged by position and shape, most of them are neuronal precursors, although we have not precisely identified them. From larval to adult stages, neuronal expression is observed in the ALA interneuron and a pair of sensory neurons, AFDL/R, in the head, and in the BDUL/R interneurons in the anterior body (see also Cassata et al., 2000a). In the tail, we see expression in the sensory- and interneurons PHAL/R, PHBL/R, PHCL/R, DVC, PVCL/R, PVNL/R, PVQL/R, PVT, PVWL/R and PVR. The neuronal expression in the head and tail is confirmed by an anti-CEH-14 rabbit antiserum. We also note expression in the six touch neurons ALML/R, AVM, PVM and PLML/R, although it is seen only in strains with integrated reporter constructs. In addition to the neuronal expression,
ceh-14 expression is also seen in the hypodermis and spermatheca as previously described (Kagoshima et al., 2000).