GFP was expressed in several head neurons located on the sides of the pharynx anterior bulb, around the isthmus and on the sides of the pharynx posterior bulb. Some neuronal processes were fluorescent in the ventral cord down to the tail ganglion, where several neurons expressed GFP as well as several nuclei of hypodermal cells at the tip of the tail. Histochemical staining of mutant ace-1
revealed a strong positive reaction in the nerve ring (NR), the pharyngo-intestinal valve (PIV), the tail ganglion and in the ventral nerve cord, with possibly stained motoneurons which were not labelled with GFP. Head neuron staining allowed identification of the inner labial neurons (IL). AWC and possibly AWB were identified. Cell bodies of these four chemosensory neurons were located below the nerve ring. Other head neurons cannot be identified because of the lack of clear labelling of their processes. The three muscle cells of the pharynx isthmus (pm5
) were also fluorescent. In the tail region, three neurons were tentatively identified as PVC and PVQ and PDA. At the tail tip, five fluorescent nuclei of hypodermal cells (hyp 8, hyp 9, binucleated hyp 10 and hyp 11) were identified.