Expression ofeat-4:: reporters. The reporter constructs schematically shown in Figure 1A were used to generate transgenic animals. A, Expression ofeat-4:: lacZ(nls) in the pharynx, observed with Nomarski optics. β-Galactosidase activity was found in the nuclei of two types (each consists of a bilaterally symmetric pair) of pharyngeal neurons, M3 andNSM. Also seen in this panel is the strong signal in the nucleus of an extrapharyngeal cell posterior to M3. This extrapharyngeal cell is probably a neuron in the IL1 class.B, C, Expression ofeat-4:: gfp in extrapharyngeal neurons. The identity of these cells is marked either in the figure (B) or above the photograph (C). The identity of one cell (marked asAVJ or AIN) is uncertain. InB, the entire animal is shown, whereas inC only the head is shown. Only the right half of the animal is shown in C, because these classes of cells are bilaterally symmetric. C, Shown is an overlay (with Adobe Photoshop software) of nine serial confocal images with an intersection spacing of 0.9 μm.