(A) Stacked and deconvoluted fluorescent images of DiI stained amphid neurons in a P. pacificus young adult hermaphrodite (left lateral view). AM9(ADF), AM4(ASK), AM2(ADL), AM1(ASH), and AM8(ASJ) amphid neurons stain robustly. (B) In C. elegans, DiI stains the ASK, ADL, ASI, AWB, ASH, and ASJ neurons. (C–H) Single plane fluorescent images in P. pacificus. (C–D) DiI stained Ppa-odr-3p::rfp transgenic J3 larvae showing the three dorsal amphid neurons and the larger ASH and ASJ neurons in two focal planes. (E) Ppa-che-1p::rfp transgenic J4 hermaphrodite showing expression in ASE and ASG. (F) A DiI stained Ppa-daf-6p::venus J4 larva showing ADL and ASJ staining, anterior to the amphid sheath and the excretory cells, respectively. (G, H) A DiO stained Ppa-odr-7p::rfp young adult in two focal planes showing dye filling in ADL and ASJ, and RFP expression in ADF and AWC. (G’ inset) The dendritic ends of another Ppa-odr-7p::rfp adult show the prominent PCMC of ADF with double cilia (bottom), and the smaller PCMC of ASK with a single cilium. (I) A DiO stained C. elegans young adult showing five dye filled neurons ASK, ADL, ASI, ASH, and ASJ. Scale bar: 5 µm. (C’–I’) DIC overlay of the same DiI fluorescence images. Anterior is left and dorsal is up. Scale bar: 20 µm. (Representative images based on: Ppa-odr-3p::rfp n = 22; Ppa-che-1p::rfp n = 31; Ppa-daf-6p::venus n = 60; PS312 n = 10; Ppa-odr-7p::venus n = 26). Additional Z-stacks are available: Figure 4—figure supplements 1–5 and Figure 1—videos 1–3.