Figure 2. STAM-1A coexpresses with LOV-1 and PKD-2 in male-specific neurons and shows an endosome-like distribution pattern. (A) Anatomy of C. elegans male and PKD-2-expressing neurons. Modified from (Hu et al., 2006). Top, differential interference contrast (DIC) side view image of an adult C. elegans male oriented head (left) to ventral up tail (right). Middle,
lov-1 and
pkd-2 are expressed in male head CEM neurons (left) and tail ray B type neurons (except R6B) and the hook HOB neuron (right). Bottom, confocal micrographs of PKD-2::GFP expression pattern in male head and tail. The cilium, dendrite, cell body, and axon of the CEMD (dorsal CEM) and CEMV (ventral CEM) neuron are drawn in the male head diagram. CEM cilia are in the nose region (dashed rectangular box). The pharynx is green. Positions of nuclei of all
lov-1- and
pkd-2-expressing cells in the C. elegans adult male tail (modified from Sulston et al., 1980). Ray neurons are arranged as nine left-right bilateral pairs, numbered 1-9, anterior to posterior (ventral up view shown here). Rays are required for response to contact with a potential mate (Liu and Sternberg, 1995). HOB is an asymmetric ciliated hook neuron that mediates vulva location behavior (Liu and Sternberg, 1995). For simplicity, only the dendrite of R3B left and HOB is shown. The R3B cilium is indicated by a dashed rectangular box. (B) Confocal micrographs of Pstam-1::DsRed2 (using the
stam-1 promoter to drive DsRed2 expression) and PKD-2::GFP double-labeled C. elegans males. In all figures, adult males are oriented anterior to posterior, with the head pointing left and the tail pointing right.
stam-1 coexpresses with
pkd-2 in CEMs (head), RnBs, and HOB (tail, arrow points to HOB neuron). (C) With its native promoter, STAM-1A::GFP displays an endosomal-like pattern throughout the neuronal cell bodies. Note that STAM-1A also localizes to the cilia base of cilia in enlarged figure (right panel). In this and all subsequent figures, the arrow marks the ciliary base, and the arrowhead marks the approximate end of the cilium. (D) To clearly visualize the localization pattern of STAM-1A in polycystin-expressing neurons, the
pkd-2 promoter is used to drive
stam-1a cDNA expression only in CEMs, RnBs, and HOB neurons. STAM-1A localizes to the ciliary base (arrow), but is excluded from the cilium proper (region between arrow and arrowhead). Large green puncta are observed along distal dendrites of RnB ray neurons. Enlarged figures show the cilia region of CEM and R3B. Scale bars in rightmost C and D panels, 5 um; in all other micrographs scale bars, 10 um.