Fig. 4. Marker expression in Y and PDA. (A) The epithelial marker CHE-14::GFP is expressed in Y. (Right) Fluorescent photomicrograph of Y expressing CHE-14::GFP in a newly hatched L1 animal (40 of 40 early L1s expressed che-14
in Y). (Left) The corresponding Nomarski photomicrograph. CHE-14 can be detected at the apical side of the Y cell, bordering the rectal slit (white arrow), and some faint fluorescence can be seen in Y cytoplasm; note that both sides of the rectal slit are marked with CHE-14, although only one is shown in focus; arrowhead, Y nucleus. (B) The epithelial markers DLG-1 and AJM-1 are expressed in Y. Fluorescent photomicrographs of the subapical part of the Y cell (white arrowheads) expressing both DLG-1 (green, Left) and AJM-1 (red, Center) in the same L1 animal (overlay in yellow, Right; 41 of 41 and 27 of 27 early L1s expressed dlg-1
in Y respectively); thin arrow, rectal slit. (C) PDA is a neuron in the L3 stage. Photomicrograph of the PDA motor neuron cell body (arrowhead) and axonal process (thick arrow) in a cog-1
::gfp L3 larva. PDA's axon is first directed toward the posterior of the animal on its ventral side, then it runs round to the dorsal side through a right-handed commissure past the rectum (thick arrow) and goes toward the anterior part of the worm in the dorsal cord. In cog-1
::gfp or ace-3
/4::gfp animals, PDA's process (thick arrow) stops just posterior to the pharynx (asterisk). The anus is indicated by a thin arrow.