DNeuroFIG 8: The nerve ring as a proportion of body area in L2 and dauer larvae.
Cross-sectional views of the nerve ring in an L2 (A & C) and a dauer (B & D).
A & B. Transverse TEM sections of nerve ring and surrounding tissues.
C & D. Transparent color labeling of all tissues is superimposed on the TEM sections. Color code for labels: Neuron processes and cell bodies, orange; bodywall muscles, dark green; seam cells, brown; hypodermis, tan; excretory gland, magenta; amphid dendrites, pink; pharyngeal muscles, light green; pharyngeal marginal cells, purple.
(Image sources: N2 L2 28-14 [D. Riddle] 1089; Dauer N974 53089 F2 [D. Hall] 048.) The dauer sections are shown slightly enlarged in comparison to the L2 sections. Most tissues are relatively thinned in the dauer, while nervous tissue is not. Differences in fixation technique are not expected to cause any volume changes, since osmolarity has been kept equivalent. The dauer animal has become slightly distorted by the high pressure freeze, and there are some bacteria visible on its outer cuticle.
Click on picture for full resolution image.