A. Localization of hypodermal and seam nuclei in a 430-minutes (after first cleavage), tadpole-stage embryo, view from dorsal. Anterior hypodermal cells later migrate, acquiring shapes similar to the arcade cells. Numbers correspond to the hyp cells (1 is hyp 1, etc.).Darker nuclei are the closest to the dorsal side. (e) Excretory pore; (a) anus (based on Sulston et al., 1983).
B. The localization of anterior hyp and seam-cell nuclei in an L2 stage animal, left lateral view. Each nucleus is schematically drawn over the DIC image. Solid-colored nuclei lie in the lateral planes and transparent ones in the midplane. Left lateral (posterior) and midplane (anterior) aspects of the DIC image are separated by a thin black line. The right side is a mirror image of the left, except there is no hyp 2 on the right. At this stage, the anterior hypodermal cell somata (hyp 1-6) are situated posterior to the anterior rings because of embryonic cell migrations (see HypFIG 5 and HypFIG 10). The positions of nuclei are determined from TEM sections of the N2T animal (MRC archive), and there may be slight variations between individual animals.
C. DIC image of the same animal as in B, from a strain expressing the Y37A1B.5::GFP reporter in the hypodermis (top panel), with an epifluorescent image overlain on the DIC image (bottom panel). Hypodermal nuclei that are visible at this plane are marked by arrowheads (top panel); black arrow marks a body wall muscle nucleus (BWmu). Remaining nuclei belong to arcade cells, neurons and glia. Nuclei of hyp 6 and hyp 7 cells expressing GFP are located in dorsal and ventral ridges around and posterior to the anterior bulb of the pharynx (arrowheads, right panel). The white arrow points to the junction between hyp 5 (no GFP expression) and hyp 6 (with GFP expression). Original magnification, 600x. (Strain source: The Genome BC C. elegans gene expression consortium; McKay et al., 2004.)

See also HypFIG 11D-F.

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