eff-1 Expression in Fusing Cells. Expression of
eff-1p::gfp in wild-type embryos and worms.(A-C) Time course of expression in a single embryo.(A) An approximately 500-cell embryo (250 min) showing first expression of GFP in epidermal precursors.(B) Ventral view of enclosed embryo (340 min) with GFP in ventral (v) and dorsal (d) epidermal cells.(C) Lateral view at 1.5-fold stage (430 min), with GFP throughout
hyp6 and
hyp7 syncytia and in tail spike cells (ts).(D) L2 showing GFP in lateral and dorsal
hyp7, but no expression in the seam cells (se). A seam daughter cell (se-
hyp7) expresses GFP intensely before fusing to
hyp7.(E) Head of adult hermaphrodite, with GFP in pharyngeal metacorpus (ph), dorsal
hyp7, amphid sheath cells (as), and neuronal axons (ax) projecting from the nerve ring (nr).(F) Midsection of mid-L3 with GFP in lateral (top) and ventral (bottom)
hyp7. Dividing unfused VPCs remain unlabeled.(G) Vulval morphogenesis in mid-L4. Subset of vulval cells express GFP (green overlaid on DIC). Three-dimensional reconstruction of two tetranucleated toroids (inset, rotated 90) shows lumen (open arrowhead) forming through centers of toroids (arrow and filled arrowhead).(H) Midsection of gravid hermaphrodite showing GFP in a uterus containing embryos.(I) Copulatory bursa of adult male tail with GFP in fan and rays. Asterisks show cells not known to participate in cell fusion. The scale bars represent 10 um.