Fig. 4. Mesodermal and neuronal defects in zag-1(hd16). (A,B) Wild-type and zag-1(hd16) larvae after 1 hour incubation with fluorescent latex beads. Fluorescent material was transported into the gut in wild type (A), but remained in the anterior part of the pharynx in zag-1 (B). zag-1(hd16) also has pronounced axon guidance defects. (C) zag-1(hd16) L1 larva expressing glr-1::GFP; the arrow indicates an axon extending laterally, arrowheads indicate ectopically expressing cells, and dotted lines indicate ventral cord defasciculation. (D) zag-1(hd16) L1 larva expressing unc-47::GFP; the arrows indicate commissures not reaching the dorsal cord but extending processes in a lateral position, arrowheads indicate gaps in the ventral cord, dotted lines indicate ventral cord defasciculation. Ventral aspect in C,D; side views in A,B. Anterior is to the left. Scale bars: 20 µm.