Fig. 2. zag-1 mutations block formation of stereotypic axon branches and cause pathfinding defects. Wild-type (A,C,E,G) and zag-1 (B,D,F,H) GFP-transgenic animals. Neurons: ADE (A,B); PDE (C,D); PVC (E,F) (additional GFP-labeled axons present in VNC); ALM and AVM (G,H). (H) AVM often terminates at the nerve ring in zag-1 mutants, although in this image AVM is wild type. Arrows indicate locations of missing axon branches and asterisks indicate ectopic glr-1::gfp-expressing neurons. (I) Schematic of wild-type and zag-1 axonal structures, not to scale. Anterior is leftwards (A,B,E,F,I), anterior is rightwards (C,D,G,H), dorsal is towards the top.