Figure 4

unc-129::gfp expression in the ten-1(ok641) and unc-129(ev554) mutants. All panels show worms transgenic for a unc-129::gfp reporter expressed in the DA/DB neurons and in the dorsal muscle cells. (A) Shows a control worm in which one clear circumferential axon is in indicated by the filled arrowhead. (B) Shows a ten-1(ok641);unc-129(ev554) double mutant where the same axon errs and branches abnormally (open arrowhead), and the dorsal muscle expression is dramatically enhanced compared to control (arrow). (C-D) Show lower magnification views of animals with the indicated genotypes. Filled arrowheads indicate axons that projected correctly circumferentially, while open arrowheads indicate axons that erred and branched abnormally, failing to reach the dorsal side. The scale bar in (A) applies also to (B), while the scale bar in (C) applies to panels (C-F).