Fig. 3. UNC-119 functions cell-autonomously to suppress axon branching. (A) Expression of a GFP-tagged UNC-119 protein in the GABA motor neurons of an unc-119(ed3) mutant restored GABA motor axon structure (arrowheads). Note that there were no gaps in the dorsal nerve cord (arrow). (B) GFP expression in the CAN lateral cord neurons (arrowhead) of wild-type animals. The lateral cord axons were not branched. (C) The CAN axons of unc-119(ed3) mutants were branched (arrowhead). (D) Expression of a GFP-tagged UNC-119 protein in the GABA neurons of unc-119(ed3) mutants (left arrow) failed to rescue the branching of the CAN axons (arrowhead). (E) 100% of D-type motor neuron axons in wild-type worms were morphologically normal (black, n=16 worms, 96 axons). Only 27% ±2.8 of VD and DD axons were normal in unc-119(ed3) mutants (gray, n=9 worms, 144 axons). Expression of a GFP-tagged UNC-119 protein in the GABA neurons of unc-119(ed3) mutants restored the morphology of the DD and VD axons (white, 85% ±7.3, n=10 worms, 95 axons). (F) 100% of wild-type worms scored had unbranched lateral nerve cord CAN axons (black, n=12 worms). All of unc-119(ed3) mutants scored had branched CAN axons (gray, n=10 worms). Expression of a GFP-tagged UNC-119 protein in the GABA neurons of unc-119(ed3) mutants failed to rescue the branched morphology of the CAN axons (white, 8% n=13 worms). Scale bars (A-D) 10 µm.
