Figure 1. The egl-19(gof) Timothy syndrome mutation causes defects in axon termination and neuronal polarity.

(A) Example of normal axon termination in a wild-type ALM neuron, where the axon terminates posterior to the tip of the nose (arrow). (B) Example of axon termination defect in egl-19(gof) mutants, where the ALM axon extends to the tip of the nose (arrow). (C) Quantification of axon overextension defects in ALM neurons. (D) Example of a normal cell body of a wild-type ALM neuron, where a single process extends from the anterior side of the ALM cell body. (E) Example of a multipolar phenotype in egl-19(gof) mutants, where a short process extends from the posterior side of the ALM cell body. (F) Quantification of the multipolar phenotype that is caused by the egl-19(gof) mutants. Axons are visualized with the muIs32 transgene that encodes Pmec-7::gfp. Arrows point to the tip of the ALM axon. Asterisk marks the anterior-most part of the worm. + indicates ALM cell body. P indicates a multipolar defect. Scales bars are 10um. Between 100 and 150 axons were observed in L4 stage hermaphrodites per genotype. Asterisks indicate statistically significant difference, Z-test for proportions (**p<0.0005; ***p<0.0001). Error bars represent the standard error of the proportion.