Fig. 1: TBC-10 and UNC-70/β-spectrin function in the epidermis to protect against axonal breakage.

a Scheme showing the location and morphology of the PLM touch receptor neuron. b A schematic transverse section through the animal (dotted line in a) illustrating the region in which the PLM axon is ensheathed in the epidermis and attached via hemidesmosomes. c An image and scheme showing a typical unbroken axon of the PLM neuron in unc-70(n493) mutants visualized with GFP (transgene zdIs5(Pmec-4::GFP)). d An image and scheme showing a typical broken axon of the PLM neuron in tbc-10(vd31);unc-70(n493) animals. e Mean penetrance of axonal breakage in wild-type, unc-70(n493) mutants, and multiple alleles of tbc-10 in an unc-70 background. f Mean penetrance of axonal breakage in tbc-10;unc-70 mutants carrying transgenes expressing wild-type tbc-10 under either an endogenous promoter, a touch receptor neuron-promoter, an epidermal-specific promoter, or a muscle-specific promoter, versus their respective non-transgenic siblings. g Mean penetrance of axonal breakage in tbc-10(vd31);unc-70(n493) mutants carrying transgenes expressing the wild-type human orthologs tbc1d10a-c under an epidermal-specific promoter versus non-transgenic siblings. h Mean penetrance of axonal breaks in tbc-10 single and tbc-10(vd31);unc-70(n493) double mutants, versus tbc-10(vd31) mutants expressing single-copy insertions of the semi-dominant UNC-70(DN)::mKate2 driven by touch receptor neuron or epidermal-specific promoters. Scale bar in c = 50 μm. P-values in e and h are determined from a one-way ANOVA with a Tukey multiple-comparison of proportions using an Agresti–Coull interval. P-values in f and g are determined from a comparison of proportions using an Agresti–Coull interval. Error bars indicate a 95% confidence interval. N-values are indicated on bar graphs and represent the number of individual animals scored for each condition. Source data are provided as a Source Data file.