wts-1 mutants show the premature structural and functional decline of touch receptor neurons (TRNs)
(A, B) Representative images of TRNs ([A] ALM and [B] PLM) in the wild-type and wts-1(ok753) mutant at the L4 stage. In the mutant, morphologically disrupted ALM and PLM were observed to exhibit abnormalities including ectopic swelling/branching on the processes and posterior outgrowth (arrowheads). (C) Newly developed ALM and PLM in the wild-type and the wts-1(ok753) mutant at the early L1 stage. The intact neuronal process is indicated using arrowheads. Intestinal expression of the WTS-1 rescue construct (Popt-2::WTS-1::GFP) is indicated using an arrow. (A–C) TRNs were visualized by expressing GFP under the control of the mec-7 promoter (muIs35[Pmec-7::GFP]) and anterior is to the left unless otherwise noted. Scale bar = 20 μm. (D) Penetration of defective TRNs of the wild-type and the wts-1(ok753) at different developmental stages. Neurons displaying any morphological abnormalities such as swelling, branching, somatic outgrowth and extended distal process were scored as defective neurons. In one experiment, 30 cells were observed for each strain and each stage and the experiments were repeated 3 times. Statistical significance was determined by a two-way ANOVA followed by Bonferroni’s post-test. (E) Quantified touch responses of the wild-type and the wts-1(ok753) mutant at L4 and 1st day of adulthood (1DA). N = 30. Statistical significance was determined by an unpaired t-test. ***, p < 0.001, **, p < 0 .01, *, p < 0.05, n.s, not significant, compared to WT or control, unless otherwise marked on graph. All data are presented as means ± SEM, unless otherwise noted.