Figure 5.
rab-5 M127N homozygotes are defective in endocytic uptake. (A) Steady-state levels of ssGFP (arIs37[myo-3p::ssGFP]) in rab-5 M127M#1 control edit homozygotes (top), rab-5 M127I#1 humanized edit homozygotes (middle) and rab-5 M127N#1 variant homozygotes (bottom). Representative GFP (above) and bright-field (below) images of the posterior half of worms are shown. In M127M#1 control edit and M127I#1 humanized edit homozygotes, there is rapid endocytic uptake of ssGFP from the body cavity (weak signal, orange arrow) into coelomocytes (white arrowheads). In M127N#1 variant homozygotes, ssGFP accumulates in the body cavity (strong signal, white arrows) with limited uptake in coelomocytes (white arrowhead), although this is difficult to visualize with the large amount of ssGFP in the surrounding body cavity. Scale bar, 50 μm. Full genotypes of strains are listed in Supplementary Material, Table S2. (B) Quantification of mean GFP fluorescence intensity per animal, in arbitrary units (AU) (assessed with ImageJ) for rab-5 M127M#1 control edit homozygotes (dark green), rab-5 M127I#1 humanized edit homozygotes (light green) and rab-5 M127N#1 variant homozygotes (dark red). Three independent biological replicates were combined for each genotype. n = 10 per condition. Scatter plots indicate the median with 95% confidence interval. Differences between groups were determined using ordinary one-way ANOVA followed by a Dunnett multiple-comparisons test. ns, not significant; ****P < 0.0001.