Figure 4. Lysosomal morphology and distribution during neurodegeneration. (A) Confocal images of wild-type touch receptor neurons expressing a
pmec-17 LMP-1::GFP transgene. LMP-1::GFP expression, differential interference contrast (DIC), and merged images are shown. Healthy neurons show a scattered and punctate pattern of lysosomal distribution. (i) Wild-type PVM touch receptor neuron. (ii) Wild-type ALM (left and right) touch receptor neurons. (B) Confocal images of PLM touch receptor neurons of
mec-4(d) animals expressing a pmec-17LMP-1::GFP transgene. During the early to middle (mid) stages of degeneration, lysosomes enlarge and appear to coalesce around a swollen nucleus (i-iv). Later on, the nucleus migrates to the periphery of the cell and condenses (iv-vi). At the late stage, no lysosome structure is evident and the vacuolated cell becomes diffusely fluorescent (vii and viii). (C) Acridine orange staining of a middle to late degenerating PLM touch receptor neuron. Acridine orange, DIC, and merged images are shown. Bars, 5 um.