Fig. 3. Peroxisome abundance and distribution along peripheral microtubules are perturbed in PEX1-null ZS cells. (A) PEX1-null patient HSFs processed with antibodies against PEX14 (green) and -tubulin (red). Top panels, minimal retraction of remnant peroxisomes; middle panels, pronounced remnant peroxisome retraction, with initial signs of clustering; bottom panels, dramatic clustering of remnant peroxisomes. Arrow indicates MTOC, corresponding to microtubule nucleation/anchor region. (B) Confocal laser-scanning microscopy showing remnant peroxisomes aligning (white arrowhead) or not aligning (white arrows) with microtubules. (C) PEX1-null cells stained for remnant peroxisomes using PEX14 antibody (green), and for lysosomes using LysoTracker Red DND-99 (red). (D) PEX1-null HSF cells stained for mitochondria using MitoTracker Green FM and MitoTracker Red CM-H₂XRos dyes. Bars, 20 µm (A,C,D); 5 µm (B).