Immunolocalization of Neks in Giardia trophozoites. (a) Giardia trophozoites expressing hemagglutinin (HA)-tagged putative active Neks 5375, 16279, 92498, and 101534 were probed with an anti-hemagglutinin-FITC antibody. Each Nek had a distinct cytoskeletal (5375, 16279, 92498, and 101534) or cytoplasmic (101534) localization pattern. In addition to the PFRs, two Neks localized to the ventral attachment disk and the median bodies (16279 and 92498). A trophozoite cartoon further illustrates each specific Nek localization. Nuclei are labeled with DAPI and a differential interference contrast (DIC) image of each trophozoite is shown on the far right. Scale bar = 5 μm. (b) Giardia trophozoites expressing full-length Nek 15409 and Nek 15409 with the deleted ankyrin repeat were probed with an anti-AU1 antibody and visualized with confocal microscopy. Z-stack images, shown on top and to the right of each image, show that deletion of the ankyrin repeats altered the distribution of 15409 from solely cytoplasmic to a combination of plasma membrane-associated and cytoplasmic. Scale bar = 5 μm.