Fig. 3. Immunohistochemical localization of Nek8. Confocal immunofluorescence microscopy using affinity-purified anti-Nek8 revealed strong expression in the apical cytoplasm of two-week-old wild-type inner medullary collecting duct cells (A) shown in cross-section. Similar sections from jck^-/- kidneys (B) show diffuse cytoplasmic Nek8 staining, often appearing as a perinuclear ring. Wild-type cortical collecting ducts also showed strong apical expression of Nek8 (C), while cystic collecting duct epithelia in jck^-/- tissue (D) show a diffuse pattern of cytoplasmic expression.