Figure 7
Primary cilia in kat 2 J/Nek1 −/− tubular epithelial cells. (A) In cultured HK2 human renal tubular epithelial cells, a portion of cellular Nek1 localizes at the base of primary cilia (or the centrosomes). Blue fluorescence from DAPI identifies nuclei, red identifies immunostained Nek1, and green identifies the primary cilium immunostained for acetylated tubulin. (B) Representative scanning electron micrograph of kidney from a kat2J/Nek1 −/− mouse with advanced PKD, showing a glomerular cyst and multiple tubular cysts. (C) Morphologically normal but long (5–9 μm) primary cilia are seen in tubular epithelial cells lining a cyst in the same kat2J/Nek1 −/− mouse kidney. (D) Wild type renal tubular epithelial cells cultured and passed multiple times have mostly normal and single primary cilia, stained at their base with a fluorescent green-tagged antibody recognizing acetylated tubules. Kat2J/Nek1 −/− cells from sex-matched littermates, cultured in identical conditions, had more variable primary cilia, including many cells with abnormally short, long, and multiple cilia. DAPI stains nuclei blue. Bar, 5 μm. (E) Cilia length in kat2J/Nek1 −/− kidney and cells. The length of cilia was measured using an image analysis program (AxioVision Rel 4.6, Carlo Zeiss). The mean lengths of the cilia are plotted with standard deviations. The number of cilia analyzed in images of cultured cells were n = 30 for wild-type cells, n = 25 for long cilia, and n = 16 for short cilia at2J/Nek1−/− cells. For the scanning EM images of kat2J/Nek1 −/− kidneys, n = 6 for long cilia, n = 10 for short cilia.