Fig. 3. C-terminal Inv regulates Inv protein localization to the Inv compartment in primary cilia. (A) A schema of the Inv protein. Numbers indicate the position of amino acids; white ovals represent ankyrin repeats; the blue and gray boxes represent the IQ1/IQ2 domains and the basic region (BR), respectively. (B) Localization of Inv (1-1062), Inv (1-743) and Inv (742-1062) in the primary cilium was observed by GFP fluorescence and DIC in living cells. Numbers indicate the position of amino acids. Inv-GFP constructs were introduced into the inv cell line. Arrowheads in the images indicate GFP signal and primary cilia. Primary cilia in living cells are seen as a dot. Results of the localization of GFP-tagged truncated Inv are summarized on the right (+, Inv present; +/–, part of the transfected cells shows ciliary localization of truncated Inv). Percentages of ciliated cells with ciliary GFP signal in transfected cells are also indicated. (C) Localization of Inv-GFP proteins in cilia was further confirmed by immunocytochemistry. Primary cilia were detected by anti-acetylated -tubulin antibody (ac-tubulin; red), and basal body or centrosome by anti--tubulin antibody (red). Inv (1-743) signal was localized throughout the entire length of the cilia with a punctate staining pattern. By contrast, the Inv (742-1062) signal was predominantly detected at the base of primary cilia excluding the basal body. Scale bars: 10 µm.