Losses of FAP256, CHE12 and ARMC9 affect cilia. (A) Swimming velocities of growing wild type (WT; 0.41 mm/s; n = 31), FAP256-KO (F-KO; 0.27 mm/s; n = 22), CHE12-KO (C-KO; 0.29 mm/s; n = 16), and ARMC9-KO (A-KO; 0.2 mm/s; n = 15) cells. The asterisks mark significant differences as compared with the wild type (two-sided t test, P < 0.001). (B) The rates of phagocytosis expressed as the number of ink-filled food vacuoles per cell after 10 min of exposure to india ink (asterisks show significant differences as compared with wild type; n = 50 cells; two-sided t test, P < 0.05). (C) Rates of pair formation. Wild-type or KO cells were mixed with an equal number of wild-type cells of a complementary mating type, and the percentage of cells in pairs was scored 6 h later (asterisks show significant differences compared with the wild-type cross; n = 100 cells; two-sided t test, P < 0.05). (D) Ciliary beat frequencies of wild type (39.8 ± 4.2 Hz, n = 109), FAP256-KO (34 ± 4.4 Hz, n = 58), CHE12-KO (37 ± 5.8 Hz, n = 95 cilia), and ARMC9-KO cells (20.5 ± 6.2 Hz, n = 37 cilia). Error bars represent standard deviations, asterisks indicate statistical significance compared with the wild type (two-sided t test, P < 0.05). (E and F) Space-time diagrams that document ciliary motility based on the Videos 3 and 6. Using a Matlab application, the area around the cell containing cilia was extracted as a video, unfolded, and used to create a space-time diagram. The x axis represents the position of cilia along the Tetrahymena cell surface (A, anterior; P, posterior end of the cell). The y axis represents time in milliseconds. Each short diagonal line represents a single cilium moving along the cell surface over time. The red arrows mark an example of a single beat cycle, and the red rectangle marks an example of a paralyzed cilium.