Fig. 3. Class 3 and 4 TbCMF mutants have clear motility defects. The indicated mutants were assessed for cell motility defects using a sedimentation assay (A) (Bastin et al., 1999; Ralston et al., 2006) and by direct observation using DIC microscopy (B). In both cases, cells were assayed before significant clustering was evident to avoid secondary effects on motility. (A) Sedimentation curves. OD is the difference between the average OD₆₀₀ readings for sedimented (S) and resuspended (R) samples. Error bars show a standard deviation of three independent experiments. A trypanin knockdown mutant (Hutchings et al., 2002) is included as a control for samples without (-tet) and with (+tet) motility defects. (B) Time-lapse series taken from a video clip of TbCMF 46 (a Class 3 mutant) grown in the absence (-tet) or presence (+tet) of tetracycline for 30 hours. The black arrow marks the point of origin at the start of the time-lapse series while the white arrow follows the cell. Bar, 10 µm. A video of TbCMF 46 motility is provided as supplementary material Movie 2. Additional movies of WT (Movie 5), class 2 (TbCMF 3, Movie 1) and class 4 (TbCMF 5, Movie 4; TbCMF 9, Movie 3) are provided as supplementary material.