Fluorescent images illustrating the angles tracked for MTR-labeled mitochondrial movement in GFP expressing WT and dotA−L. pneumophila- infected cells (A).
“V” represents the vacuole containing the bacterium, “i” indicates the initial position of the mitochondrion, and “f” indicates the final position of the mitochondrion. The relative frequency of the angle of mitochondrial movement towards or away from the vacuole at 1 hour post infection of WT and dotA− L. pneumophila-infected S2 cells are shown in (B, C). The data are represented as the relative frequencies (in 15° bins) as indicated by the length of the lines displayed over 180°. The origin of all radiating relative frequency lines corresponds to the initial position “i,” as shown in (A), for each mitochondrion. All angle measurements considered included only the smaller θ between the three points; thus allowing all angles to be plotted on a semi-circle. Non-moving mitochondria were excluded from the analysis. The distribution of directions of movement was significantly different between the WT and dotA− infected cells at 1 hr post-infection (p<0.01; Kolmogorov-Smirnov two-sample test). Scale bar, 20 µm.