FIG 5.

Run-reverse-flick motility in solutions of 1.2% mucin in M9MM. (a) Three example trajectories in 1.2% mucin, with marked reverse, flick, and deceleration events. (b) Distribution of instantaneous swimming speeds observed in the presence (red) and absence (blue) of mucin. The average speeds are 57 μm/s in mucin and 94 μm/s in M9MM. (c) Distribution of relative swimming speeds in the presence (red) and absence (blue) of mucin. The relative speed is the instantaneous swimming speed divided by the individual’s median swimming speed. (d) Bivariate histogram of consecutive turning angles in 1.2% mucin also displays alternating flicks and reversals as well as consecutive reversals, consistent with run-reverse-flick motility. (e) Distribution of turning angles and classification of turn events for trajectories in M9MM (gray; reproduced from Fig. 1d) and in mucin (black). The average flick angle is 88° ± 26° (mean ± SD) in M9MM and 97° ± 33° in 1.2% mucin/M9MM. The average reversal angle is 169° ± 6° in M9MM and 168 ± 7° in mucin. (f) Fraction of turn events classified as flicks (orange), reversals (teal), or unidentified (white) in the absence and presence of 1.2% mucin. Turns of an angle up to 140° are considered flicks, those above 150° are reversals, and those in between 140° and 150° are considered unidentified. Absolute numbers of events for each category are given.