Figure 8. Formation of the apical protrusion is correlated with the Roll movement and hair cell (HC) positioning.

(A) Maximum intensity projection and 3-D rendering of selected images of nascent sibling HCs in myo6b:Yfp-tubulin larvae (magenta and green dots) that was treated with nocodazole for 90 min immediately after the precursor divided. The apical protrusion that normally forms within 18 min was still evident initially (18 min; red and white arrowheads) but disappeared quickly between 30 and 36 min (asterisks, 48 min). After nocodazole removal, the apical protrusion reappeared after 12 min (102 min, red and white arrowheads) and the two nascent HCs rolled to their respective positions after 84 min (186 min). (B) A nascent HC pair (red and green dots) that was treated with nocodazole for 150 min immediately after the precursor divided. Similar to 90 min treatments, the apical protrusion was evident between 12 and 18 min (12 min, red and white arrowheads) after HC precursor divided (0 min) but disappeared shortly within 30–36 min (54 min, asterisk). However, after nocodazole removal at 150 min, sibling HCs did not form an apical protrusion and exchange positions (162–240 min, asterisks).

Figure 8—video 1. Time-lapse video of nocodazole treatment for 90 min of a myo6b:Yfp-Tubulin hair cell (HC) pair shown in Figure 8A.

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Nocodazole was added at 0 min immediately after the HC precursor (−6 min, yellow dot) divided and they were incubated with nocodazole for 90 min (0–90 min). After nocodazole was removed, the HC pair underwent the Roll phase to exchange positions with each other (96–186 min).

Figure 8—video 2. Time-lapse video of nocodazole treatment for 150 min of a myo6b:Yfp-Tubulin hair cell (HC) pair shown in Figure 8B.

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Nocodazole was added at 0 min immediately after the HC precursor (−6 min, yellow dot) divided and they were incubated with Nocodazole for 90 min (0–150 min). After nocodazole removal, the HC pair did not undergo the Roll phase to exchange positions with each other (162–240 min).