Fig. S3.

F-actin and Myo8 are not required for gametosome formation. (A and B) Time-lapse imaging of mCherry–α-tubulin (magenta) and Citrine-MAP65d (green) during the first division of the gametophore initial cell with (B) or without (C) 200 µM Cytochalasin B, an actin inhibitor. Images were recorded every 2 min. Time 0 corresponds to the timing of NEBD. Arrowheads indicate loosened MT interdigitations, which lack prominent Citrine-MAP65d signals. Gametosomes are marked by arrows. (Scale bar, 10 µm.) (C) Immunostaining of endogenous MTs in the gametophore initial of the myo8 null mutant confirmed the Myo8-independent formation of the gametosome. Images were acquired with six z-sections (separated by 1 µm), and displayed after maximum projection. (Scale bar, 10 μm.)