Fig. 5. Endocytosis in fission yeast is associated with actin. (A,B) FM4-64 uptake is inhibited in the actin mutant cps8 even at the permissive temperature of 25°C (B). Note the bright fluorescence at the cell membrane, particularly at the equator of dividing cells. (A,C) FM4-64 uptake is not inhibited in the -tubulin mutant nda2 at the restrictive temperature (36°C). (D) FM4-64 internalisation is inhibited in the Arp2/3 complex mutant arp2 at the restrictive temperature but not in the formin mutant for3 (E). (F,G) Syb1 vesicles at the poles and the equator show different sensitivity to latrunculin. Whereas vesicles in dividing cells collapse to the cell membrane in low latrunculin concentrations, higher concentrations are required to disrupt Syb1 vesicles at the poles of interphase cells. (G) Syb1-GFP collapses to the membrane in latrunculin-treated cells (Lat A). Bars, 10 µm.