However, syncytium formation is inhibited
neither by taxol (Fig. 4A) nor by nocodazole (Fig. 4B). Interestingly,
nocodazole does not prevent the gathering of nuclei in syncytia (Supplemental
Figure S2B). Colchicine, another microtubule-destabilizing
agent, also does not inhibit syncytium formation (not shown).
Since disturbing the normal function and structure of the microtubular
network does not block syncytium formation for HAb2cells,we
conclude that microtubules and microtubule-dependent vesicle transport
do not play a major role in the expansion of fusion pores.