In acutely infected ISE6 cells, membrane proliferation and vesicles were also observed ( Fig. 7B & C) , but the extent was notably less widespread than in mammalian cells, consistent with the findings of previously published work [35] . The vesicles were also found in dilated ER cisternae and were the same diameter as those seen in Vero cells (Fig. 7C) . Virions were not detected until 96 hpi (data not shown), likely a consequence of the lower viral titer and slower replication observed in the tick cells (Fig. 1B) . The membranous tubules or vesicles were present at a slightly higher frequency than in acutely infected Vero cells.