Septin is recruited transiently to CEV before actin tail formation. (A) Immunofluorescence analysis reveals CEV, detected with the B5 antibody before membrane permeabilization, either recruit septin (yellow arrows) or induce actin tails (pink arrows) but not both. The graph shows the quantification the percentage of CEV colocalizing with SEPT7 or inducing actin tails. Error bars represent SEM from three independent experiments in which 900 CEVs were analyzed in 30 cells. (B) Video stills from live cell imaging of HeLa cells expressing LifeAct-iRFP (Actin) and GFP-SEPT6 and infected with WR encoding A3-RFP (virus). SEPT6 is recruited to CEV but is lost when actin polymerization starts. The white dotted line corresponds to the initial microtubule-dependent movement of virion to the cell periphery. The time in seconds is indicated. See Video 2. Bars, 2 µm.