Effect of Jasp treatment on NRG-induced free barbed end formation. (A) Images of Alexa 546–actin. MCF-7 cells were treated with 0.05 µM Jasp or DMSO for 10 min and then with NRG for 3 min. Free barbed end formation was visualized by Alexa 546–actin incorporation into the cell periphery (arrows). Bar, 20 µm. (B) Quantification of free barbed ends. The mean fluorescence intensity of Alexa 546–actin in a region 1 µm from the cell edge (red region) of Jasp-treated cells was compared with that of control cells (left). Right panel shows the relative FDAP of 0.05 µM Jasp-treated or untreated cells, obtained from Fig. 8 A. Data are means ± SEM of 26–38 cells (Alexa 546–actin) and 16–17 cells (FDAP). *, P < 0.05.