Selective release of WPB membrane proteins during a lingering kiss. In each case the image montages in panels A to D show the fluorescence of a Proregion-EGFP (Pro-EGFP; top panels) containing WPBs during complete exocytosis (panels A and C) or during a lingering kiss (panels B and D) evoked by histamine (100 μM). The fluorescence of P-selectin-mRFP (panels A and B) or mRFP-CD63 (panels C and D) coexpressed with Proregion-EGFP are shown in the lower panels. Scale bars are 2 μm. The time-course for dispersal of Proregion-EGFP (black traces) and P-selectin-mRFP or mRFP-CD63 (gray traces) from the WPBs shown are plotted below each montage. Data in panels A and B were acquired at 0.83 frames per second, and in panels C and D at 30 frames per second.