Fig. 2

PECAM-1-unrelated trans-cellular migration at sites remote from junctions. Monocyte M1 underwent trans-cellular migration at a site relatively remote (>20 μm) from the nearest junction (arrows at 38–47 min), but the related PECAM-1 was not observed. A movie clip for the entire time series, in which its dynamic process can easily be recognized, is available as supplemental movie 1. M1 seemed to be in contact with another monocyte M2 located beneath endothelium that had previously transmigrated (arrowheads at 43–47 min), and the two monocytes seemed tightly stuck to each other at 47 min (arrow and arrowhead). Red monocytes. Green PECAM-1-GFP in ECs. The location of endothelial cell borders was delineated as curved white lines at 47 min. Time after monocyte addition in minutes is shown in the upper-left corner. Maximum-projected xy-images toward the z-axis are shown, with xz/yz orthogonal images cut with the specified planes that are indicated as white lines on xy-images. At 45 min, z-stacks were optically separated into “apical” and “basal” sections. Bar 20 μm