Live imaging of dynamic cell-cell contact between Csf1r-EGFP+ macrophages and Flk1-myr::mCherry+ vessels.

<p>Live imaging was performed at the angiogenic front of <i>Csf1r-EGFP</i>^<i>+/tg</i><i>; Flk1-myr</i>::<i>mCherry</i>^<i>+/tg</i> corneas implanted with PDGFBB/FGF2-releasing hydrogel at day 4 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131643#pone.0131643.s007" target="_blank">S5 Movie</a>) and day 11(<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131643#pone.0131643.s008" target="_blank">S6 Movie</a>) post-implantation. A series of images extracted from time lapse movie indicates that macrophages bridge endothelial tip cells potentially facilitating vessel anastomosis and vessel sprouting at day 4 (a) (see text for details). At 11 days post-implantation, the macrophage population is less dynamic and exhibits an elongated, pericyte-like morphology lining the vessels suggestive of a possible long-term supportive role in maintaining vessel stability (b).