Fig. 8. Venous endothelial cells and wound healing.

Zebrafish regenerate amputated caudal fins. During the regeneration process, reactivation of endothelial migration is essential to support angiogenic activity. After amputation (1), chemotaxis from the wounded area attracts ECs (2). Among the three different EC subtypes, only venous ECs respond to angiogenic factors from the wounded area and initiate migration into the wound (3). During the migration of venous ECs, they differentiate into tip ECs (3). Then, venous EC-derived tip ECs change the direction of migration, migrate toward the artery and differentiate into arterial ECs (4).