title: In vivo analysis reveals a highly stereotypic morphogenetic pathway of vascular anastomosis.
abstract: Organ formation and growth requires cells to organize into properly patterned three-dimensional architectures. Network formation within the vertebrate vascular system is driven by fusion events between nascent sprouts or between sprouts and pre-existing blood vessels. Here, we describe the cellular activities that occur during blood vessel anastomosis in the cranial vasculature of the zebrafish embryo. We show that the early steps of the fusion process involve endothelial cell recognition, de novo polarization of endothelial cells, and apical membrane invagination and fusion. These processes generate a unicellular tube, which is then transformed into a multicellular tube via cell rearrangements and cell splitting. This stereotypic series of morphogenetic events is typical for anastomosis in perfused sprouts. Vascular endothelial-cadherin plays an important role early in the anastomosis process and is required for filopodial tip cell interactions and efficient formation of a single contact site.
authors.affiliation: Biozentrum der Universität Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Lenard
authors.forename: Elin
authors.initials: E
authors.lastname: Ellertsdottir
authors.forename: Lukas
authors.initials: L
authors.lastname: Herwig
authors.forename: Alice
authors.initials: A
authors.lastname: Krudewig
authors.forename: Loïc
authors.initials: L
authors.lastname: Sauteur
authors.forename: Heinz-Georg
authors.initials: HG
authors.lastname: Belting
authors.forename: Markus
authors.initials: M
authors.lastname: Affolter
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D015703:Antigens, CD / Q000378:metabolism; D019521:Body Patterning; D001921:Brain / Q000098:blood supply / Q000196:embryology; D015820:Cadherins / Q000378:metabolism; D002560:Cerebrovascular Circulation; D004730:Endothelium, Vascular / Q000196:embryology / Q000473:pathology*; D018507:Gene Expression Regulation, Developmental; D008856:Microscopy, Fluorescence / Q000379:methods; D009024:Morphogenesis; D009154:Mutation; D018919:Neovascularization, Physiologic; D011554:Pseudopodia / Q000502:physiology*; D015027:Zebrafish / Q000196:embryology; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D000099152:Cadherin 5