Cm. Cox et Tj. Poole, Angioblast differentiation is influenced by the local environment: FGF-2 induces angioblasts and patterns vessel formation in the quail embryo, DEV DYNAM, 218(2), 2000, pp. 371-382
The embryonic vasculature forms by the segregation, migration, and assembly
of angioblasts from mesoderm, a process termed vasculogenesis. The initial
role of fibroblast growth factor 2 (FGF-2) in vascular development appears
to be in the induction of endothelial precursors, angioblasts. Quail somit
es transplanted into chick embryos will give rise to angioblasts of quail o
rigin, The number of angioblasts present within the chimera is dependent on
the host environment. Angioblast induction can be demonstrated in vitro by
the addition of FGF-2 to cultures of dissociated semitic mesoderm, as asse
ssed by QH-1 epitope expression. Manipulation of FGF-2 concentration in the
quail/chick chimeras by FGF-2 peptide or neutralizing antibody injections
increases or decreases angioblast induction in the predicted manner. To bet
ter control growth factor release in vivo we have implanted beads that rele
ase FGF-2 into the embryonic environment. FGF-2 beads implanted into the so
mite induce angioblast differentiation in the epithelial somite; whereas, b
eads lateral to the semitic mesoderm induce the formation of ectopic vessel
s. These studies suggest that FGF-2 is important for both the induction of
angioblasts and the assembly of angioblasts into the initial vasculature pa
ttern. Dev Dyn 2000;218:371-382. (C) 2000 Wiley-Liss, Inc.