Distinct requirements for zebrafish angiogenesis revealed by a VEGF-A morphant.
Angiogenesis is a fundamental vertebrate developmental process that requires signalling by the secreted protein vascular endothelial growth factor-A (VEGF-A). VEGF-A functions in the development of embryonic structures, during tissue remodelling and for the growth of tumour-induced vasculature. The study of the role of VEGF-A during normal development has been significantly complicated by the dominant, haplo-insufficient nature of VEGF-A-targeted mutations in mice. We have used morpholino-based targeted gene knock-down technology to generate a zebrafish VEGF-A morphant loss of function model. Zebrafish VEGF-A morphant embryos develop with an enlarged pericardium and with major blood vessel deficiencies. Morphological assessment at 2 days of development indicates a nearly complete absence of both axial and intersegmental vasculature, with no or reduced numbers of circulating red blood cells. Molecular analysis using the endothelial markers fli-1 and flk-1 at 1 day of development demonstrates a fundamental distinction between VEGF-A requirements for axial and intersegmental vascular structure specification. VEGF-A is not required for the initial establishment of axial vasculature patterning, whereas all development of intersegmental vasculature is dependent on VEGF-A signalling. The zebrafish thus serves as a quality model for the study of conserved vertebrate angiogenesis processes during embryonic development.
Nasevicius
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A
Arnold and Mabel Beckman Center for Transposon Research, Department of Genetics, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
Larson
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J
Ekker
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SC
D000818:Animals; D001808:Blood Vessels / Q000196:embryology*; D019521:Body Patterning; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D047108:Embryonic Development; D016228:Endothelial Growth Factors / Q000235:genetics* / Q000502:physiology*; D015870:Gene Expression; D018390:Gene Targeting; D009025:Morpholines; D009154:Mutation; D018919:Neovascularization, Physiologic; D016376:Oligonucleotides, Antisense; D010641:Phenotype; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000235:genetics / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*
D004268:DNA-Binding Proteins; D016228:Endothelial Growth Factors; D009025:Morpholines; D016376:Oligonucleotides, Antisense; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D017978:Receptors, Growth Factor; D015534:Trans-Activators; D042461:Vascular Endothelial Growth Factor A; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor