Combinatorial function of ETS transcription factors in the developing vasculature

Laboratory of Molecular Genetics, National Institute of Child Health and Human Development/NIH, Building 6B, Room 309, 6 Center Drive, Bethesda, MD 20892, USA.
Developmental Biology (Impact Factor: 3.55). 04/2007; 303(2):772-83. DOI: 10.1016/j.ydbio.2006.10.030
Source: PubMed


Members of the ETS family of transcription factors are among the first genes expressed in the developing vasculature, but loss-of-function experiments for individual ETS factors in mice have not uncovered important early functional roles for these genes. However, multiple ETS factors are expressed in spatially and temporally overlapping patterns in the developing vasculature, suggesting possible functional overlap. We have taken a comprehensive approach to exploring the function of these factors during vascular development by employing the genetic and experimental tools available in the zebrafish to analyze four ETS family members expressed together in the zebrafish vasculature; fli1, fli1b, ets1, and etsrp. We isolated and characterized an ENU-induced mutant with defects in trunk angiogenesis and positionally cloned the defective gene from this mutant, etsrp. Using the etsrp morpholinos targeting each of the four genes, we show that the four ETS factors function combinatorially during vascular and hematopoietic development. Reduction of etsrp or any of the other genes alone results in either partial or no defects in endothelial differentiation, while combined reduction in the function of all four genes causes dramatic loss of endothelial cells. Our results demonstrate that combinatorial ETS factor function is essential for early endothelial specification and differentiation.

Download full-text


Available from: Daniel Castranova,
  • Source
    • "Several zebrafish transcription factors that regulate hematopoiesis have been identified. The early stage markers gata2, lmo2, fli1, and scl (stem cell leukemia) are master regulators that are coexpressed in both the ALM and PLM, where hemangioblast development occurs, from the 2nd to the 3rd somite stages [20] [21] [23]. These genes are expressed in the PLM and later in the intermediate cell mass (ICM) [28– 31]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Myeloid malignancies are heterogeneous disorders characterized by uncontrolled proliferation or/and blockage of differentiation of myeloid progenitor cells. Although a substantial number of gene alterations have been identified, the mechanism by which these abnormalities interact has yet to be elucidated. Over the past decades, zebrafish have become an important model organism, especially in biomedical research. Several zebrafish models have been developed to recapitulate the characteristics of specific myeloid malignancies that provide novel insight into the pathogenesis of these diseases and allow the evaluation of novel small molecule drugs. This report will focus on illustrative examples of applications of zebrafish models, including transgenesis, zebrafish xenograft models, and cell transplantation approaches, to the study of human myeloid malignancies.
    BioMed Research International 06/2015; 2015. DOI:10.1155/2015/641475 · 2.71 Impact Factor
  • Source
    • "Likewise, pdgfrb transcript was reduced in pdgfrb um148 mutant embryos and western blot analysis confirmed the absence of protein (Figures 2J and 2K). Embryos bearing mutations in amot, elmo1, and ets1 also displayed normal vascular patterning and circulatory function despite previous reports of defects in respective morphant embryos (Table S3; data not shown; Aase et al., 2007; Epting et al., 2010; Pham et al., 2007). In the case of the ets1 um206 mutation , we detected transcripts missing exon 3, which contains the um206 deletion, in heterozygous and mutant embryos (Figures 2L and 2M), while all remaining sequenced full-length transcripts bore the um206 deletion (data not shown). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The widespread availability of programmable site-specific nucleases now enables targeted gene disruption in the zebrafish. In this study, we applied site-specific nucleases to generate zebrafish lines bearing individual mutations in more than 20 genes. We found that mutations in only a small proportion of genes caused defects in embryogenesis. Moreover, mutants for ten different genes failed to recapitulate published Morpholino-induced phenotypes (morphants). The absence of phenotypes in mutant embryos was not likely due to maternal effects or failure to eliminate gene function. Consistently, a comparison of published morphant defects with the Sanger Zebrafish Mutation Project revealed that approximately 80% of morphant phenotypes were not observed in mutant embryos, similar to our mutant collection. Based on these results, we suggest that mutant phenotypes become the standard metric to define gene function in zebrafish, after which Morpholinos that recapitulate respective phenotypes could be reliably applied for ancillary analyses. Copyright © 2015 Elsevier Inc. All rights reserved.
    Developmental Cell 12/2014; 32(1). DOI:10.1016/j.devcel.2014.11.018 · 9.71 Impact Factor
  • Source
    • "To investigate the transcriptional regulation of etv2, we performed bioinformatic analyses to identify genomic elements that direct the vascular specific expression of etv2 during embryonic development . Etv2 and fli1, a second transcription factor with vascular function (Brown et al., 2000; Pham et al., 2007) are juxtaposed in opposite orientations on chromosome 16 with a space of approx. 4.1 kb distance between respective first exons separating the two genes (Fig. S1A). "
    [Show abstract] [Hide abstract]
    ABSTRACT: E-twenty six variant 2 (Etv2) transcription factor participates in cardiac, vascular-endothelial and blood cell lineage specification decisions during embryonic development. Previous studies have identified genomic elements in the etv2 locus responsible for vascular endothelial cell specification. Using transgenic analysis in zebrafish, we report here an etv2 proximal promoter fragment that prevents transgene misexpression in myocardial progenitor cells. This inhibition of etv2 expression in the cardiac progenitor population is partly mediated by Scl and Nkx2.5, likely through direct binding to the etv2 promoter, and cis-regulatory elements located in the first and second introns. The results identify an etv2 cis-regulatory mechanism controlling cardiovascular fate choice implying that etv2 participates in a transcriptional network mediating developmental plasticity of endothelial progenitor cells during embryonic development.
    Developmental Biology 06/2014; 393(1). DOI:10.1016/j.ydbio.2014.06.019 · 3.55 Impact Factor
Show more