Figure 4. Tel1 Regulates VegfA Expression in the DLP and Somites, and VEGFA Rescues the Programming of Hemangioblasts, the DA, and HSCs in Tel1 Morphants (A) In situ hybridization analysis showing that Tel1 and VegfA expression overlap in several tissues, including the DLP and somites. BA, branchial arches; s, somites. (B) Analysis of VegfA expression in Tel1-depleted embryos. A general reduction of VegfA expression is observed in Tel1 morphants, with the greatest reductions in the DLP (arrows) and the somites. (C) qPCR analysis of the levels of VegfA mRNA in wild-type and Tel1 morphant DLP (top) and somite (bottom) explants (see Experimental Procedures). Explants were taken at stage 27, and RNA was extracted and assayed for VegfA expression normalized to ODC. Error bars indicate the SEM. (D) Expression analysis showing that VegfA mRNA (2 ng) injection into Tel1 morphants rescues hematopoietic (Scl) and endothelial (Flt1 and Flt4) gene expression in the DLP (arrows). Exogenous VegfA also rescues expression of Dll4 in the DA (arrows) of morphants and, in addition, induces ectopic expression of Dll4 in other blood vessels (arrowheads). A total of 54% of morphants recover Runx1 expression in the ventral wall of the DA (arrows). (E) Expression analysis on stage 43 sectioned embryos shows that exogenous VegfA mRNA rescues expression of Scl (red arrows) in the ventral wall of the DA of Tel1 morphants. n, notochord; PCV, posterior cardinal vein; Pd, proneprhic duct. Embryos hybridized as whole mounts are shown in lateral view, with anterior to the left and dorsal to the top. Sections are in transverse orientation and shown with dorsal to the top. Stages of development are as indicated. The numbers of embryos represented by each panel, out of the number analyzed, are indicated in the top right corner. See also Figure S1 and Tables S1 and S2.
Image published in: Ciau-Uitz A et al. (2010)
Copyright © 2010. Image reproduced with permission of the Publisher, Elsevier B. V.
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