Figure 5. ETO2 Regulates HSC Development through VEGFA170(A) Vegfa expression is downregulated (top right panel) or absent (bottom right panel) in the somites of stage 27 Eto2 morphants (red arrowheads) but maintained in the hypochord (yellow arrowheads), as revealed by ISHS (transverse sections with dorsal to the top).(B) WMISH staining time course reveals downregulation of Vegfa in Eto2 morphant somites; the staining is markedly lighter in morphant embryos at 8 and 11 hr after addition of the staining substrate (anterior to the left, dorsal to the top).(C) Alternative splicing generates VEGFA isoforms with different biological properties. In X. laevis, there are three known VEGFA isoforms (VEGF122, VEGFA170, and VEGFA190). FLK1, FLT1: binding domains for receptors. The C-terminal domain of isoforms VEGFA170 and VEGFA190 is responsible for association with the extracellular matrix (ECM) and the cell membrane. VEGF122 is the diffusible isoform (Cleaver and Krieg, 1998).(D) Levels of isoform-specific VEGFA transcripts in WT and Eto2 morphant somite-hypochord regions at stage 27 (n = 5) quantitated by qPCR. Error bars denote SEM. ∗p < 0.05.(E) Exogenous Vegfa170 expression rescues the HSC program in Eto2 morphants. Embryos were coinjected with Eto2-MO only or Eto2-MO and 4 ng of mRNAs encoding Vegfa122or Vegfa170 isoforms. Rescue of Runx1 and Gfi1 expression in DA (WMISH, red arrowheads) was observed only with Vegfa170 mRNA. Pos, positive; neg, negative. Whole mounts are shown with anterior to the left; dorsal at the top.See also Figure S5.
Image published in: Leung A et al. (2013)
© 2013 ELL & Excerpta Medica. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution license
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