CoCl₂ induces abnormal neovascularization in zebrafish embryos.

<p>(A) Morphological images obtained by an optical microscope revealed no severe phenotype in CoCl_<b>2</b>-treated Tg(<i>fli1a</i>:<i>EGFP</i>) embryos at 3 dpf. (B) With fluorescence excitation, ectopic SIV and excessive retinal vascularization are shown in CoCl_<b>2</b>-treated embryos compared with the untreated control. (C, D) A dose-dependent decrease in survival rates (four independent experiments; n = 35 in each group) in embryos treated with increasing concentrations (0–20 mM) and an increase in the vascular defect occurrence rate in the SIV and retinal vessels are shown (three independent experiments; n = 35 in each group). (E, F) Real-time RT-PCR data show that CoCl_<b>2</b> treatment causes overexpression of <i>vegfaa</i> and <i>vegfr2</i> mRNAs in zebrafish. (G,H) Absolute quantification of the copy number of <i>vegfr2</i> and <i>plxnd1</i> by real-time PCR are reduced at 5 dpf versus 3 dpf. Each bar represents the mean ± SEM. * (<i>p</i> < 0.01) and ** (<i>p</i> < 0.001) compared with the mock control group. SIV, subintestinal vessel; RV, retinal vessel.