Chemically induced hypoxia in wild-type embryos by DMOG partly mimics the vhl hypoxic phenotype. (A) o-Dianisidine stainings and (B) whole-mount in situ hybridizations for phd3, ndufa4, βE1 globin, vegfa, epo, and epor on 7 dpf wild-type embryos treated for 4 days with 0.1% DMSO (control, left column) or 100 μM of the nonspecific PHD/FIH inhibitor DMOG (middle column). Compared with age-matched vhl mutants (right column), DMOG-treated embryos develop a similar molecular hypoxic response and an increased number of βE1 globin⁺ blood cells; however, expression levels are generally somewhat lower and vhl^−/− expression of phd3/ndufa4 in the heart, vegfa/epo in the liver, and epo in the glomerulus was not observed in 100 μM DMOG-treated embryos. In addition, DMOG-treated embryos show strong vegfa expression in the proximal renal tubule, which is not apparent in vhl mutants. (C) Unlike vhl mutants, May-Grünwald-Giemsa–stained blood smears of 0.1% DMSO and 100 μM DMOG-treated wild-type embryos reveal blood cells of normal maturation. Original magnifications, ×5 (A,B) and ×40 (C).