Both hif-1α and hif-2α function in EHT. (A) qPCR analysis of runx1 and cmyb mRNA levels in 36 hpf controls, hif-1α^−/−, hif-2α^−/−, and hif-2α MO-injected hif-1α^−/−. Values represent mean plus standard deviation (SD) (n = 3 biological replicates). Ct values for each gene in WT samples: rpl13 = 18.11; runx1 = 27.87; cmyb = 25.81. (B-E) Brightfield images of WISH for runx1/cmyb expression in 36 hpf (B-C) control MO-injected hif-1α^−/− and (D-E) hif-2α MO-injected hif-1α^−/− in normoxia and after hypoxia exposure for 8 hours starting at 28 hpf (lateral views). Scale bar, 100 μm. *P < .05; **P < .01 (Student t test).