Fig. S6

Fli1a and Tal1 overexpression at 24 hpf is not sufficient to induce ectopic kdrl:GFP expression at 48 hpf. (A) Heat shock–induced etv2, fli1a, or tal1 are all capable of inducing ectopic kdrl:GFP⁺ cells in the early embryo. Kdrl:GFP embryos were injected with the indicated heat shock–inducible transgenes, heat shocked at shield stage, and imaged at 16 somite stage. Nuclear mCherry (NLS-mCherry) was not able to induce ectopic kdrl:GFP while etv2, fli1a, and tal1 were (bracketed area in lateral view of embryo). The number of embryos exhibiting ectopic GFP expression over the total number observed is represented in the top right corner of each panel. (B) Kdrl:GFP transgenic embryos were injected with hsp70l:etv2, hsp70:fli1a, or hsp70:tal1 transgenes and heat shocked at 24 hpf. Each transcription factor was labeled with mCherry and expression was confirmed by imaging 3 h post–heat shock (inset). GFP expression was imaged at 48 hpf. Etv2 overexpression resulted in strong ectopic GFP expression, but neither Fli1a nor Tal1 was sufficient for inducing the same response. The ratio in the bottom right corner of each panel represents the GFP positive embryos over the total observed.