Activity of the Flk-1 promoter/enhancer in vivo.

(A) Direct fluorescent image of a 10-dpc mouse embryo transgenic for a reporter gene construct in which the GFPgene is under the control of the Flk-1 promoter/enhancer. (B) Expression of VE cadherin (top row) and GFP in CD45⁻, Ter119⁻ (bottom row), and GFP and hematopoietic markers in cells dissociated from 10.5- and 12.5-dpc transgenic mouse embryos. The result shown is a representative of 3 independent experiments for 3 independent clones. (C) Morphology of hematopoietic and PECAM⁺ endothelial colonies generated from either GFP⁻ endothelial cells obtained from 10.5-dpc transgenic embryos. Original magnification ×100.