VBI excision causes a loss of blood markers, whereas EC markers appear unaltered. (A) Schematic of the VBI region excision and subsequent embryo culture. After culturing to tailbud, control and manipulated embryos were assayed by in situ hybridization using the probes indicated in the panels. All manipulated embryos are labeled as ΔVBI. (B-K) Excision of the VBI eliminates expression of hematopoietic markers in the embryo. (B′-G′) Ventral views of the blood island region. (L-W) Excision of the VBI produces no consistent alteration in the pattern or intensity of the embryonic endothelium. Proportion of embryos displaying the in situ pattern illustrated is presented at lower right of each panel. (X-Y) Explant tissues at equivalent of st34, stained for blood (hba1) and endothelial (aplnr) differentiation markers, respectively. Note the absence of positive staining for the endothelial marker. Scale bar is 100 μm.