Fig. 2. Tie2-Cre-mediated c-myc deletion results in anemia, vascular defects and lethality. (A-F) Live embryos in yolk sac dissected at 9.5 dpc (A,B), 10.5 dpc (C,D) or 11.5 dpc (E,F). (G-L) Anti-CD31-stained whole-mount yolk sacs (G,H) and heads (I-L) at 11.5 dpc. Vasculature in the mutant is less developed with reduced caliber and number of branches. Scale bar: 200 µm. (M,N) Efficient c-Myc deletion by Tie2-Cre did not increase N-Myc expression in 10.5 dpc primary ECs. The percentage of c-Myc-positive ECs is indicated in M. The percentage of N-Myc positive ECs is shown in N. `n' represents the number of cells counted in each assay. (O) Peripheral blood cell counts at 10.5 dpc from control (n=19) and Tie2-Cre;c-myc^flox/- mutant (n=7) embryos. The numbers above the brackets show the fold decrease in the mutants compared with controls. ^*P<0.01; ^**P<0.05 by Student's t-test.