(A and B) Day 8 differentiated ES cell cultures were reacted with the PECAM antibody, and representative areas were analyzed for vessel area (A) or branch point frequency (B)

(A) The mean vessel area of all rescue clones was significantly different from WT and mutant clones ( vs. sFlt and mFlt, P ≤ 0.0005; WT vs. sFlt and mFlt, P ≤ 0.02) but did not differ between sFlt-1 and mFlt-1 rescue clones (sFlt vs. mFlt, P = 0.86). (B) The mean branch points/millimeter vessel length was significantly different between sFlt-1 and mFlt-1 rescue clones (sFlt vs. mFlt, **, P ≤ 0.03). Branch points/millimeter vessel length was not significantly different between mutant and mFlt clones ( vs. mFlt, P = 0.97; WT vs. mFlt, P ≤ 0.01). Branch points/millimeter vessel length was significantly different between mutant and sFlt isoform clones ( vs. sFlt, P ≤ 0.01; WT vs. sFlt, P = 0.16). Error bars represent SEM.Copyright information:Taken from "The VEGF receptor Flt-1 spatially modulates Flk-1 signaling and blood vessel branching"The Journal of Cell Biology 2008;181(5):847-858.Published online 2 Jun 2008PMCID:PMC2396811.