Blast cell colony development from WT (SIRT1^+/+) and SIRT1-deficient (SIRT1^−/−) ESCs. (A) Kinetics of blast and transitional colony development in SIRT1^+/+ and SIRT1^−/− EBs. Data are shown as mean ± SD. N = 3; *P < .01. Days (D) of differentiation are indicated. Δ = no colony grown. (B) fluorescence-activated cell sorting analysis of Flk1 and c-Kit expression on SIRT1^+/+ and SIRT1^−/− EB-derived cells. Days of differentiation are indicated. Numbers in each quadrant represent the percent of total population in each fraction. (C) Secondary EB colonies generated by SIRT1^+/+ and SIRT1^−/− EB cells. Days of differentiation are indicated. Data are shown as mean ± SD. N = 3; *P < .01. (D) Immunostaining and Dil-Ac-LDL uptake of adhesive cells generated from a single blast colony from SIRT1^+/+ and SIRT1^−/− EB-derived cells. VE-cadherin expression is indicated by green fluorescence and LDL uptake by red fluorescence. (E) Evaluation of the hematopoietic and endothelial potentials of BL-CFCs. The number of colonies that yielded secondary CFCs or adherent endothelial cells is divided by the total number of replated colonies. Bars represent SEM number from at least 3 experiments; *P < .01.