Restoration of RA signaling in RA-deficient embryos rescues hematopoietic potential and function of hemogenic endothelium. (A) qPCR analysis of endogenous hematoendothelial gene expression in RA-treated E9.5 Raldh2^−/− versus WT littermate yolk sacs. All data were calculated as gene expression relative to endogenous β-actin expression of the tissue (n = 3). (B) Hematopoietic potential of RA-treated E9.5 Raldh2^−/− mutant versus WT littermate yolk sac in vitro. All data were calculated as the number of individual colonies generated per 1000 viable seeded cells plus or minus SEM (n ≥ 3).