Gata family gene expression in AGM Gata2-dependent and -independent HPCs. (A) qRT-PCR for expression of Gata1, 2, 3, 4, 5, and 6 transcription factors (normalization with Gapdh) in E11 AGM CD31⁺cKit⁺Venus⁺ and CD31⁺cKit⁺Venus⁻ cells. n = 3. SEM shown with *P = .05 and ***P = .001. (B) Transverse section of WT E10.5 AGM immunostained for CD34 (magenta) and Gata3 (green) showing expression of Gata3 in the aortic endothelial cells and some emerging hematopoietic cells and ventral mesenchymal cells directly under the aorta. (C) Transverse section of G2V E10.5 AGM immunostained for CD34 (magenta), Gata2 (green), and Gata3 (red) showing some overlapping expression of Gata2 and Gata3 in aortic endothelial cells (arrowheads). (D) Transverse consecutive sections of E11 G2V AGM immunostained for CD34 (magenta) and Venus (green) in the top panels and for CD34 (magenta) and Gata4 (red) in the bottom panels. Gata4 expression is observed in some ventral aortic endothelial cells and emerging hematopoietic cells (arrow).