Cardiovascular and EMT transcription factors regulated by Mesp1 in early MCPs. (A and B) Real-time RT-PCR analysis of mRNA relative expression of cardiovascular (A) and EMT (B) transcription factors in FACS-isolated Mesp1-GFP cells at D3 (black bars). Results are normalized for the transcript expression in Mesp1-GFP–negative (Neg) cells (white bars). (C) E-Cadherin expression in all cells and in Mesp1-expressing cells as measured by FACS. (D) Real-time RT-PCR analysis of the expression of cardiovascular transcription factors in CXCR4/PDGFRa/Flk1 TP cells isolated at D3 (white bars) and D4 (black bars). Results are normalized for the mRNA expression in CXCR4⁻/PDGFRa⁻/Flk1⁻ cells. Numbers at the top of the bars indicate the fold change. (E) Real-time RT-PCR analysis of the expression of cardiovascular transcription factors within the TP population in Dox-inducible Mesp1 ESCs isolated at D4 in the presence or in the absence of Dox for 48 h. Results are normalized for transcript expression in unstimulated TP cells. (F) RT-PCR analysis of cardiovascular transcription factor expression in single TP isolated cells from Mesp1-inducible ESCs in the presence or in the absence of Dox for 48 h. Only clones positive for β-actin are shown, with dividing lines indicating the removal of intervening lanes from the gels. Samples tested in different experiments are shown as distinct panels with their respective positive (+) and negative (−) control samples. (G) Expression of cardiovascular transcription factors in Dox-inducible EN-Mesp1 ESCs at D3. Results are normalized for the expression in Dox-untreated cells. Error bars indicate means ± SEM (n = 3).