Cell Stem Cell, Volume 2 Supplemental Data ER71 Acts Downstream of BMP, Notch, and Wnt Signaling in Blood and Vessel Progenitor Specification Dongjun Lee, Changwon Park, Ho Lee, Jesse J. Lugus, Seok Hyung Kim, Elizabeth Arentson, Yun Shin Chung, Gustavo Gomez, Michael Kyba, Shuo Lin, Ralf Janknecht, Dae-Sik Lim, and Kyunghee Choi Figure S1. (A) Sequence of the promoter of Flk1 used for the luciferase assay. Nine boxes indicate potential Ets binding sites (4 red in sense and 5 blue in anti-sense). T in green box indicates transcriptional start site (based on the numbering by Ronicke et al., 1996). (B) ER71 can activate Flk1 gene in a dosage dependent manner. RNA from MS1 endothelial cells transfected with control or ER71 were analysed by RT-PCR with the indicated oligos. Numbers indicate the relative ratio of band intensity. Er71: forward-5’- GGGGGATTCCAGGACTGCAGCATCCCTTTCG-3’, reverse-5’- GGGGAATTCGAAGCGGTATGTGTACTTGCG-3’, Vegfr2 (Flk1): forward-5’- TACACAATTCAGAGCGATGTGTGGT-3’, reverse-5’- CTGGTTCCTCCAATGGGATATCTTC-3’ (Hamada et al., 2005), β-actin: forward-5’- ATGAAG ATCCTGACCGAGCG-3’, reverse-5’-TACTTGCGCTCAGGAGGAGC-3’ (Kubo et al., 2004). Figure S2. (A) H & E staining of transverse section of E9.0 and E9.5. Mutant embryos show lack of endocardium and disorganized myocardium. The boxed area is shown at higher magnification. DA, dorsal aorta; He, heart; NT, neural tube. Scale bar; 50 µm (B) H & E staining of sagittal section of E9.0. SM; somites. Scale bars; 50 µm. (C) Whole-