Fig. 1

Compound screening for activation of atrial and ventricular reporter genes. a Screening strategy for identification of cardiogenic compounds during the spontaneous differentiation of reporter mESCs. GATA4-targeted compounds were screened during a D2–D10 window encompassing mesodermal commitment, cardiac progenitor specification, and differentiation of spontaneously beating cardiomyocytes. Differentiation cultures were measured on D12 of differentiation after treatment with GATA4-targeted compounds for b %venGFP+ cells and c venGFP-MFI. Pluripotent stem cells (PSCs), cardiomyocyte (CM), atrRFP (SMyHC3-TdTomato, atrial), venGFP (Myl2-eGFP, ventricular), all-trans retinoic acid (ATRA), and mean fluorescent intensity (MFI). Data is presented as mean ± SEM (n ≥ 3, independent experiments). ****P ≤ 0.0001, ***P ≤ 0.001, **P ≤ 0.01, *P ≤ 0.05 (T test or Wilcoxon vs DMSO control). n = 3 (3i-1000 300 nM, 3i-1194 10 μM, 3i-1194 15 μM, 3i-1165 10 μM, 3i-1165 30 μM), n = 4 (3i-1103 1 μM, 3i-1236 5 μM, 3i-1236 10 μM), n = 5 (3i-1047 3 μM, 3i-1103 3 μM, 3i-1148 5.5 μM), n = 7 (3i-1103 5 μM), n = 8 (3i-1047 10 μM), n = 10 (ATRA 10 μM), n = 11 (3i-1000 1 μM), n = 13 (ATRA 2.5 μM), n = 21 (3i-1000 5 μM), n = 26 (3i-1000 3 μM)