Fig. 1

FHF/SHF-like cells are induced in spheroid PSC culture. a Live imaging of Hcn4-GFP, Tbx1-Cre, Ai9 mice E8.0. GFP is exclusively expressed in the cardiac crescent and primitive myotube, whereas RFP is expressed in the posterior region. b Live imaging of Hcn4-GFP, Tbx1-Cre, Ai9 mice E9.0. GFP expression is restricted to the LV and atria whereas RFP is expressed in the pharyngeal region posterior to the heart, the outflow tract and RV. c Schematic of the strategy used to generate and differentiate ESC-derived cardiac spheroids. d Flow cytometric analyses of Hcn4-GFP⁺ and Tbx1-Cre, RFP⁺ in cardiac spheroids after 5.5 days of differentiation. e Flow cytometric analyses of GFP⁺/cTnT⁺ and RFP⁺/cTnT⁺ cells at day 9 in cardiac spheroids. f Representative images from live imaging time-lapse experiments of a differentiating cardiac spheroid. White scale bars indicate 100 μm