Extended Data Fig. 3: Ventricular and atrial cardiomyocytes.

a, Expression (log₂FC) of selected marker genes in ventricular cardiomyocyte subpopulations. b, Expression (log₂FC) of selected marker genes in atrial cardiomyocyte subpopulations c, Single channel multiplexed smFISH images of overlay shown in Fig. 2c, d, g, h. d, Expression (log₂FC) of specific markers in cardiomyocyte subpopulations. I and II, PCDH7 expression in ventricular and atrial cardiomyocytes, respectively. III, PRELID2 expression is highest in vCM2 and is enriched in right ventricles. IV and V, CNN1 expression is enriched in both vCM3 and aCM3. VI and VII, HAMP expression is enriched in the right atrium. e, Multiplexed smFISH of transcripts enriched in cardiomyocyte subpopulations. Left, expression of TNNT2 (green) and PCDH7 (red) in left ventricles. Right, expression of TNNT2 (green) and CNN1 (red) in right ventricles, nuclei are DAPI-stained (dark blue). Scale bars, 10 μm. f, Gene Ontology analysis results for vCM4 showing significant terms related to energy metabolism and muscle contraction. Data are available in Supplementary Table 6. g, Multiplexed smFISH of positive and negative RNAscope control probes. Scale bars, 5 μm. For details on statistics and reproducibility, see Methods.