Extended Data Figure 5: Focused analyses of myocardial populations and spatial validation of right ventricle markers.
a, UMAP plot of reclustered “Myocardium” population colored by cluster and embryonic stage of collection. b, Heatmap of highly and uniquely expressed genes in myocardial subpopulations. Scale indicates Z-scored expression values. Statistics for differential gene expression tests were applied to n=6,474 cells. c, UMAP plot of reclustered ventricle populations colored by cluster and embryonic stage of collection. d, Heatmap showing curated list of genes that identify left ventricle (LV), right ventricle (RV) and early RV progenitors. Scale indicates Z-scored expression values. Statistics for differential gene expression tests were applied to n=1,976 cells. e, mRNA expression of left ventricle marker Hand1 (green) and Pln (red) in frontal view of the E9.5 heart showing enrichment in right ventricle region by whole mount in situ hybridization. n=2 independent embryos per gene, Scale bar, 200 μm. f, Breeding scheme for lineage-tracing Cck expressing cells. g, mRNA expression of endogenous Cck and TdTomato driven by Cck-cre transgene at E9.25 in right oblique view of the heart. n=2 independent embryos per gene; scale bar, 200 μm. h, Expression of TdTomato in whole-mount and sectioned postnatal day 1 (P1) heart from Ai14xCck-cre lineage-traced mice showing location of progeny of Cck-expressing cells. Left panels show brightfield view (top) or TdTomato (bottom) of whole-mount P1 heart; right panels show sections of TdTomato and DAPI (top) or TdTomato alone (bottom) in P1 heart section. n=2 independent embryos. Scale bar, 100 μm. EMP, early myocardial progenitors; SV, sinus venosus; A, atria; AVC, atrioventricular canal; OFT, outflow tract; V, ventricle; RV, right ventricle; LV, left ventricle; IVS, interventricular septum.