Extended Data Fig. 2. Annotation and clustering of integrated heart samples was carried out over several resolutions.

Integrated adult and fetal data were iteratively clustered by aggregating high-resolution sub-clusters as shown in a, uniform manifold approximation and projection (UMAP) embeddings showing i, 10 initial low resolution clustering followed by; ii, sub-clustering, and iii-iv, aggregation of biologically similar cell clusters over two intermediate resolutions. Sub-clustering of low-resolution clusters depicted with; b subcluster UMAPs illustrating the identification of cell types and states using previous adult annotations, cell sources, and unsupervised clustering.