Fig. 1: Single-nuclei RNA sequencing of fetal SAN tissue identifies markers of Core SAN pacemaker cells.

a Schematic overview of SAN tissue dissection and processing for snRNA-seq on the 10x Genomics Chromium platform. b Uniform manifold approximation and projection (UMAP) of gestation week 19 fetal heart SAN tissue sample showing 19 cell clusters (left). Subclustering of the TNNT2+ cardiomyocytes showing 8 sub-clusters (right). c UMAPs of the subclustered cardiomyocytes showing the expression of the indicated genes. d Heatmap of the top 5 differentially expressed genes (DEGs) within the indicated cardiomyocyte subclusters. e Gene Ontology (GO) analysis (biological processes) of all genes enriched in the Core SAN cluster. f UMAPs showing the top 10 DEGs of the core SAN cluster. Schematics in (a) were generated using Biorender (https://biorender.com).