Extended Data Fig. 1: Transcriptomic Profiles and Temporal Transitions of Cardiac Spatial Clusters.

A. Dot plot depicting the top 5 DEGs (log₂FC > 0, P < 0.05) in the 23 spatial clusters in the developing heart. Genes highlighted by dashed rectangles were selected for spatial expression plots included in Extended Data Fig. 1E. Avg. exp., average expression; Pct. exp., percent of expressing cells. B. Localization of spatial clusters in the developing heart, presented in a 10 PCW heart section. The cluster corresponding to the early outflow tract (OFT) is absent in this sample. C. UMAPs illustrating changes in distribution of tissue spots between spatial clusters across three developmental age groups (6-7.5, 8-9, 10-12 PCW, each age group downsampled to 2,649 spots). D. Temporal evolution of outflow tract- and great artery-related spatial clusters, presented in 6, 8 and 10 PCW heart sections. The cluster corresponding to the early outflow tract (OFT) gradually disappears, while the one representing the tunica media of great arteries (TM) expands during this period. E. Spatial feature plots displaying selected DEGs (log₂FC > 0, P < 0.05) of spatial clusters in a 10 PCW heart section.