The color legend for the UMAP plots is displayed in ( g ). g Bar graph showing the macrophage subtype percentages at each regeneration stage as determined by scRNA-seq. h Dimensionality reduction of fibroblast subpopulations analyzed by scRNA-seq (top) and spatial visualization domain 12: FB (reg.) by Stereo-seq (bottom), respectively, across all regeneration stages. i Fluorescence in situ hybridization staining with col12a1a (green), lum (red) and DAPI (blue) in uninjured or regenerating hearts at 7 dpa ( n = 4 sections from 4 hearts for each time point). Arrowheads indicate co-located signals. Scale bars: 100 μm. j UMAP showing the subclusters and the RNA velocity of fibroblast as determined by scRNA-seq.