Fig. 1: Integrated analysis of human limb buds and embryonic long bones.

a Representative stereoscope images (left) and H&E images (right) of 5 WPC human limb bud and 8 WPC human long bone (n = 2 embryos). Scale bars, 100 μm. b Sampling workflow and experimental scheme. Human embryonic cells from 5 WPC limb buds and 8 WPC long bones were sorted and subjected to droplet-based scRNA-seq. c Distribution of 35,570 cells from limb buds and long bones. In total, 16 subsets were visualized by uniform manifold approximation and projection (UMAP). d Dot plots showing the expression of curated feature genes in 16 subsets. Dot size represented the proportion of cells expressing specific gene in the indicated subset and color bar represented the gene expression levels. e Proportion of cells from 5 WPC limb buds and 8 WPC long bones in each subset. f Developmental trajectory inferred by RNA velocity and visualized on the UMAP projection. g Partition-based graph abstraction (PAGA) showing the connectivity among subsets in f. The mean expression of representative genes (Mesenchymal, PRRX1; Chondrogenic, SOX9; Osteogenic, RUNX2) in each subset was shown in abstracted graph. Line thickness indicated the strength of connectivity. Color bar represents the gene expression levels.