Schematic drawing of cell clusters that comprise germ layers, organs, and tissues of gastrulae and larvae
Comparison of gene expression in stomodeum formation region between ambulacrarian and chordate larvae
(A) Expression profiles of development-relevant genes in the stomodeal (mouth opening) region. The stomodeum is formed by stomodeal ectoderm (orange), stomodeal endoderm (blue) and oral endoderm (green). Most of genes expressed in these regions are major component genes of vertebrate Spemann’s organizer. (B) (Left) Gene expression pattern of chordate dorsal structures (notochord + floor plate), and (right) that of starfish larval stomodeum, transverse section of dotted line of (A). This suggests the ambulacrarian stomodeum plays a role of vertebrate Spemann’s organizer.
UMAP plot for clustering of embryonic cells obtained by single-cell RNA-seq analyses
Based on shared expression profiles of transcription factor genes and cellular signaling molecule genes, constituent cells of starfish embryos and larvae can be categorized into 22 clusters, numbered 0 to 21. Each dot represents each cell.