心脏腔室的趋同进化：从原始管状心脏到多腔结构的演化机制

The independent emergence of atrial chambers from primitive tubular hearts in both protostomes and deuterostomes represents a notable case of convergent evolution. Although mammalian chamber formation has been extensively studied from developmental perspectives (48, 49) and cellular signatures of human fetal heart chambers have been recently characterized (27), the evolutionary-scale cellular signatures distinguishing atria from ventricles remain unexplored, a crucial gap in understanding chamber evolution. Using spatial omics data from maximal longitudinal heart sections across 14 species (fig. S27A) representing tubular and two-, three-, and four-chambered hearts, we analyzed cellular composition during chamber evolution. The chamber anatomical positions of atria and ventricles were defined according to acid fuchsin-orange G (AFOG) staining (figs. S1, B and C, and S27A). …