High-resolution atlas of the developing human heart and the great vessels

The human heart and adjoining great vessels consist of multiple cell types vital for life, yet many remain uncharacterised molecularly during development. Here, we performed a high-resolution profiling of the heart and great vessels during the first and second trimesters, defining 63 cell types with distinct identity and location-specific signatures. We reveal previously unreported cell types, including for the pericardium and the ductus arteriosus. At the ventricles, we identified signatures involved in establishing the trabeculation-compaction and right-left axes of ventricular cardiomyocytes. At the vessels, we distinguished the constituents belonging to either coronary or great vessels. We confirmed our findings and revealed nuanced signatures with specific zonation patterns. Collectively, we provide a comprehensive human cardiac developmental atlas for enhanced understanding of function in health and disease. ### Competing Interest Statement S.A.T. is a scientific advisory board member of ForeSite Labs, Qiagen and Element Biosciences, and a co-founder and equity holder of TransitionBio and EnsoCell Therapeutics. S.S. is a co-founder and equity holder of ABS Biotechnologies. The remaining authors declare no competing interests.