Single Cell Approaches to Understand the Earliest Steps in Heart Development

Purpose of Review Cardiac progenitors are the building blocks of the heart. Our knowledge, on how these progenitors build the heart, has considerably increased over the last two decades with the development of single cell approaches. We discuss the lessons learnt from clonal analyses and from single cell sequencing technologies on the understanding of the earliest steps of cardiac specification and lineage segregation. Recent Findings While experiments were initially performed at the population level, the development of approaches to investigate heart development at the single cell resolution has clearly demonstrated that cardiac progenitors are highly heterogeneous, with different progenitors contributing to different cardiac regions and different cardiac cell types. Some critical transcriptional determinants have also been identified for cardiac progenitor specification. Summary Single cell approaches have finally provided insights into the spatio-temporal specification of unipotent and multipotent cardiac progenitors and provided a framework for investigating congenital heart defects.