Postnatal heart development is coordinated by multi-lineage Wnt and BMP signaling.
Early postnatal heart growth requires a transition from cardiomyocyte proliferation to enlargement and binucleation. Using morphometric, transcriptomic, signaling, and single-cell analyses in neonatal mice, we show that this transition occurs predominantly between postnatal day 3.5 and 4.5 (P3.5-P4.5), accompanied by d...