Extended Data Fig. 10: Collaterals in fetal human hearts.

a, Maximum intensity projection (MIP) of GW22 fetal human heart labeled with α-SMA, ventral side. bi, ROI of ventral side (blue boxed region). Closed orange arrows point to collateral segments. bii, Traced collateral connection (green filaments) on ventral side. ci, MIP of fetal human heart, dorsal side. cii, Traced collateral connections (green filaments) on dorsal side. d–f, MIP of entire fetal human GW14.5 (d), GW18.5 (e) and GW19.5 (f) hearts, ventral side. Scale bars, a–f, 1.5 mm.