Figure 6.

Chamber precursor morphogenesis in EMLOCs

(A) Cartoon schematic of a developing heart tube. Chamber wall layers are expanded to depict myocardium, extracellular matrix-rich cardiac jelly, and endocardium interior lining.

(B) 3D reconstruction of the anterior cardiac chamber-like structures with cTnT+ myocardium (magenta) and Laminin+ interior (top-left). Single Z-slice multi-dimensional view of chamber (top-right). High magnification images are provided below.

(C) VCAN, ADAMTS1, ANGPT1 genes involved in cardiac jelly and its spatiotemporal degradation in day 16 EMLOC by scRNAseq, visualized using PHATE.

(D) Immunofluorescence of cTnT, GATA4 and DAPI demonstrating putative outflow tract (white arrows) in two day 7 EMLOCs. Z-slice inset provides a second example.

(E) Immunofluorescence of N-Cadherin (CDH2, cyan), VE-Cadherin (vascular endothelial cadherin/CD144/CDH5, magenta), and DAPI (gray) depicting endothelial biomarker expression lining the putative outflow tract. Individual scale bars provided.

(F) Biomarkers for smooth muscle cells (CNN1/TAGLN) and the outflow tract (ISL1/PDE5A/CDH11) along with vascular endothelial cells (KDR/FLT1/ESAM/CDH5) (cluster 9).

(G) POSTN, TBX3, NPR3, NFATC4 genes involved in atrioventricular valve formation.