Fig. 3: Molecular map of CPCS development.
From: Spatiotemporal gene expression and cellular dynamics of the developing human heart
a, UMAPs displaying seven coarse-grained and 19 fine-grained CM clusters, representing a range of contractile CMs of ventricular (vCM_1–6) and atrial origins (Left_aCM, Right_aCM and Cond_aCM aligning with smooth-walled conduit atrial regions), cell states of lower maturation levels (Immat_CM_1–3) and with cell cycle signature (Prol_CM_1–2) as well as components of the CPCS. b, Feature plots of MYH7 and MYH6 outlining ventricular and atrial identities, respectively. c, CM components of the CPCS with characteristic markers and predicted localization in an 11 PCW heart section. d, Heatmap visualizing per-gene scaled expression of transcription factors and axon guidance molecules in SAN_CMs and AVN_CMs, and mature contractile atrial CM populations (left). Spatial enrichment of these genes in sinoatrial and atrioventricular node regions is presented in a 6.5 PCW heart section by ISS (right). e, Heatmap illustrating per-gene scaled expression of CPCS marker genes in AVN-BB_CMs, PF_CMs, TsPF_CMs and vCM_4 cells, characterized by the highest maturation state among contractile ventricular CM clusters (left). Spatial expression patterns of these genes detected by ISS in a 9 PCW heart section, corroborating their association with the proximal and distal ventricular conduction system (VCS) (right). f, Dot plot featuring relative expression of selected ion channels in SAN_CMs and AVN_CMs compared to contractile atrial CM clusters (upper left). Illustration of ion currents of the nodal cell action potential (upper right). Spatial pattern of HCN and T-type Ca2+ channel transcripts in 6.5 PCW and 9 PCW heart sections, detected by ISS (lower). g, Gene regulatory network of SAN_CMs, including the top ten differentially expressed transcription factors compared to all other CM states and their associated target genes. la, left atrium; ra, right atrium; rv, right ventricle; ao, aorta; If, funny current; ICaT, T-type calcium current; ICaL, L-type calcium current; IK, delayed rectifier potassium current; IKACh, acetylcholine-activated potassium current.
