Fig. 5. PLXN–SEMA signalling mediates the migration of trabecular vCMs.

a, NLS-mKATE2⁺ non-trabecular and GFP⁺ trabecular-like hPSC-vCMs were bioprinted into multilayered constructs modelling the ventricular wall as shown in the diagram. b, GFP⁺ trabecular-like hPSC-vCMs migrate to the intermediate ventricular-like layer (Int.-LV), which contains NLS-mKATE2⁺ non trabecular-like hPSC-vCMs mixed with SEMA3C but not when mixed with SEMA3D, SEMA6A or SEMA6B. White arrows point to GFP⁺ trabecular-like hPSC-vCMs migrating into the intermediate ventricular-like layer. c, SEMA6A or SEMA6B mixed in different combinations in the intermediate ventricular-like layer prevented SEMA3C-mediated GFP⁺ trabecular-like hPSC-vCM migration. White arrows point to GFP⁺ trabecular-like hPSC-vCMs migrating into the intermediate ventricular-like layer. d, GFP⁺ trabecular-like hPSC-vCM migration measurements under different intermediate-LV CC-like layer conditions. N = 6 and N = 5 independent experiments for SEMA3C+SEMA3C and no SEMA+SEMA3C conditions, respectively. N = 3 independent experiments for all other conditions. Error bars are s.e.m. e, Representative sections of hearts from E17.5 wild type (WT) and Tcf21-creERT2;Sema3c^fl/fl knockout (KO) mouse embryos show that deletion of Sema3c in Tcf21⁺ cells starting at E10.5 leads to a cardiac ventricular wall non-compaction phenotype. f, Graphs show the thickness of the compact and trabecular myocardium in WT and conditionally deleted Sema3c KO mouse hearts. N = 3 mice per condition. Error bars are s.e.m. g, Model shows how PLXN–SEMA interactions among distinct vCMs, fibroblasts and endothelial cells coordinate the organization of vCMs within the ventricular wall. White dashed lines in b and c outline the intermediate-LV CC-like layer. P values in d and f determined by one-way analysis of variance. NS, not significant. Scale bars, 100 µm (b,c) or 250 µm (e). Schematic in a adapted from ref. ⁴¹, Elsevier.

Source Data