Fig. 4: Central vein is a primary source of nascent lobule vasculature at the periphery of the liver.

a Schematic summary of the experimental design to assess central vein-derived clonal expansion. b–b”, Apelin^CreERT2; Confetti thick liver section immunostained for GFP and RFP to mark the clones at 8 weeks. The dotted line delineates the periphery. c Quantification of Apelin^CreERT2; Confetti clone size measured as the number of cells per clone in the periphery compared to the core in 8-week-old mice. n = 70 clones in the core and n = 30 clones in the periphery from 3 mice were scored. Red bars represent the mean values. Welch’s t-test, p-value = 0.0108. d Schematic summary of the experimental design to assess central vein-specific lineage tracing. e Apelin^CreERT2;mTmG thick liver section immunostained for GFP to visualize the early labeling at 1 week. f–f”’, Apelin^CreERT2;mTmG thick liver section immunostained for GFP and EPCR to visualize the tracing at 8 weeks. Dotted line delineates the periphery. Arrows in (f) show two neighboring lobules with dramatically different amounts of expansion. Arrows in (f”) and (f”’) show labeled cells within portal veins. g–g’ Apelin^CreERT2;mTmG thick liver section taken from the left lobe immunostained for GFP and EPCR at 8 weeks. Dotted line in (g’) delineates the lobule boundaries. h Quantification of central vein-derived expansion in 8-week-old Apelin^CreERT2;mTmG livers in the periphery compared to the core. n = 3 mice, mean values ± s.d. Ratio paired t test, p-value = 0.0290. i Representative Apelin^CreERT2;mTmG thick liver section immunostained for GFP and the sinusoidal marker Lyve1 to visualize the outcome of tracing in sinusoids. Dotted line delineates the lobule boundaries. j Cross-slice of iDisco-cleared Apelin^CreERT2;mTmG whole lobe immunostained for GFP and EPCR. Dotted line delineates lobule boundaries. j’ Cartoon representation of lobule and non-lobule arrangements. Central vein lineage tracing outcome is not represented for clarity. DAPI in blue depicts nuclei. tam, tamoxifen. CV, central vein. PV, portal vessel. Source data are provided in the Fig. 4 Source Data file.