Fig. 2: Lgr5⁺ villus tip telocytes are aligned with polarized villus tip vessels.

a, b Lgr5⁺-GFP villus tip telocytes (VTTs, yellow arrow) are distinct from Lgr5⁺ epithelial stem cells (white arrow) and are associated with villus tip blood vessels. Staining for VEGFR2 (red) and GFP (green). c VTT extensions are located between villus tip vessels and epithelial cells, the cell body is in the villus core. Staining for VEGFR2 (blue), GFP (green) and EpCAM (red). d Scheme of relative VTT density along the small intestine. VTTs are enriched in the proximal small intestine, corresponding to the zone with longest villus length and highest villus tip hypoxia (created with biorender.com). e Quantification of number of VTTs per villus in indicated intestinal regions; n = 3 mice. f VTTs are associated with high VEGFA signaling villus tip endothelial cells. Staining for PECAM1 (blue), VEGFR3 (red) and GFP (green). Quantification of percentage VTT associated with either VEGFR3⁺ or VEGFR3⁻ villus tip vessels of Lgr5-GFP-CreERT2 mice; n = 3 mice. L, lymphatic vessel. g VTTs drape cellular extensions over villus tip endothelial cell “open-faces”. Staining for VE-cadherin (red), ERG (blue) and GFP (green). h Workflow of fluorescence-directed serial block-face electron microscopy (SBEM) in Lgr5-EGFP-CreERT2 adult mice. i 3D reconstruction of a VTT derived from hand tracing across serial electron micrographs. j VTTs drape extensions between the villus tip vessel and the epithelium, while pericytes extend along the opposite villus core side of the vessel. 3D reconstruction of the villus tip from serial EM images of a Lgr5-GFP-CreERT2 mouse. Pseudo-coloring for VTTs (green), blood vessels (red), pericyte (blue), fenestrations (yellow). Epithelium, dotted line. k VTTs are separated from villus tip endothelial cells by a fibrillar extracellular matrix (dotted line). Single-electron micrograph section from SBEM images in (j), pseudo-coloring for an endothelial cell (red) and a VTT (green). Epithelium, dotted line. l, m VTTs and endothelial fenestrations are aligned. l Single-electron micrograph, VTT (green), endothelial fenestrations (arrowheads). m Magnification of the 3D rendering from (j); fenestrations (orange), endothelial filopodium (arrowhead). Whole-mount immunostaining was used to generate images a–c, f and g; electron microscopy-generated images i–m. Scale bars: 50 μm: a, b; 20 μm: c, f, g; 2 μm: k, l. All values shown as mean ± SD. Source data are provided as a Source Data file.