Fig. 4. Arteries are linked to initial HSC and HSPC engraftment in fetal BM.

a Overview and high-magnification representative images showing close alignment of Lin⁻ CD48⁻ CD41⁻ CD150 ⁺ HSC (green, arrows) and Caveolin-1⁺ AECs (red) at E16.5. Blue, Lin⁺ CD48⁺ CD41⁺. White box in left panel indicates position of high magnification images. b 3D-reconstructed image showing CD150⁺ cells (green) and Caveolin-1⁺ arteries (red). c 3D-reconstruction-based quantification of distance between HSCs (N = 48), Lin⁺ CD48⁺ CD41⁺ mature haematopoietic cells (N = 2203) or DAPI⁺ random cells (N = 6174) and Caveolin-1⁺ AECs at E16.5. P-value, Kolmogorov-Smirnov test. d Representative images showing close alignment of c-Kit⁺ haematopoietic cells (green) and Caveolin-1⁺ AECs (arrows, red) at E16.5. CD31, blue. e Representative 3D-reconstructed image showing location of c-Kit⁺ haematopoietic cells (green) and Caveolin-1 (red). f 3D-reconstruction-based quantification of distance between c-Kit⁺ (N = 258), Lin⁺ CD48⁺ CD41⁺ mature haematopoietic cells (N = 2052) or DAPI⁺ random cells (N = 6665) and Caveolin-1⁺ AECs at E16.5. P-value, Kolmogorov-Smirnov test. g Violin plots showing expression of selected genes encoding angiocrine or HSPC-supportive factors in AECs or other EC subclusters at E18.5 with log normalized values (y axis). h Interactome analysis of potential interactions (arrows) between multipotent HSPCs and different ECs subclusters. Width of line and arrow represent relative expression level of genes.