MDS-derived changes in mice stromal compartment from xenograft transplantation experiments. (A) Schematic workflow of transplantation setup: MDS- and HY-derived CD34⁺ cells were injected alongside in vitro expanded MSCs into NSG mice after busulfan conditioning. End point analysis was conducted at 24 to 29 weeks after transplant. (B) Quantified engraftment of n = 18 MDS and HY mice who underwent xenograft transplantation at end point; 2-sided t test. (C) Quantification of % CD51⁺CD140a⁺ double-positive cells from pooled mouse bones per sample donor as percent of murine lineage-negative cells. CTRL mice did not receive xenotransplantation; 2-sided t test. (D) UMAP clustering of n = 13 487 high-quality cells mapped to mouse (mm10) genome to identify stromal and residual hematopoietic cell populations. (E) Differential abundance of detected cell populations quantified as odds ratio for MDS vs HY sample origin. Positive ratio indicates increased abundance in MDS samples. (F) Gene expression of aggregated gene expression for Kitl, Il7, Igf1, Csf1, Bmp4, and Cxcl12 across CAR pseudotime differentiation. Gray shades represent standard error. CAR, Cxcl12⁺ abundant reticular; CTRL = Control; UMAP: Uniform Manifold Approximation and Projection; Ery, erythrocytes; IF TX, intrafemoral transplantation; Reti, reticulocytes.