Cross-correlation of surface marker-based niche cell identification with lineage marker/tracer approaches in the BM. (A) Representative gating using Nestin-GFP⁺ mice to determine the composition of reporter-positive cells (top). Reporter-positive cells were analyzed for surface marker expression identifying endothelial cells (green), MSCs (blue), and OPs (red). Composition of reporter-positive cells is shown as pie charts. The contribution of reporter-positive cells to each niche cell type identified by flow cytometry is shown in bar charts (bottom). (B) Composition of niche cell types identified in BM reporter-positive cells using indicated reporter mouse strains. For comparison, proportional niche cell composition in the marrow fraction of wild-type mice is shown. VE-cadh-cre⁺;eYFP^ki/wt mice: 13% ± 5% of hematopoietic cells (hema) are labeled (not shown), and 99.7% of all labeled cells also express CD45 (left circle). Composition of nonhematopoietic–labeled cells (non-hema) is shown in the right circle. (C) Contribution of reporter-positive cells to each niche cell type. Wild-type (wt): n = 50, 30 experiments; Nestin-GFP⁺: n = 14, 4 experiments; Cxcl12-DsRed^ki/ki: n = 17, 4 experiments; Osx-cre⁺;tdRFP^ki/wt: n = 18, 8 experiments; Prx1-cre⁺;tdRFP^ki/wt: n = 17, 6 experiments; Lepr-cre⁺;tdRFP^ki/wt: n = 31, 12 experiments; VE-cadh-cre⁺;eYFP^ki/wt: n = 9, 2 experiments. GFP, green fluorescent protein.