IL-7⁺ and GAL1⁺ stromal cells are localized in distinct regions of the BM. BM sections were stained to determine the organization of the whole stroma and of IL-7⁺ and GAL1⁺ stromal cells compared with the extracellular matrix (A-C) and the vasculature (D-E). Representative BM sections are shown. (A) Staining of BM sections of stroma-GFP mice with anti-GFP and anticollagen IV antibodies (original magnification 40×/1.25 NA oil objective). (Right panels) A magnification of the region in the dotted square of the left panel. (B) Staining of BM sections of IL-7-GFP reporter mice with anti-GFP and anticollagen IV antibodies. (C) Staining of BM sections of stroma-GFP mice with anti-GFP, anti-GAL1, and anticollagen IV antibodies. (D) Staining of BM sections of IL-7-GFP reporter mice with anti-GFP, anti-laminin antibodies, and Sytox Blue (nuclei). (Right panels) A magnification of the region in the dotted square of the left panel. (E) Staining of BM sections of stroma-GFP mice with anti-GFP, anti-GAL1, anti-laminin antibodies, and Sytox Blue (nuclei). (Right panels) A magnification of the region in the dotted square of the left panel. (A,D-E) Bar represents 50 μm. (B-C) Bar represents 10 μm. Images acquired on Leica SP5X and analyzed with ImageJ 1.44.