Reduced bone marrow engraftment in diabetic ataxia telangiectasia mutated (ATM)−/−→wild type (WT) chimeras. (A): Demineralized mouse femurs were stained for n-cadherin (red) and c-kit (green) antibodies to identify long-term repopulating (LTR)-hematopoietic stem cells (HSCs). Representative photomicrographs from respective groups showing c-kit positive cells (white arrows) in an endosteal niche (open arrow) while bar chart showing a quantification of LTR-HSCs. (B): Mouse femurs stained with ve-cadherin (red) to define the vascular niche. c-kit+ cells (white arrows) in ve-cadherin positive regions identified as short-term repopulating (STR)-HSC. Bar chart showing ratio of STR-HSCs to LTR-HSCs. Scale bar = 20 μm. WT (n = 6), WT→WT (n = 4), WT+ STZ (n = 5), WT→WT + STZ (n = 7), ATM−/−→WT (n = 5), ATM−/−→WT (n = 5). Statistical Test- One way analysis of variance followed by Student’s Newman Keul Test. Abbreviations: ATM, ataxia telangiectasia mutated; HSC, hematopoietic stem cell; LTR, long-term repopulating; STZ, streptozotocin; WT, wild type.