Figure 6. Maintenance of proper BM hematopoiesis by the vascular niche requires endothelial ERG and Fli1 expression.

Samples from control (Ctl) mice are labeled in blue and from dKO mice are labeled in red. n = 5 mice. Student t-test two sided analysis was performed ±SEM. a, Bone tissues of Control and dKO mice at day 12 injected i.v. with EBD. EBD Quantification in the BM of Ctl and dKO mice. b, Number of PB white blood cells (WBC) at day 12 as determined by HESKA veterinary hematology system. c, Number of colony forming units (CFU) per 2X10⁵ PB WBC plated in methylcellulose as scored after 1 week. d, Frequency of PB LSK HSPC was determined by flow cytometry and numbers were calculated relatively to PB WBC counts per mouse. e, Frequency of PB SLAM LSK HSPC was determined by flow cytometry and numbers were calculated relatively to PB WBC counts per mouse. Representative flow dot plot images for the SLAM markers CD150 and CD48 after pre-gating for Ter-119^negLSK cells. Red labeled dots represent CD150⁺CD48^neg LSK HSPCs in the PB. f, BM H&E images of of Control and dKO mice at day 12. Enlarged areas display perivascular megakaryocytes. Scale bar = 100 μm. g, Number of BM white blood cells (WBC) as determined by haematocytometer counting using Turk dye. h, Frequency of BM LSK HSPC was determined by flow cytometry and numbers were calculated relatively to BM WBC counts per mouse. i, Frequency of BM SAM LSK HSPC was determined by flow cytometry and numbers were calculated relatively to BM WBC counts per mouse. j, Representative flow density plot images for the SLAM markers CD150 and CD48 after pre-gating for Ter-119^negLSK cells. Green labeled areas surrounded by a dotted line represent CD150+CD48^neg LSK HSPCs in the BM. k-m, Frequencies of PB lymphocytes, monocytes, and granulocytes as determined by HESKA veterinary hematology system.