Figure 11.

The megakaryocytes in the femur of Gata1^low mice contain high levels of BMP-4 and are localized in close proximity to microvessels and bone trabeculae. (A) Representative sections of the femur from two representative wild-type and Gata1^low mice immunostained for BMP-4 and counterstained with hematoxylin. Arrows indicate megakaryocytes, red dashed lines indicate the contour of the microvessels, and yellow dashed lines indicate the contour of the bones. Magnification 40×. (B) Quantification of the megakaryocytes expressing BMP-4 in the bone marrow of young and old wild-type and Gata1^low littermates, as indicated. Results are presented as mean (±SD) and as values of individual mice (each dot an individual mouse). p values were calculated with Tukey multiple comparison, and those statistically significant are indicated in the panels. Abbreviations: WT: wild-type; MKs: megakaryocytes, BMP-4; bone morphogenetic protein 4.