Release of (pro)platelet-like particles into the BM compartment of Adap^−/−mice. (A) Representative confocal microscopy images of immunostained cryosections from femura of control and ADAP-deficient mice. Sinusoides (red, CD105), MKs (green, GPIX), and nuclei (blue, DAPI). Scale bars represent 30 µm and 10 µm (insets). (B-D) Gating strategy and analysis of (pro)platelet-like particles (CD41⁺) in the BM by flow cytometry. Values are mean ± SD (n = 3). **P < .01; *P < .05. (E) Ploidy level of BM MKs was assessed by flow cytometry. Values are mean ± SD (n = 6; **P < .01). (F) Analysis of localization of nonfragmented MKs in the BM based on cryosections. Three categories were defined: vessel contact (MKs with contact to sinusoids); BM (MKs in the BM compartment with no contact to sinusoids) and intrasinusoidal (MKs inside the sinusoid lumen). Values are mean ± SD. Three cryosections per femura from each genotype (3 vs 3 mice) and at least 5 images per cryosections were analyzed.