Thrombocytosis in CALR^del/+mice is transplantable. (A) Plasma THPO level is not significantly altered in CALR^del/+ mice. (B) Donor chimerism is comparable in the primary noncompetitive BM transplants. BM cells from CALR^del/+ or control mice (2 × 10⁶ per recipient) were transplanted into irradiated (2 × 550 cGy) CD45.1 C57BL/6 recipients. Donor chimerism in peripheral blood was analyzed by using flow cytometry with CD45.1 and CD45.2 antibodies and was derived as a percentage of CD45.2⁺ cells in whole nucleated blood. (C) Time course of blood counts showing significantly increased platelet counts in the recipients of CALR^del/+ BM. (D) Time course of blood counts showing significantly increased platelet counts in the secondary transplant recipients of CALR^del/+ BM. BM cells from the primary recipients of CALR^del/+ or control BM (5 × 10⁶ cells per recipient) were transplanted into irradiated (1 × 400 cGy) Kit^W41/W41 (CD45.1) recipients. (E) Donor chimerism was comparable in the secondary noncompetitive BM transplants. Donor chimerism in peripheral blood was analyzed by using flow cytometry as above. Data are shown as mean ± SEM. *P < .05; ***P < .001.