Megakaryocytes in the bone marrow and spleen of double mutant mice.

Megakaryocyte numbers in histologic sections of sternal marrow and spleen from wild-type (wt) mice and mice lacking c-mpl, LIF, IL-6, IL-11 receptor alpha-chain (IL-11Rα) or combinations of these genes are shown. The means ± SD of megakaryocyte numbers per 30 high power fields (bone marrow, × 400; spleen, × 200) were calculated from samples taken from 2 to 9 mice per genotype. *P < .05 for comparison of LIF^-/-, IL-6^-/-, or IL-11Rα^-/-with wt or of LIF^-/-mpl^-/-, IL-6^-/-mpl^-/-, or IL-11Rα^-/-mpl^-/- withmpl^-/-. No other statistically significant differences were observed.