Elevated bone marrow and spleen erythropoiesis in Lyn^+/up and Lyn^up/up mice. (A) Bone marrow BFU-E and CFU-E numbers are increased in Lyn^+/up and Lyn^up/up adult mice. Erythroid colony assays (BFU-E and CFU-E) of bone marrow from Lyn^+/+, Lyn^+/up, and Lyn^up/up adult mice (8 weeks) (n = 4 in 2 independent experiments, *P < .05, ns, not significant). (B) Extramedullary erythropoiesis in spleen of Lyn^+/up and Lyn^up/up adult mice. Erythroid colony assays (BFU-E and CFU-E) of spleens in Lyn^+/+, Lyn^+/up, and Lyn^up/up adult mice (8 weeks) (n = 4 in 2 independent experiments, *P < .05, **P < .001, ***P < .001). (C) Lyn^up/up and Lyn^+/up adult mice display spleen reduction compared with controls and in contrasts to Lyn^−/− animals that show splenomegaly. Spleen wet weight of adult mice (12-15 weeks) of the indicated Lyn genotypes (n > 6, *P < .05). (D) Comparison of maturing bone marrow erythroid cells from Lyn^up/up and Lyn^+/+ adult mice. Representative flow cytometric analysis of bone marrow cells from Lyn^+/+ (WT) and Lyn^up/up mice (12-15 weeks) using anti-CD71 and anti-Ter119 and enumeration of the indicated erythroid subsets (R1, R2, R3, R4; n > 3, *P < .05).⁴⁹  (E) Elevated maturing erythroid cells in the spleen of Lyn^up/up adult mice. Representative flow cytometric analysis of spleen cells from Lyn^+/+ (WT) and Lyn^up/up mice (12-15 weeks) using anti-CD71 and anti-Ter119 and enumeration as in D.