Cell cycle and proliferative status of Hmgb3^–/Y primitive hematopoietic cells. (A) Representative cell cycle histograms obtained through PI staining of wild-type (left) and Hmgb3^–/Y (right) HSCs (lin^–, c-kit^HI, Sca-1^HI, IL-7Rα^–). Staining was performed on cells pooled from 3 mice of each genotype. Analysis of histograms performed as described in “Materials and methods.” (B) Representative cell cycle histograms obtained through PI staining of wild-type (left) and Hmgb3^–/Y (right) multipotent and oligopotent progenitor cells (MPPs: lin^–, c-kit⁺). Staining was performed on cells pooled from 3 mice of each genotype. (C) Percentages of both wild-type and Hmgb3^–/Y Lin^–, c-kit⁺ bone marrow cells in G₁, S, and G₂ phases (n = 3). The data represent the pooled results of 3 independent experiments. (D) Percentages of wild-type (n = 3) and Hmgb3^–/Y (n = 3) HSCs, CLPs (lin^–, c-kit^LO, Sca-1^LO, IL-7Rα⁺), CMPs (lin^–, c-kit⁺, Sca-1^–, IL-7Rα^–), and myeloid progenitors (MPs: lin^–, c-kit^LO, Sca-1^–, IL-7Rα^–) that incorporated BrdU. The data represent the pooled results of 3 independent experiments using pooled bone marrow from 3 mice. (E) Average concentration of nucleated peripheral blood cells following mobilization of splenectomized wild-type (n = 10, □) and Hmgb3^–/Y (n = 10, •) mice with 200 μg/kg/d G-CSF. Peripheral blood cells were counted starting on the day of the first treatment and were counted every day 24 hours after the last treatment. The data represent the pooled data from 2 independent experiments involving at least 5 animals in each group. Error bars in panels C-E represent standard deviation. P values were determined by Student t test.