Cx43 regulates the cellular composition in nonmyeloablated BM. (A-B) Content of BM mesenchymal (CFU-F; A) and osteoblastic progenitors (CFU-OB; B) in BM of WT and OB/P Cx43-deficient mice. (C-E) Quantification of immunophenotypically identified nonhematopoietic cells (C) and cadherin-11 negative (D) or positive (E) subpopulations. (F-G) OB/P-Cx43–deficient mice showed an increased number of Cxcl12⁺ cells among both CD45⁻/Ter119⁻/cadherin-11⁺ and CD45⁻/Ter119⁻/cadherin-11⁻ cell subpopulations. (H) Representative example of flow cytometry analysis of 5-bromo-2'-deoxyuridine (BrdU⁺) cells on different mesenchymal cell subpopulations. (I) In vivo proliferation of BM CD45⁻/Ter119⁻ and Cxcl12⁺ mesenchymal cells. (J) Normalized RNA expression of sclerostin in cortical bones from WT or OB/P Cx43-deficient mice. Results for sclerostin expression are presented as average of 2 mice per group where expression was analyzed in femora, tibiae, and pelvic cortical bones. Empty bars present control data; solid bars represent data from OB/P Cx43 deficient mice. Analysis of OB/P populations are shown as mean ± SD. N = 3 different experiments n = 6 mice per group (*P < .05; **P < .01).