Deletion of IGF-1 in Osx+ Cells Phenocopied OsxCre;iDTR Lymphoid Defects
To delete IGF-1 in Osx+ cells, we crossed the Osx1-GFP::Cre mouse with the IGF-1F/F strain.
(A) Osx1-GFP::Cre+;IGF-1F/F mutants showed increased Mac1+ and Gr1+ myeloid cells, and decreased B lymphoid cells in the bone marrow. Three independent experiments; n = 8–14/group.
(B) Lymphopenia was also reflected in the peripheral blood. Experiment repeated once; n = 4–6/group.
(C) Osx1-GFP::Cre+;IGF-1F/F mutants showed a loss of mature B cells due to differentiation arrest at the pro-B to pre-B transition. Analysis of B cell differentiation showed accumulation of cells at the B′, C′, and C″ pro-B cell stages, but decrease in number at the pre-B, immature B, and mature B stages. Three independent experiments; n = 8–14/group.
∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. Error bars represent ± SEM.