Figure 6.

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-1^F/F strain.

(A) Osx1-GFP::Cre⁺;IGF-1^F/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-1^F/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.