Depletion of circulating CD117^hi or CD127⁺ precursors does not abrogate T-cell differentiation. (A) Flow cytometric analysis of lin⁻ cells from BM (top panels) and blood (bottom panels). Cells were stained with antibodies against lineage markers CD90, CD117, CD127, CD27, Sca-1, and CD135. Numbers indicate frequencies of cells within gates. BM cells from 5 mice and blood cells from 10 mice were pooled for analysis. Plots are representative of 3 independent experiments. (B-C) Lin⁻ blood cells from 20 B6 CD45.2 mice (blood) were depleted of CD117^hi cells or CD127⁺ cells, mixed with lin⁻ BM cells from B6 CD45.1 mice (BM), and transferred intravenously into sublethally irradiated Il7ra-deficient hosts. Ctl indicates mixture of nondepleted B6 CD45.2 lin⁻ blood cells with B6 CD45.1 lin⁻ BM cells. Donor-derived thymocytopoiesis was analyzed flow cytometrically by staining for CD45.1 and CD45.2 (B) as well as CD4 and CD8 (C). Numbers indicate frequencies of cells within gates or quadrants. Data are representative of 2 independent experiments with 2 to 3 recipients per group.