T cell development on OP9-DL1 cells.

Hematopoietic stem cells (Lin− CD117+ Sca1+) isolated from bone marrow were co-cultured with OP9-DL1 cells and analyzed by flow cytometry. The proportion of DN2, DN3 and DP cells gated on CD45+ are shown on days 7, 10, 14 and 18. Analysis for the expression of CD44 and CD25 were additionally gated on CD4− CD8− CD11b− CD19− and B220− cells. Data are derived from 2–3 independent experiments. All experiments were performed using female mice, 8–12 weeks old. Each experiment included age-matched sets of knockout and wild-type mice. Statistical analysis was performed using Prism Graph Pad. Student's t-tests revealed no significant differences in cell populations between wild-type and Tacr1−/− mice.