Fig. 2

Proposed pathways for the production of T-cells in postpubertal mice. Progenitor cells enter the thymus via postcapillary venules (PCVs) located in the medulla and as T-cells leave by way of efferent lymphatic vessels (ELVs) located in the subcapsular cortex and in the medulla. In postpubertal mice, mast cell activation (red dots) results in large numbers of thymocytes exiting the classic pathway as DN T-cells and entering the LS (solid red arrows) via ELVs located in the subcapsular region. Lesser numbers of thymocytes remain in the classic pathway and enter the LS (dashed red arrows) as SP T-cells via ELVs located in the medulla