The influence of the thymus on precursor T cells.

The influence of the thymus on its bone marrow precursors was investigated: T cell differentiation was studied in irradiated mice reconstituted with bone marrow from thymectomized donors. Up to twelve months after TX the influx of precursors and differentiation into T cells were not changed in the recipients. CFU-s determination of bone marrow and spleen from thymectomized animals did not show a change in numbers but during ageing a shift of the E/G ratio was observed in thymectomized as well as control donors.