Defective lymphopoiesis in the bone marrow of motheaten (me/me) and viable motheaten (mev/mev) mutant mice. III. Normal mouse bone marrow cells enable mev/mev prothymocytes to generate thymocytes after intravenous transfer

Bone marrow prothymocytes from me/me and mev/mev mutant mice fail to generate thymocytes in irradiated (600 rad) +/+ wild-type recipients after intravenous injection. However, these same prothymocytes readily generate thymocytes after intrathymic injection. The results of the present study demonstrate that this apparent defect in the thymus- homing capacity of mev/mev prothymocytes can be corrected by mixing irradiated wild-type bone marrow cells with mev/mev bone marrow cells before intravenous injection. However, this defect is not corrected by passage of mev/mev bone marrow cells through the bone marrow of irradiated wild-type recipients. One interpretation of these results is that the maturation of prothymocytes is reversibly arrested in mev/mev mice by a defect in the radiosensitive compartment of the bone marrow microenvironment.