Figure 5.
The number of colony-forming units thymus are reduced in aged D2 but not in B6 mice. Shown is the frequency of CFUt per 105 cells injected in B6 (left panel, mean and SD of 3 experiments) and D2 mice (right panel, 1 experiment using 20 hosts). Animals were injected with mixtures of young (y) and aged (a) BM with an excess of host-type BM. CFUt frequencies were calculated from the number of mice that had thymic donor-type cells derived from either the aged or the young donors at 4 weeks. For details, see “Colony-forming unit thymus assay.”