Relationship between pre-BMT radiation dose and donor-derived thymic subpopulations on day 28.

Mean percentages of TN (■), DP (▪), SP CD4 (▨), and SP CD8 (░) thymocytes from the control group and the 3 groups of mice transplanted after either 1000, 1200, or 1400 cGy are shown. Each histogram represents mean percentage ± SD. Differences between groups were analyzed by 2-tailed t test with unequal distributions. For TN cells, P < .02 (normal vs 1400 cGy),P < .01 (1000 cGy vs 1400 cGy), and P > .05 (all other comparisons). For DP cells, P < .02 (normal vs 1400 cGy), P < .01 (1000 cGy vs 1400 cGy),P < .01 (1200 vs 1400 cGy), and P > .05 (all other comparisons).