Percent male phenotype expressed as a fold increase over age-matched nonirradiated controls in each experiment.
The data presented in Figure 4 are presented here as a fold increase engraftment in postirradiation female mice given as 40 × 106 male BALB/c cells compared with engraftment seen when age-matched nonirradiated mice are infused with 40 × 106 male BALB/c cells. There were statistically significant differences between 0 and 1 Gy in each experiment and at each week (Wilcoxon rank sum test, P ≤ .02). The time effect was assessed in matched experiments using the ANOVA method, adjusting in the model for experimental effect and possible interactions and stratifying by radiation level (ie, separately for 0 and 1 Gy). At 0 Gy, no significant differences in engraftment at the different time points were observed. At 1 Gy, engraftment data at 6 and 12 weeks were significantly different from that of 0 weeks (P < .0002). No difference between 6 and 12 weeks was observed. Data are expressed as a mean ± 1 SD.
