Figure 3

CD4⁺ CD8⁺ cell survival after γ-ray irradiation. A) CD4⁺ CD8⁺ cell survival after γ-ray irradiation. Cell survival was highest (apoptosis was lowest) in the double hemizygous background. In contrast the percent of CD4⁺ CD8⁺ cells does not depend of the genotype in nonirradiated cells. The numbers of mice used was three per genotype for the controls and five per genotype for the irradiated mice. B) Representative image of flow cytometry of the thymocytes. Top panel: Atmwt/Brca1wt genotype. CD4⁺ CD8⁺ cells appear at the upper right quadrant and are 31% of the total cell numbers. Note also the very low numbers of CD4⁺ and CD8⁺ cells which appear in the lower right and upper left quadrants. Lower panel represents Atmhz/Brca1hz genotype where 61% of the double positive CD4⁺ CD8⁺ cells survived accompanied also with high numbers of CD4⁺ and CD8⁺ cells (lower left and upper right quadrants).