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. 2001 Feb;21(3):703–712. doi: 10.1128/MCB.21.3.703-712.2001

FIG. 3.

FIG. 3

FIG. 3

Increased sensitivity of mad3−/− thymocytes to gamma irradiation. (A) Thymocytes from mad3+/+ and mad3−/− mice were left untreated (medium), treated with gamma irradiation (200 rads), and then incubated in tissue culture medium containing no addition (medium or 200 rads), PMA (2 ng/ml) (PMA), dexamethasone (1 μM) (DEX), or ionomycin (1 μg/ml) (ION). Death was determined 24 h after culture by the trypan blue exclusion method. (B) Dose response of mad3+/+ and mad3−/− thymocytes to gamma irradiation. Decreased survival of mad3−/− thymocytes is observed at 100, 200, 500, and 1,000 rads at 24 h after culture. (C) Determination of the proportion of annexin-positive cells is an independent measurement of the increased apoptosis in mad3−/− mice in response to gamma irradiation. Thymocytes harvested from mad3+/+ and mad3−/− mice were subjected to 200-rad irradiation. The binding of annexin and the extent of apoptosis were determined by fluorescence-activated cell sorting 24 h after irradiation. (D) Loss of mad3 does not influence cell cycle entry in thymocytes. Thymocytes harvested from mad3+/+ and mad3−/− mice were stimulated by concanavalin A. Cell cycle entry was monitored by BrdU incorporation analyzed by fluorescence-activated cell sorting.