Fig. 1.
Methotrexate resistance of sublethally irradiated mice transplanted with DHFR transgenic marrow.
Normal male mice were given 1, 2, or 4 Gy TBI one day before they underwent transplantation with 1 × 107 marrow cells from female line 04 (Tg04) DHFR transgenic donors. They were then administered either PBS or MTX (up to 4 mg/kg) daily for 60 days (n = 10 for each group). (A) Kaplan–Meier plot showing the fraction of surviving mice per time in the MTX- administered groups. (B) Mean weekly hematocrit of surviving mice in the MTX-administered groups at each time point.