Serial transplantation of male/female chimeric marrow from 1 Gy– engrafted hosts.

Cells harvested from 0- or 1 Gy–exposed female hosts 8 weeks after infusion of nonirradiated or 1 Gy–exposed marrow were serially transplanted at 8-week intervals at 20 × 10⁶ marrow cells into 10 Gy–exposed secondary or tertiary female BALB/c hosts. Marrow engraftment was determined in each instance 8 weeks after transplantation. The first category (* /) represents the treatment of the marrow in the initial transplant into 0- or 1 Gy–treated hosts. The second category (/*) represents the treatment of the original female BALB/c host. Data are expressed as a mean percentage engraftment (FISH) ± 1 SD. ▪ indicates secondary; ■, tertiary.