[Phenomenon of parental resistance and its genetic regulation]

Lymphocytes of mice F1 (CBA X M523) and F1 (A X M523) transplanted to 1000 R irradiated CBA or A mice responded to the test antigens--SRBC or S. typhi Vi-antigen--by formation of 100--1000 times less antibody forming cells than in syngeneic recipients. An intermediate result is achieved when the lymphoid cells are transplanted to the irradiated M523 mice. Lymphocytes of mice F1 (A X CBA), F1 (CBA X C57Bl/6), or F1 (A X A.CA) developed a similar immune response in the irradiated syngeneic mice and in both parental lines. The ability of parental line M523 to respond to SRBC was the same as in the other lines studied when examined in situ or in adoptive transfer experiments. The stem hemopoietic cells of mice F1 (CBA X M523) develop in the spleen of CBA mice 2--2.5 times less hemopoietic colonies than in the spleen of syngeneic animals. A conclusion was drawn that mutation M523 in CBA mice inhibited the proliferation and differentiation of hemopoietic and lymphoid cells in the irradiated nonsyngeneic recipients.