Genetic control of allogenic inhibition of haematopoletic stem cells

Adult mice of C57BL/6, CBA(CBAxC57BL/6)F1, (CBAxC57BL/6)F2, F1xCBA and F1xC57BL/6 strains have been lethally irradiated and reconstituted with a constant dose of 3x105 C57BL/6 bone marrow cells. On the 9th day after the bone marrow transplantation the colony count has been performed in the spleen of irradiated recipients. In the spleen of E1, CBA and C57BL/6 mice have been registered low (0-8), intermediate (6-18) and high (22-40) numbers of colonies respectively. The segregation ratios in F2 progeny prove close to 2(low): 1 (intermediate): 1 (high). The segregations ratios in back-cross (Fsub(1xCBA)) are close to 1 (low) : 1(intermediate) numbers of colonies. Back-crosses (F1xC57BL/6) are distributed to low and high numbers of colonies with the ratio 1 : 1. The number of spleen colonies of males and females has been the same in all the segregating progeny. The results of hybrid analysis suggest that a single pair of allelic genes is involved in genetic control of allogenic inhibition, and that the resistance (manifestation of inhibition) to C57BL/6 stem cells is conferred by the dominant allele