The H-2 complex affects the frequency of urethan-induced chromosomal aberrations.

We have already found that H-2 complex has an apparent effect on the development of lung tumors in mice. In connection with this finding, the incidence of in vivo urethan-induced chromosomal aberrations of bone marrow cells was examined in H-2 congenic strains. These strains could be divided into two groups, one with a higher frequency of chromosomal aberrations such as A.AL (H-2a1), A.TL (H-2t1), B10.A (H-2a) and B10.S (9R) (H-2t4), and the other with a lower incidence such as B10 (H-2b), A.SW (H-2s), B10.S (H-2s) and B10.S(7R) (H-2t2). These results suggested that a putative gene mapped to the chromosomal segment between E beta and D may affect the incidence of urethan-induced chromosomal aberrations.