Genetically dominant resistance in mice to 3-methylcholanthrene-induced lymphoma.

Mice of the RF/J strain are highly susceptible to induction of thymic lymphoma by skin painting with 3-methylcholanthrene (MCA), whereas mice of the 129/J and I/LnJ strains are resistant. Resistance was the dominant trait in F1 mice of crosses of RF with each resistant strain. Analysis of the lymphoma incidence in MCA-painted backcross populations indicated segregation of a single dominant gene for resistance in both crosses. None of these strains show inducibility of the aryl hydrocarbon hydroxylase enzyme system, a phenotype attributed to the dominant Ahb gene which is also known to influence susceptibility to MCA-induced lymphoma. The occurrence of the disease in these backcrosses was independent of the hosts' phenotype at either the H-2 or Fv-1 locus, both of which have shown an influence on susceptibility to murine leukemia virus-associated lymphoma in other experimental systems.