Genetic control of resistance to 3-methylcholanthrene-induced T-cell lymphoma in mice

Abstract

Different strains of inbred mice exhibit different levels of susceptibility to T-cell lymphoma induced by the carcinogen 3-methylcholanthrene (MCA). Resistance to MCA-induced lymphoma was dominant over susceptibility in all crosses tested, and in inbred strain mice MCA resistance was found to correlate with resistance to lymphoma induced by a fractionated dose of gamma irradiation. The susceptible RF/J strain was also found to be extraordinarily sensitive to lymphoma induction by low doses of X-irradiation; this low dose sensitivity was also recessive. Experiments on both first and second generation backcross populations supported the hypothesis that a single locus is the main determinant of MCA resistance. Studies examining the possible linkage of low lymphoma incidence to a number of loci failed to establish any clear association, but linkage was seen between the Lyt-2 locus and a significant delay in MCA-induced lymphoma development. We also examined the strain distribution of several activities which might have been expected to have an effect on susceptibility to induced lymphoma. No correlation was seen between resistance and either DNA repair ability, thymic superoxide dismutase levels, or natural killer activity.