Tlag2, an N-methyl-N-nitrosourea susceptibility locus, maps to mouse chromosome 4

Susceptibility to N-methyl-N-nitrosourea (MNU)-induced lymphomas is a multigenic trait. We previously mapped a resistance locus (Tlagl) to mouse chromosome 7 in genetic crosses of sensitive AKR with resistant C57L mice. Analysis of the MNU sensitivity of AKXL recombinant inbred strains that are homozygous for the AKR allele of Tlag1 suggested that at least two additional tumor susceptibility loci segregate in these crosses. A second susceptibility locus (Tlag2) now has been mapped to chromosome 4. Only those mice that inherited the susceptibility alleles at both Tlagl and Tlag2 were sensitive to MNU induction of thymic lymphomas, suggesting that these two loci interact. Chromosome 4 has been associated with susceptibility to hematopoietic tumor development in several mouse models, suggesting that one or more genes mapping to this chromosome are important in lymphomagenesis in general.