Genetic linkage of nuclear morphology of mouse lung tumors to the Kras-2 locus

Search for quantitative trait loci (QTLs) has been successful in the past decade by revealing numerous susceptibility to lung cancer loci in specially designed experimental crosses in mice. Although qualitative aspects of lung tumorigenesis are also genetically controlled, no loci affecting such traits have so far been identified. We analyzed a series of lung tumors derived from various inbred and recombinant congenic strains and F2 crosses for two histological characteristics: nuclear cytoplasmic invaginations (NCIs) and lymphocytic infiltration (LI) and performed linkage analysis. A significant linkage of the Kras-2 locus with presence or absence of NCI was detected. The implications of this linkage as well as the relationships between NCI, LI, tumor size and Kras-2 alleles are discussed.