ALLELOTYPE ANALYSIS OF MOUSE SKIN TUMORS USING POLYMORPHIC MICROSATELLITES - SEQUENTIAL GENETIC ALTERATIONS ON CHROMOSOME-6, CHROMOSOME-7, AND CHROMOSOME-11

Allelotype analysis of human tumors has been instrumental in the effor t to discover and clone novel tumor suppressor genes. However, this ap proach has not been systematically applied to animal models of carcino -genesis. We describe here the first attempt to allelotype a nonhuman tumor, i.e., chemically induced mouse skin tumors, using a panel of po lymorphic microsatellite markers. The results indicated that markers o n chromosomes 6 and 7 were imbalanced, consistent with trisomy in both benign and malignant skin tumors. A proportion of carcinomas also sho wed loss of heterozygosity on chromosome 11, where the p53 gene is loc ated, and more rarely, on chromosomes 4, 6, and 15. The significance o f these alterations is highlighted by the observations of no allelic i mbalance for markers on 12 other chromosomes.