Isozyme Phenotypes of Polyoma Virus Tumors in Mice

The study examined isozyme profiles in tumors induced by two strains of polyoma virus in various mouse strains, including conventional and athymic mice. A total of 174 tumors were analyzed, including salivary gland, thymic epithelial, subcutaneous sarcomas, hair follicle, mammary, ameloblastomas, and renal medullary sarcomas. The isozyme profiles were consistent and unique for each tumor type, except for salivary and mammary tumors, which shared a profile. Five isozymes were sufficient to distinguish between different tumor types. Nonpolyoma mammary tumors and spontaneous salivary myoepitheliomas showed variations in isozyme profiles, indicating that uniformity of isozyme phenotype might be specific to DNA virus-induced tumors, unlike those associated with mouse mammary tumor virus or spontaneous tumors.