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 of different types, such as salivary gland, thymic epithelial, subcutaneous sarcomas, hair follicle, mammary, ameloblastomas, and renal medullary sarcomas, were analyzed. The isozyme profiles were consistent and unique for each tumor type, except for salivary and mammary tumors, which shared a profile. Five specific isozymes could distinguish other tumor types. In contrast, nonpolyoma mammary tumors and spontaneous salivary myoepitheliomas showed variations in isozyme profiles. The study suggested that uniform isozyme phenotypes might be characteristic of DNA virus-induced tumors, unlike those associated with mouse mammary tumor virus, spontaneous, or chemically induced tumors.