Abstract
Transgenic mice carrying activated v-Ha-ras under the control of mouse mammary tumor virus (MMTV) long terminal repeat were produced. The introduced gene was transmitted in the Mendelian fashion from a founder transgenic male to a total of 49 first-, 45 second- and 16 third-generation progeny, with a stochastic tumor occurrence ranging from 39 to 56%. The most common primary lesions were hyperplasia, adenoma and/or adenocarcinoma of Harderian lacrimal, salivary and mammary glands. Majority of primary tumors in the females occurred during their nulliparous state, though the MMTV promotor is known to be responsive to pregnancy/lactation-related hormones. The second-generation progeny segregated into 2 subgroups characterized by high (77%) and low (9%) risk of tumorigenesity, suggesting an influence of genotype on the appearance of the proliferative disorders caused by the activated v-Ha-ras oncogene.
