© 1973 by The Society for Integrative and Comparative Biology
The Lucké Frog Kidney Tumor and its Herpesvirus
Department of Zoology, University of Minnesota Minneapolis, Minnesota 55455
Northern leopard frogs are afflicted with a spontaneous malignant neoplasm of the mesonephros. A herpesvirus is invariably associated with tumors obtained from frogs hibernating 30 days or longer and in tumors of frogs taken from breeding ponds. Tumors obtained from prehibernating frogs do not have viruses as detected by electron microscopy but virus particles are found in some tumors within 7 days after the onset of hibernation. Tumors of frogs maintained at warm temperature in the laboratory do not have viruses and tumors of frogs maintained at cold temperatures in the laboratory do contain viruses. However, the production of viruses in the laboratory follows a distinctly slower chronology than that which occurs in nature. Injection of cell fractions containing the herpesvirus into frog embryos induces tumors near the time of metamorphosis in many experimental animals. Embryos injected with tumor extracts not containing herpesviruses do not develop tumors. Environmental and laboratory observations are discussed which may relate to natural transmission of this presumed viral oncogenic agent.